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Suggested Citation:"2 Coastal Mapping Needs and Activities." National Research Council. 2004. A Geospatial Framework for the Coastal Zone: National Needs for Coastal Mapping and Charting. Washington, DC: The National Academies Press. doi: 10.17226/10947.
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2
Coastal Mapping Needs and Activities

One of the more difficult challenges for the Committee onNational Needs for Coastal Mapping and Charting was the identification of the needs and activities of the extremely large and diverse community involved with spatial information in the coastal zone. The intersection of these needs and activities formed the basis for identifying gaps and overlaps in coastal zone data collection and processing. In order to assess both the needs and activities, committee members and National Research Council (NRC) staff interviewed representatives of, and solicited written submissions from, agencies involved in coastal zone mapping and charting. In addition, a series of presentations were made to the committee by representatives of a wide range of agencies and organizations that use and/or produce information related to the coastal zone. Valuable additional information was also extracted from the National Oceanic and Atmospheric Administration (NOAA) Coastal Services Center (CSC) surveys of coastal resource managers (CSC, 1999; 2002); a CSC-sponsored study of the benefits of Geographic Information Systems (GISs) for state and regional ocean management (Good and Sowers, 1999); and a National Marine Sanctuaries evaluation of the status and needs of spatial information in marine sanctuaries (NOAA, 2002).

Based on this data collection and information-gathering process, the committee identified at least 15 federal agencies, almost all coastal states, and innumerable local agencies, academic institutions, and private companies involved in the collection or production of coastal mapping and charting data or products. While an attempt was made to quantify expendi-

Suggested Citation:"2 Coastal Mapping Needs and Activities." National Research Council. 2004. A Geospatial Framework for the Coastal Zone: National Needs for Coastal Mapping and Charting. Washington, DC: The National Academies Press. doi: 10.17226/10947.
×

tures on coastal mapping and charting (each agency was asked to provide a reliable estimate of its annual expenditures on coastal mapping and charting), the inconsistency of responses made it impossible to provide a precise (or even approximate) total. It is clear, though, that hundreds of millions of dollars are spent each year on coastal zone mapping and charting activities. The Office of Management and Budget (OMB) had hoped to compile a comprehensive accounting of the federal dollars spent on geospatial data collection in 2002, for publication in early 2003. However, difficulties encountered when attempting to collect these data resulted in the comprehensive compilation being deferred, with the intention that 2003 data should be available in early 2004. Therefore, although not available at the time of publication of this report, the information contained in the OMB study should finally allow a quantitative assessment of the amount of federal money spent on coastal zone mapping activities.

The information presented to the committee is summarized in Appendix A, based on the more extensive compilation presented in the committee’s interim report (NRC, 2003a). This information was reviewed by each agency for accuracy, but the perspective is ultimately that of this committee. Although state and local agencies play a key role in the acquisition and use of coastal geospatial data, the breadth and diversity of these activities prohibited an exhaustive review of each coastal state’s activities and needs.1 The committee found considerable commonality of needs and activities among the states and local agencies and accordingly has included a “generic” section on state and local needs and activities. An overarching expression of the needs of state and local agencies is probably best presented in the recent Coastal States Organization (CSO) submission to the U.S. Commission on Ocean Policy, which called for “complete mapping of the nation’s coastal areas, including near-shore topography and coastal watersheds, at a scale and in a form that is readily available and usable by the states and territories with an initial focus on critical areas under threat to the public or critical coastal or ocean resources.” The CSO also states that such a mapping program is needed because of the “lack of accurate mapping of flood plains, erosion zones and shorelines and accessible information to enable states and communities to make well-reasoned, cost-effective, long-term decisions” (CSO, 2002, p. 17).

While the committee has made every attempt to be as complete in its analysis as possible, the magnitude of coastal mapping activities across this nation is such that it is possible that some activities and needs have

1  

A state-by-state review of some activities is presented in the CSC-sponsored study of GISs for ocean management (Good and Sowers, 1999).

Suggested Citation:"2 Coastal Mapping Needs and Activities." National Research Council. 2004. A Geospatial Framework for the Coastal Zone: National Needs for Coastal Mapping and Charting. Washington, DC: The National Academies Press. doi: 10.17226/10947.
×

been missed. Nonetheless, the committee is confident that the major needs and activities of those involved in coastal mapping and charting in the United States have been addressed and, in so doing, a basis has been established for evaluating the gaps, overlaps, and major issues associated with current activities.

Analysis of the agency activities presented in Appendix A revealed that, while coastal zone mapping and charting applications are as varied and diverse as the user community, there is a strong thread of consistency and commonality in important elements of the communities’ needs. These commonalities include a need for:

  • A consistent spatial framework for coastal data that allows a seamless transition from onshore to offshore, including clarification of offshore boundary definitions.

  • A standardized definition of “the shoreline,” to the extent possible in the context of federal and state legal restrictions.

  • Increased collection and availability of primary thematic data, including such elements as shallow-water bathymetry, acoustic and satellite imagery of the seafloor, bottom type, habitat distribution and classification standards, land use, land cover, and coastal change data.

  • Easy access to up-to-date digital geospatial data, imagery, and mapping products.

  • Compatibility among data formats, or standards and transformation protocols that allow easy data exchange, and a means to evaluate the accuracy of geospatial data.

  • Increased inter- and intra-agency communication, cooperation, and coordination.

Addressing these critical issues, which are described in more detail below, will provide the basic reference frame, source data, and tools necessary to create the wide range of derivative products needed to efficiently and effectively manage the coastal zone.

COASTAL GEOSPATIAL DATA, TECHNOLOGY, AND PRODUCTS

The fundamental reference information for all geospatial data consists of the position of each data element in three-dimensional space. Within this context it is important to acknowledge the revolutionary advances in positioning capability that have taken place over the past 30 years. With the advent of universally available, relatively inexpensive global positioning system (GPS) receivers, almost all modern coastal zone data can now be collected with unprecedented accuracy (on the order of

Suggested Citation:"2 Coastal Mapping Needs and Activities." National Research Council. 2004. A Geospatial Framework for the Coastal Zone: National Needs for Coastal Mapping and Charting. Washington, DC: The National Academies Press. doi: 10.17226/10947.
×

10 meters for single-point GPS, 3 meters for differential and WAAS2-enabled GPS, and at the centimeter level for kinematic or carrier positioning systems3). As will be discussed later, the introduction of GPS also provides for a continuous vertical reference frame from which offshore and onshore data can eventually be compared. The ability to precisely locate the position of measurements removes an important level of uncertainty from coastal zone surveys and greatly aids in the ability to make meaningful repeat surveys (for time-series studies). It also emphasizes the critical need to understand and document the positional accuracy associated with historical data, especially when comparing GPS-positioned data to non-GPS-positioned data.

Throughout this report, this positional information will be referred to as reference frame data. Onshore, the vertical component of a position has involved measurements of the dynamic earth surface, determined by measuring the elevation of the land surface. Offshore, the vertical component is determined by measuring both the dynamic earth surface (the depth of water to the seafloor) and the dynamic water surface, determined by monitoring tidal levels (the water level with respect to an established reference surface [datum] at a given moment in a tidal cycle). Both horizontal and vertical measurements must be made relative to established horizontal and vertical reference frames (the vertical and horizontal datums) that have to be defined within the context of a survey. The Federal Geographic Data Committee (FGDC) introduced the concept of “framework data” as a common-use data layer—the geospatial foundation—upon which an organization can add additional detailed mapping information (FGDC, 1995). Reference frame data, as defined by the committee in this report, are a type of framework data consisting of fundamental geospatial position information (including the necessary geodetic controls).

The primary (nonderivative) properties of the coastal zone are represented by source data. Source data, and their associated metadata (data describing the data), include data from aerial and satellite imagery (conventional and digital photography as well as data generated by other imagery sensors), other remote sensors, and direct measurements or sampling. Properties often measured or sampled directly include sediment and soil type, soil moisture and porosity, salinity, temperature, turbidity, nutrient concentrations, and data describing plant and animal communities.

Numerous methods, platforms, and sensors are used to collect the framework and source data needed to produce coastal maps and charts (see Box 2.1). Bathymetry is most frequently collected using acoustic

2  

WAAS (Wide Area Augmentation System) provides correction information from a precisely surveyed ground reference station. See http://gpsinformation.net/exe/waas.html.

3  

See http://www.geod.nrcan.gc.ca/index_e/geodesy_e/gps-13_e.html.

Suggested Citation:"2 Coastal Mapping Needs and Activities." National Research Council. 2004. A Geospatial Framework for the Coastal Zone: National Needs for Coastal Mapping and Charting. Washington, DC: The National Academies Press. doi: 10.17226/10947.
×

BOX 2.1
Coastal Mapping and Charting Technology

1. REMOTE ACOUSTIC SENSORS

Acoustic sensors include underwater instruments that transmit and receive sound underwater to measure various parameters. The most common acoustic remote sensors are echosounders and sonars.

Overview of common seafloor mapping systems. SOURCE: U.S. Geological Survey (USGS) Coastal and Marine Geology Program.a

1.1 SINGLE-BEAM ECHOSOUNDER

The single-beam echosounder has been used extensively to determine water depths from vessels. This simple sounder measures the round trip time of an acoustic pulse emitted from a hull-mounted transducer and reflected, or echoed, from the seafloor back to the ship. Water depth is determined by converting the round-trip travel time into distance. Simple echosounders use an approximate speed of sound in water to make this conversion. More accurate echosounders use a separately measured acoustic velocity. Other factors are also taken into consideration to improve accuracy, including the vessel’s instantaneous heave, pitch, roll, squat, tide, and

Suggested Citation:"2 Coastal Mapping Needs and Activities." National Research Council. 2004. A Geospatial Framework for the Coastal Zone: National Needs for Coastal Mapping and Charting. Washington, DC: The National Academies Press. doi: 10.17226/10947.
×

sensors mounted on ships, launches, or autonomous underwater vehicles. Multibeam sonar systems are becoming increasingly important because they can provide complete high resolution coverage of the seafloor as compared to the sparse sampling of single-beam sonars. Acoustic backscatter from multibeam sonar systems and sidescan sonar systems provides bottom characterization information that can be used for habitat mapping and bottom geomorphology. If water clarity permits, airborne Light Detection and Ranging (LIDAR) systems can provide relatively high resolution bathymetry in depths up to 60 meters (although 20 to 30 meters is more typical). When coupled with a topographic LIDAR and the appropriate tidal and geodetic models, LIDAR can provide seamless measurements across the shoreline. Recent years have also seen a remarkable revolution in the spectral and spatial capabilities of airborne and spaceborne imaging sensors as well as the analytical tools available for the data derived from these sensors. Photogrammetric and multispectral imagery obtained from aircraft and spacecraft can now provide a wealth of data on land use, topography, habitat, biological, nutrient, suspended sediment, and shoreline data and in special circumstances can even provide some bathymetric data. Across the board, the capability of sensors and ancillary systems (e.g., positioning systems) is rapidly increasing, and these increases in capability (resolution, accuracy, etc.) will inevitably play an important role in future coastal zone mapping. In particular, the ability to collect coregistered datasets (e.g., sonar data combined with video data) and the development of software that will support data fusion and automated feature extraction will greatly facilitate the subsequent analysis and interpretation of complex coastal datasets.

Derivative or “value-added” products are created from the integration and interpretation of reference frame and source data. Most of these products fall into one or more of the following themes:

  • Safety of Navigation

  • Legal and Other Boundaries

  • Environmental Management and Protection

    Habitat and sensitive environments

    Water quality and pollutants

    Seafloor type and quality

    Living coastal resources

    Land-use characterization

  • Coastal Hazards

  • Minerals and Energy Management

  • Coastal Zone Planning and Development

  • Cultural Resource Management

Suggested Citation:"2 Coastal Mapping Needs and Activities." National Research Council. 2004. A Geospatial Framework for the Coastal Zone: National Needs for Coastal Mapping and Charting. Washington, DC: The National Academies Press. doi: 10.17226/10947.
×

Differential Global Positioning System (DGPS) antenna position relative to the transducer. Higher-frequency echosounders provide higher resolution but have less depth range. Narrower transducer beam widths also improve accuracy. A single-beam survey results in a single line of bathymetric data points along the survey vessel’s track. Historically, most bathymetric data were collected using lead lines or single-beam echosounders. Because survey track lines were generally far apart, obstructions or seafloor irregularities between track lines could remain undetected.

1.2 MULTIBEAM ECHOSOUNDER

Over the past decade, multibeam echosounders have increasingly replaced single-beam echosounders as the preferred tool for comprehensive bathymetric surveys. Multibeam systems are capable of measuring a number of high-resolution depths across a wide corridor as the survey vessel transits. For example, some multibeam echosounders can gather more than 250 soundings across a swath up to seven times the water depth (swath bathymetry). If the swaths from adjacent survey lines overlap, the multibeam echosounder can produce full bottom coverage during a bathymetric survey. Because multibeam systems measure an angular sector originating at the transducer on the ship’s hull, they are more efficient in deeper water.

The data are corrected for heave, pitch, roll, squat, tide, and DGPS antenna offset relative to the transducer. Acoustic sound velocity profiles

Suggested Citation:"2 Coastal Mapping Needs and Activities." National Research Council. 2004. A Geospatial Framework for the Coastal Zone: National Needs for Coastal Mapping and Charting. Washington, DC: The National Academies Press. doi: 10.17226/10947.
×

The coastal zone is dynamic. Storms, vegetation and drainage basin changes, development, sea level rise, tides, wave actions, and currents alter the coastal zone over time. Consequently, repeat measurements of reference frame and source data, together with time series of the derived products, are a critical requirement for understanding and managing the coastal zone.

COASTAL ISSUES REQUIRING GEOSPATIAL DATA AND PRODUCTS

Appendix A summarizes, on an agency-by-agency basis, the needs and activities of the agencies involved in coastal zone mapping and charting. This section recasts those needs and activities within a framework of the seven major themes that capture the fundamental raison d’etre for most coastal zone mapping and charting activities. Collectively, these themes encompass most issues involved in coastal zone management and planning:

  • Navigation

  • Homeland Security

  • Coastal Zone Boundaries

  • Environmental and Living Resource Management

  • Coastal Hazards

  • Minerals and Energy Management

  • Cultural Resource Management

Navigation

Information and products for safe and efficient navigation are fundamental to the maritime interests of any coastal nation. Providing safe and efficient navigation generates a sizeable economic benefit, is a cornerstone for sustainable development, avoids or mitigates environmental catastrophes, and contributes to the quality of life. Because safe and efficient navigation forms the foundation for such a broad range of economic, environmental, and recreational activities, maritime nations have historically undertaken the tasks of collecting, producing, disseminating, and maintaining the necessary navigational data, products, and services within their own waters as a service available to all users at modest cost. In addition, a number of maritime nations with historically global interests have sought to ensure safety of navigation for their merchant and military fleets wherever they may be called on to operate. International organizations and conventions are devoted to furthering safe and efficient navigation

Suggested Citation:"2 Coastal Mapping Needs and Activities." National Research Council. 2004. A Geospatial Framework for the Coastal Zone: National Needs for Coastal Mapping and Charting. Washington, DC: The National Academies Press. doi: 10.17226/10947.
×

are also measured and integrated into the solution for high-accuracy results. Like single-beam echosounders, higher frequencies have higher resolution but are limited to more shallow water. Lower frequencies can sound, with less accuracy, to full ocean depth.

In addition to bathymetry, many multibeam echosounders can also simultaneously measure the magnitude of the reflected signal, which results in colocated backscatter (or multibeam) imagery. Because hard or rough seabed reflects more energy than soft or smooth seabed, multibeam imagery can be used for habitat and sediment mapping. The combination of multibeam echosounder with GPS produces bathymetry and imagery data that are accurately positioned, so that three-dimensional computer-generated digital terrain models (bathymetry) can be draped with the accompanying imagery to depict seabed morphology as well as the nature of sediments. By combining datasets in this way, features can be more easily detected, such as rock outcrops, channels, and small-scale bedforms.

Multibeam data collected by USGS from San Francisco Bay combined with USGS topographic data. New visualization techniques allow such complex environments to be interactively explored in ways that are both intuitive and quantitative. SOURCE: Image courtesy of the Center for Coastal and Ocean Mapping, University of New Hampshire; used with permission.

Suggested Citation:"2 Coastal Mapping Needs and Activities." National Research Council. 2004. A Geospatial Framework for the Coastal Zone: National Needs for Coastal Mapping and Charting. Washington, DC: The National Academies Press. doi: 10.17226/10947.
×

through increased geographic coverage and improved quality of service (IHB, 2001).

Economic Importance of Shipping

As noted earlier, over 98 percent of the nation’s non-NAFTA trade is carried by ships through the U.S. coastal zone. With access to adequate charts of the coastal zone, ships can ply the optimum routes, which in most cases are the shortest navigable routes. In other cases, an optimum shipping route may be longer but traverse a deep water approach that allows larger, fully loaded ships to proceed to port. By coupling high-resolution hydrographic surveys, accurate tidal monitoring and modeling, and dynamic ship response predictors, the minimum under keel clearance can be actively managed to maximize the loading of large commercial vessels (see Box 2.2). Additionally, accurate and up-to-date charts and navigation services should ultimately reduce insurance premiums, as reduced navigation-related incidents are factored into premium calculations. In sum, the advantages of accurate and complete navigational information yield maximum throughput of cargo at the lowest possible costs.

BOX 2.2
Dynamic Under Keel Clearance Management

In most cargo ports the maximum loading of vessels is determined using a conservative consideration of numerous factors, together with the errors associated with the prediction or estimation of these factors. These factors include bathymetry, tides, ocean swell, water density, and the squat, pitch, roll, and heave of a vessel underway in a channel. If greater precision can be achieved in the measurement or prediction of these factors, the cumulative safety allowance can be reduced and vessel loading maximized. Accurate hydrographic surveys are essential for determining bathymetry and the nature of the water bottom, and for improving the dynamic modeling of tides, ocean waves, and the dynamic response of a ship transiting the channel. Several Australian ports actively manage the maximum loading of cargo ships through real-time ocean swell monitoring, accurate tidal modeling, high-resolution hydrographic surveys, and ship response modeling. The economic impact is impressive. For the 1996-1997 fiscal year in Hay Point/Dalrymple Bay, Queensland, 123 vessels loaded nearly an additional 0.75 million tons of coal. The savings in freight cost was $7.5 million, and the increased value of exported earnings was $30 million (O’Brien, 1997).

Suggested Citation:"2 Coastal Mapping Needs and Activities." National Research Council. 2004. A Geospatial Framework for the Coastal Zone: National Needs for Coastal Mapping and Charting. Washington, DC: The National Academies Press. doi: 10.17226/10947.
×

1.3 ACOUSTIC SEABED CHARACTERIZATION

Single-beam echosounders have been used increasingly over the past decade not only to collect bathymetry but also to determine seabed characteristics. One such system is used by ecologists to characterize habitats in shallow waters (1.4 to 30 meters), where it can work effectively at vessel speeds of 8 to 12 knots. The first and second (multiple) echoes returned to the seabed characterization system’s sensor provide indications of the bottom roughness and hardness, respectively. By examining the information from both types of returns, sediment type can be characterized as long as calibration protocols are closely followed. One of the advantages is that the data can be monitored in real time and thus calibrated for a local environment. The disadvantages are that it is not effective in very shallow water (less than 1.4 m) and its narrow coverage may not be suitable for interpolation in areas with patchy distribution of sediment types. These systems typically require local calibration against known bottom types for optimal performance.

1.4 SIDESCAN SONARS

Sidescan sonars use the acoustic energy returned laterally from the seafloor. There are many types of sidescan sonars, and each has its advantages and disadvantages.

Conventional Sidescan Sonar. Sidescan sonars can be used to make digital acoustic images of the seabed. Although most sidescan units are towed behind a survey vessel, they can also be hard mounted to the vessel for very shallow work. The figure shows a towed sidescan sonar that is “looking” out across the seafloor to either side of the ship. Sidescan sonars typically gather imagery with higher resolution than multibeam echosounders, and over a broader swath width. Because they are towed close to the seabed, sidescan sonars can also better delineate seabed obstructions such as rock outcrops, wrecks, and debris. The seafloor is typically surveyed in swaths 100 to 500 meters wide; digital splicing of adjacent sonar lines can be employed to assemble a sidescan sonar mosaic that provides continuous imaging of a mapping area. Like multibeam imagery, digital

Suggested Citation:"2 Coastal Mapping Needs and Activities." National Research Council. 2004. A Geospatial Framework for the Coastal Zone: National Needs for Coastal Mapping and Charting. Washington, DC: The National Academies Press. doi: 10.17226/10947.
×
Navigation Safety

A thorough understanding and charting of the nearshore zone contributes to a reduction in maritime accidents and aids in the mitigation of accidents should they occur. It is self-evident that properly navigated ships using accurate charts will avoid groundings, with their associated risk of oil and hazardous cargo spillage and the potential for destruction of sensitive marine habitats. There are several additional services required for safe and efficient navigation that further prevent or mitigate environmental catastrophes. A maritime information system that monitors changes in the maritime environment and provides mariners with reports of conditions that affect their operations is integral to providing safe and efficient navigation. Local Notice to Mariners (LNM) provides frequent updates to navigational products, with information regarding hazardous conditions such as inoperative navigational aids, wrecks, dredging operations, and military exercises. The World Wide Navigational Warning System (WWNWS) provides navigational and meteorological warnings and other urgent safety-related messages via radio and satellite communications. Maintaining the currency of navigational information, broadcasting emergent safety information, and providing a 24-hour network for mariners to report incidents and unsafe conditions all markedly contribute to the avoidance of maritime accidents and to rapid response when they do occur.

Navigation safety is of concern for recreational boats as well as large vessels. Annual USCG statistics for recreational boating accidents show that there are approximately 500 groundings and 200 additional incidents of “striking submerged objects” each year. Together, these accidents result in more than 300 injuries and deaths annually and millions of dollars in property damage. Because these statistics do not include similar accidents involving nonrecreational vessels such as commercial fishing boats, oilfield supply vessels, and the academic fleet, the true annual cost of property damage is probably substantially greater than that for recreational boats alone. Although some proportion of the costs results from human error, there is undoubtedly a significant proportion that results either directly from inadequate charts or indirectly from reduced situational awareness that could be rectified with modern electronic chart displays.

With the increased availability and decreased cost of GPS receivers, recreational boaters can now receive accurate position data, and many GPS receivers integrate position data with chart data for easy viewing. Unfortunately, the chart data may not be particularly current and therefore may no longer represent the geographic regions accurately. This, together with the enormous variety of areas in which recreational boaters

Suggested Citation:"2 Coastal Mapping Needs and Activities." National Research Council. 2004. A Geospatial Framework for the Coastal Zone: National Needs for Coastal Mapping and Charting. Washington, DC: The National Academies Press. doi: 10.17226/10947.
×

sidescan sonar mosaic images can be draped over a digital terrain model. NOAA often uses a combination of multibeam echosounders and sidescan sonar for nautical charting surveys.

The intensity of sound received by the sidescan sonar tow vehicle from the seafloor (backscatter) provides information on the general distribution and characteristics of surficial sediment. In the lower schematic, strong reflections (high backscatter) from boulders, gravel, and vertical features facing the sonar transducers are white; weak reflections (low backscatter) from finer sediments or shadows behind positive topographic features are black.

Chirp Sidescan Sonar. A technical advance from the conventional sidescan sonar is the chirp sidescan sonar. While conventional sidescan sonars transmit a single frequency (typically 100 or 500 kHz), chirp sidescan sonars transmit a range of frequencies (e.g., 114 to 126 kHz). Through its ability to transmit more energy into the water and the employment of pulse compression techniques, chirp sidescan provides improved target or feature resolution.

High-Speed Sidescan Sonar. Sidescan sonars are generally towed at speeds ranging from 2 to 5 knots. Faster tow speeds result in sonar image blurring because consecutive sonar image lines are too far apart. This effect would be similar to a television that displays only a fraction of the usual number of lines on the screen. However, a new high-speed sidescan can be towed at speeds up to 10 knots, because multiple image lines are recorded in a single transmission. These higher-speed sonars have significantly improved the productivity of surveys in less than 100 meters of water.

Synthetic Aperture Sonar. Another technical advance for sidescan sonars is the newly available synthetic aperture sonar. Synthetic aperture sonar allows consecutive overlapping sonar images to be intelligently stacked

Suggested Citation:"2 Coastal Mapping Needs and Activities." National Research Council. 2004. A Geospatial Framework for the Coastal Zone: National Needs for Coastal Mapping and Charting. Washington, DC: The National Academies Press. doi: 10.17226/10947.
×

travel, has increased the demand for more current and accurate navigational charts (in both paper and electronic formats).

The International Maritime Organization (IMO), a specialized body of the United Nations of which the United States is a signatory Contracting Government, explicitly described the governmental obligation to provide for safe and efficient navigation in the Safety of Life at Sea (SOLAS) Convention (see Box 2.3).

The Marine Navigation Safety Coalition is a marine industry stakeholder group that includes more than 60 organizations, including port authorities, port associations, shipping associations, pilot associations, cruise lines, insurance companies, marine exchanges, and other private corporations. For each of the past several years, the coalition has encouraged NOAA and Congress to more aggressively address the survey back-

BOX 2.3
Regulation 9 of Chapter V of the Safety of Life at Sea (SOLAS) Convention

1. Contracting Governments undertake to arrange for the collection and compilation of hydrographic data and the publication, dissemination, and keeping up to date of all nautical information necessary for safe navigation.

2. In particular, Contracting Governments undertake to co-operate in carrying out, as far as possible, the following nautical and hydrographic services, in the manner most suitable for the purpose of aiding navigation:

2.1 To ensure that hydrographic surveying is carried out, as far as possible, adequate to the requirements of safe navigation;

2.2 To prepare and issue official nautical charts, sailing directions, lists of lights, tide tables and other official nautical publications, where applicable, satisfying the needs of safe navigation;

2.3 To promulgate notices to mariners in order to keep official nautical charts and publications, as far as possible, up to date;

2.4 To provide data management arrangements to support these services.

3. Contracting Governments undertake to ensure the greatest uniformity in charts and nautical publications and to take into account, whenever possible, the relevant international resolutions and recommendations.

4. Contracting Governments undertake to co-ordinate their activities to the greatest possible degree in order to ensure that hydrographic and nautical information is made available on a worldwide scale as timely, reliably and unambiguously as possible.

Suggested Citation:"2 Coastal Mapping Needs and Activities." National Research Council. 2004. A Geospatial Framework for the Coastal Zone: National Needs for Coastal Mapping and Charting. Washington, DC: The National Academies Press. doi: 10.17226/10947.
×

(added together), thereby minimizing random noise while enhancing the image. This technology will allow a 10-fold increase in sidescan sonar resolution, from 1-meter pixel size to 5 centimeters or better across the full sonar swath. This also means that the volume of collected data will increase by more than 100-fold.

Interferometric Sonar. Interferometric sonars are designed to gather both sidescan imagery and swath bathymetry. Interferometric techniques have been tried for many decades with varying degrees of success. In general, they provide excellent sonar imagery but reduced quality of bathymetry, although new developments in sonar design and signal processing are improving the quality of interferometric bathymetric data. These improved versions are of particular interest for coastal mapping work because of their ability to achieve very wide swaths in relatively shallow water.

1.5 SUBBOTTOM PROFILER

Subbottom profilers use reflected sound (similar to the way an ultrasound provides images of internal organs) to provide acoustic (seismic) profiles, or cross sections, of features below the ocean floor. Subbottom systems operate at lower frequencies than echosounders and imaging sonars. High-resolution subbottom profilers operate at the high end of the frequency range (e.g., 3.5 kHz) but do not penetrate very far into the seafloor. Midrange systems (boomers, etc.) collect geophysical information to depths of 80 to 100 meters beneath the ocean floor but provide less detail. Very low frequency seismic systems (air and water guns) are used to profile much deeper into the subsurface (with a further loss of resolution); these are the standard hydrocarbon exploration tool. Subbottom profilers often achieve limited penetration in hard-bottom areas (sand, rocks, etc.) and areas where shallow methane gas has accumulated.

2. OTHER UNDERWATER SENSORS

Other underwater sensors include magnetic systems and light-based systems (e.g., cameras and lasers). Some of these have been in use for many

Suggested Citation:"2 Coastal Mapping Needs and Activities." National Research Council. 2004. A Geospatial Framework for the Coastal Zone: National Needs for Coastal Mapping and Charting. Washington, DC: The National Academies Press. doi: 10.17226/10947.
×

log (estimated in 2000 to be 43,000 square nautical miles for “critical” areas and 491,000 square nautical miles for “significant” areas; DeBow et al., 2000) and associated tidal monitoring programs. This group maintains that such programs are critical for safety of life and the protection of property and the environment as well as for improving the efficiency and competitiveness of the U.S. marine transportation system.

Collection and Processing of Source Data for Navigation

For U.S. waters the Office of Coast Survey (OCS), an office of NOAA’s National Ocean Service (NOS), collects and processes the vast majority of data necessary for navigation. OCS vessels, or private industry ships contracted by OCS, collect hydrographic data that include bathymetry, tides, water column properties, and bottom composition. Nearly 50 percent of the data compiled by OCS are obtained through contract to private industry. Aids to Navigation (AtNs) are initially fixed during these surveys; however, USCG normally maintains these aids and provides updated status and position to OCS as conditions warrant.

The National Geodetic Survey (NGS) provides delineation of the nation’s shoreline using numerous techniques, including airborne photogrammetry, satellite altimetry, LIDAR, and land-based survey. Data collection performed at low tide may also be useful for detecting shallow-water hazards.

The U.S. Army Corps of Engineers (USACE) is tasked to monitor and maintain the navigability of numerous harbors and inland waterways. Additionally, the USACE undertakes beach replenishment projects, requiring an understanding of sediment transport processes and the identification of sediment sources. Each of these activities requires the collection of bathymetry, bottom composition, and coastal topography, although in some instances the data collection may not meet international standards for nautical charts.

The U.S. Navy collects and processes hydrographic data outside the nation’s territorial waters. These data are provided to the National Geospatial-Intelligence Agency (NGA; formerly the National Imagery and Mapping Agency) for compilation into the nautical charts and products that are used for U.S. and allied military operations. Since September 11, 2001, the U.S. Naval Oceanographic Office has collaborated with OCS in the collection of bathymetric and sidescan sonar data in strategic U.S. harbors (see Homeland Security section below).

The USCG installs and maintains AtNs throughout U.S. waters, and the precise positions of these AtNs are provided to NOS and NGA for inclusion in nautical charts and publications. Changes in the status or characteristics of AtNs and the existence of hazardous conditions are

Suggested Citation:"2 Coastal Mapping Needs and Activities." National Research Council. 2004. A Geospatial Framework for the Coastal Zone: National Needs for Coastal Mapping and Charting. Washington, DC: The National Academies Press. doi: 10.17226/10947.
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years, while others are more recent developments; all of these technologies, however, are experiencing continual improvements in hardware, software, and data presentation.

2.1 MAGNETOMETER

The marine magnetometer measures the earth’s magnetic field and is normally towed from a vessel in a manner similar to the sidescan sonar. Ferrous objects, such as pipelines, sunken vessels, and metal debris, will affect the ambient magnetic field measured by the magnetometer. These effects, or anomalies, provide indications of the presence of features that are not apparent from data provided by acoustic sensors. The magnetometer is particularly useful for locating buried or subtle ferrous objects.

2.2 GRADIOMETER

Gradiometers are actually comprised of two magnetometers, whose solutions are combined to reduce the effects of ambient ferrous, or magnetic, noise. They are of particular value when trying to identify small ferrous objects that are within the magnetic field of larger ferrous objects. An example would be locating individual items within a debris field.

2.3 LASER LINE SCAN

Laser line scanning systems are towed or mounted on a sled and moved in a slow constant fashion at a stable height over the seafloor. As the sled moves forward, a narrow laser beam incrementally scans a portion of the seafloor. Individual scans are combined to create very detailed images with a quality that approaches that of a conventional photograph. Accurate positioning determinations are critical for assembling continuous mosaic coverage of a mapped area. One advantage of this laser technique is the ability to obtain

Suggested Citation:"2 Coastal Mapping Needs and Activities." National Research Council. 2004. A Geospatial Framework for the Coastal Zone: National Needs for Coastal Mapping and Charting. Washington, DC: The National Academies Press. doi: 10.17226/10947.
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monitored by the USCG and reported through LNMs and provided to NGA for worldwide distribution. Recreational boaters, through the activities of the U.S. Power Squadron and the USCG Auxiliary, provide a valuable quality assurance function and source of input for LNMs.

NGA does not generally collect source data, relying on the U.S. Navy and exchange agreements with other nations; however, the agency partnered with the National Aeronautics and Space Administration (NASA) on the Shuttle Radar Topography Mission (SRTM) that collected high-resolution radar altimetry data for over 80 percent of the earth’s land topography. These data are sufficiently accurate to position a non-tidally corrected coastline. Additionally, NGA accesses commercial and intelligence satellites capable of providing topography and land-use information; however, the collection of this information is generally restricted to foreign land, and the resulting products are frequently classified.

NGA, NOAA-OCS, USACE, and the Navy access satellite imagery operated by other government agencies (NOAA’s National Environmental Satellite, Data, and Information Service [NESDIS], National Reconnaissance Office) or commercial activities (IKONOS, LANDSAT, SPOT, etc.). Historical information regarding coastal processes is accessed through archives held by state and local governments and academia.

Tools and Applications for Using Navigation Data

The various agencies use different tools and applications to process, disseminate, and display their hydrographic data. NOAA’s CSC Web site4 offers access to GIS tools for accessing rasterized navigation charts, and NOAA’s National Geophysical Data Center (NGDC) Geophysical Data System (GEODAS) software offers access to point data in a more basic form. NGA and the Navy developed the Hydrographic Source and Assessment Systems (HYSAS) protocol for the transfer, assessment, and manipulation of data between these two agencies, and other agencies have similar programs tailored to their individual needs. USACE’s Scanning Hydrographic Operational Airborne LIDAR Survey (SHOALS) ToolBox provides applications for the manipulation of geospatial data and engineering calculations. A wide range of private-sector electronic chart products (some supported by officially sanctioned databases) offering both raster and vector products exist (e.g., Electronic Chart Display and Information Systems [ECDIS], Ward et al., 2000).

Suggested Citation:"2 Coastal Mapping Needs and Activities." National Research Council. 2004. A Geospatial Framework for the Coastal Zone: National Needs for Coastal Mapping and Charting. Washington, DC: The National Academies Press. doi: 10.17226/10947.
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a relatively clear image at three times the range of an underwater camera. However, because of their cost and complexity, laser line scan systems are in limited use.

2.4 PHOTOGRAPHY/VIDEOGRAPHY

Underwater video and photography can be effective methods for obtaining marine data. Photographs and video stills can be used in conjunction with image analysis software to determine the coverage and character of submerged vegetation or bottom sediments and the density and health of epibenthic (seafloor surface-dwelling organisms) species. Like other visual techniques, the quality of video or photo data is negatively affected by turbid water, and ranges are typically quite limited.

2.5 SEDIMENT PROFILING IMAGERY

Sediment profiling systems are specially designed cameras and frames with a wedge-shaped prism mounted to penetrate the seafloor. The weight of the whole apparatus drives the prism into the sediment and the rate of descent is controlled by oil-filled pistons. One side of the wedge is plexiglass, and the whole prism is filled with distilled water. Turbidity of the water does not interfere with the image quality because the plexiglass is directly in contact with the sediment. A mirror on the back of the prism reflects the sediment profile up to a camera that is mounted above the prism. The prism penetrates up to 20 centimeters of sediment, and the image has a resolution of approximately 0.06 millimeters.

One disadvantage of the sediment profile system is that a rough characterization of the bottom type is required before deployment to avoid rocky areas. Like other point sampling techniques, many samples may be required to characterize a habitat using a sediment profile imagery system, especially if there is high variability on a small spatial scale. However, when combined with other technology such as a multibeam echosounder or sidescan sonar, this equipment can produce highly detailed habitat characterization.

Suggested Citation:"2 Coastal Mapping Needs and Activities." National Research Council. 2004. A Geospatial Framework for the Coastal Zone: National Needs for Coastal Mapping and Charting. Washington, DC: The National Academies Press. doi: 10.17226/10947.
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Navigation Products

Numerous safety-of-navigation products are compiled directly from source data. The purest examples are databases accessible in hard copy or digitally through the Internet, such as LNMs, Lists of Lights, AtNs, and Radio Navigation Aids. These products are produced locally by USCG and on a worldwide basis by NGA. More complex products are produced through the combination of several data sources. The World Vector Shoreline produced by NGA is an example of a database populated from a variety of sources. On the extreme end of complexity, a nautical chart is the depiction of numerous datasets, such as bathymetry, AtNs, bottom composition, and water column properties. As noted above, nautical charts are produced by OCS for U.S. waters and globally by NGA. Similarly, USACE produces several products based on source data collected for the waterway projects for which the agency is responsible. Typical USACE products include inland waterway charts, both hard-copy and electronic, navigation channel condition reports, and engineering drawings of waterway projects. The fact that the above products flow directly from source data does not imply an automated process. Since these products are directly related to safety of navigation, there are extensive quality control, validation, and verification components associated with their generation.

The combination of disparate datasets, modeled parameters, and rule-based assumptions is the basis for derived map products for the navigator, such as NGA’s Sailing Directions, Pilot Charts, and Port Directories, as well as general navigation reference documents such as The American Practical Navigator, sight reduction tables, and nautical almanacs.

Homeland Security

The physical security of U.S. ports is a mission of the USCG in general and the U.S. Navy for selected ports. Following the terrorist attacks of September 11, 2001, homeland security has become a priority national concern, with port security being a significant focus. Coastal mapping and charting are integral elements of several components of homeland security. In particular, the mining of a port, the intrusion into the port by swimmers or underwater vehicles, or the release of chemical or biological agents into the water are all potential threats. An adequate knowledge of the nation’s ports and surrounding coastal areas is a necessary requirement for defending against or responding to such terrorist attacks.

Counter Mine Warfare (CMW) requires high resolution bathymetry and backscatter data for entire ports and shipping sortie routes out to deep water in advance of any threat. These data are used to identify and precisely fix all objects on the bottom that may appear mine-like. In the

Suggested Citation:"2 Coastal Mapping Needs and Activities." National Research Council. 2004. A Geospatial Framework for the Coastal Zone: National Needs for Coastal Mapping and Charting. Washington, DC: The National Academies Press. doi: 10.17226/10947.
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3. REMOTE SENSING FROM AIR AND SPACE

Concomitant with the rapid evolution of sonar technology have been revolutionary changes in the spatial and spectral capabilities of imagery collected from air or space. Remote sensing from the air offers the distinct advantage of high productivity through large areal coverage. On the other hand, it is often constrained by weather, visibility, and sun angle. Optical remote sensing techniques rarely penetrate through the water column but can provide extremely valuable data to describe the terrestrial component of the coastal zone, as well as water quality conditions, sediment transport, surface water temperature, and organic productivity.

3.1 AERIAL AND SATELLITE IMAGERY

Photography from aircraft can be accomplished with conventional film or digital technology. Digital images have the advantage of being viewable in the field, allowing immediate verification of image quality. Positional information is generally recorded concurrently using GPS and Inertial Measurement Unit (IMU) instruments. Disadvantages of aerial photography include difficulties in the timing of flights to coincide with low tide, vegetative cover, and acceptable weather conditions. With adequate ground truthing, aerial photography can be orthographically rectified (or orthorectified), so that the image (an “orthoimage”) can be scaled in both directions. If the aerial imagery has adequate overlap, three-dimensional data can be generated.

Satellite imaging systems such as Landsat and the Advanced Very High Resolution Radiometer (AVHRR) provide even wider coverage, with multispectral information useful for sensing objects in the onshore and very shallowest offshore components of the coastal zone. Although the resolution of these sensors has been limited to tens of meters up to a few kilometers, recent improvements in high-resolution satellite imaging (e.g., IKONOS and QuickBird) have created the potential for employing satellite images in coastal zone applications that previously have been supported only by aerial photographs. Satellite imagery has the advantage of systematic coverage, periodic observations for both short- and long-term change detection, and potentially better cost effectiveness. The committee anticipates increased use of satellite images in coastal applications in the future. Unfortunately, satellite-based imaging capabilities degrade rapidly as water depth increases. Although the bathymetry of deep-ocean basins may be considerably improved using satellite-based radar altimetry (Sandwell et al., 2002), the limited resolution available using this technique in shallow coastal waters offers little potential for replacing acoustic bathymetric measurements.

Suggested Citation:"2 Coastal Mapping Needs and Activities." National Research Council. 2004. A Geospatial Framework for the Coastal Zone: National Needs for Coastal Mapping and Charting. Washington, DC: The National Academies Press. doi: 10.17226/10947.
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event that a harbor is mined, change detection algorithms are used to discriminate between the previously mapped mine-like objects and new objects detected by post-mining surveys. Bottom characterization using acoustic methods and grab or core samples is necessary to determine the likelihood of mine burial, and accurate current and circulation models are necessary to predict the trajectory of floating mines. Additionally, description of the local magnetic field variability is required to defend against magnetic influence mines. CMW efforts typically produce “Q-Route” charts5 that lay out predetermined sortie routes, which can be easily cleared of mines because they have few existing mine-like objects and have bottom characteristics that would ease the detection and removal of mines. The various factors affecting CMW are assembled in classified Mine Pilot Publications for each port of interest.

Visual detection and acoustic detection are the primary methods used to counter the intrusion of swimmers or underwater vehicles. Acoustic detection in shallow water is difficult, but is more easily accomplished with a combination of high resolution bathymetry and bottom and water column characterization that relates to sound propagation. High-resolution bathymetry is pivotal to improved tidal and current models that are important components in understanding waterborne intrusion routes. In the event of a release of chemical or biological agents into the water, high-resolution bathymetry, bottom characterization, and tidal and current modeling are critical for understanding the propagation of these agents and their interaction with bottom sediment.

The U.S. Navy has collected data necessary for port security and Q-Route determination for certain strategic naval ports. Post-9/11 activities in support of homeland security demonstrate several examples of improved communication and cooperation between agencies. With the need to expeditiously collect data, NOAA, Navy, USCG, and USACE have routinely met and assigned data collection responsibilities against a prioritized list of requirements. This list typically includes 100 percent coverage of designated port areas for a range of data—high-resolution bathymetry, acoustic bottom backscatter, sea bottom characterization, fixing of mine-like objects, tides, currents, physical properties of the water column, and magnetic variability.

Coastal Zone Boundaries

Boundaries in the coastal zone are linear features defined for a range of purposes, including the establishment of national, international, and

5  

The U.S. Navy refers to shipping lanes in mined or potentially mined waters as “Q-routes” (see NRC, 2003c).

Suggested Citation:"2 Coastal Mapping Needs and Activities." National Research Council. 2004. A Geospatial Framework for the Coastal Zone: National Needs for Coastal Mapping and Charting. Washington, DC: The National Academies Press. doi: 10.17226/10947.
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Hyperspectral imaging instruments can collect spectral reflectance data in shallow water or over land. The sensors are mounted on small aircraft and detect reflectance up to 288 narrowband wavelengths in the visible and infrared spectrum. The user can specify which spectral bands are measured and the bandwidths that are used. GPS coordinates and altitude are recorded along with the reflectance data. The data produced by hyperspectral imaging achieve very high resolution but require special image-processing software for importation into GIS. Like all aircraft-mounted technologies, hyperspectral sensors require clear, calm, shallow water to obtain high-quality data offshore. Variable water chemistry and tidal or solar conditions can alter the spectral signal of particular bottom features, and therefore a highly trained observer is required to interpret the data.

The Compact Airborne Spectrographic Imager (CASI) was the first commercially available hyperspectral sensor. The information gathered by CASI systems can be used for mapping bathymetry and habitat in shallow water. CASI can also be used to assess some water quality parameters such as the presence of algae that are associated with Harmful Algal Blooms (HABs; e.g., red tides).

3.2 TOPOGRAPHIC LIDAR

This equipment measures the distance between the ground and an aircraft using laser light. LIDAR sends a short laser pulse, and the elapsed time for the signal to be reflected from the ground to the airborne receiver is recorded. Because the laser scans across track, topographic data are collected across a wide corridor as the survey proceeds. Highly accurate topographic maps (up to 20 centimeters vertical resolution) can be made using LIDAR in sandy areas, but this technology is not as effective in rocky habitats. The strength of the return signal provides additional information about the target.

In contrast to bathymetric LIDAR, where federal agencies are providing the substantial investment needed for initial technology development, topographic LIDAR is a relatively mature technology that is now dominated by the private sector, with numerous companies offering commercial LIDAR services.b

3.5 BATHYMETRIC LIDAR

Bathymetric LIDAR works like a multibeam echosounder but using light instead of sound. It can determine depths across a swath width of 220 meters when flown at an altitude of 400 meters. Data densities of 2 meters × 2 meters have been achieved, with a depth resolution to 15 centimeters. In clear water, bathymetric LIDAR is far more productive than ship-based

Suggested Citation:"2 Coastal Mapping Needs and Activities." National Research Council. 2004. A Geospatial Framework for the Coastal Zone: National Needs for Coastal Mapping and Charting. Washington, DC: The National Academies Press. doi: 10.17226/10947.
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local jurisdictions (territorial claims and property lines), hazard studies, and long-term environmental management. In many cases, coastal zone boundaries represent the convergence of law and spatial mapping. Both marine and onshore boundaries share the concept of “cadastre” in that they have components of adjudication, survey, and owner rights but differ in that the common land-based process of demarcation is not usually applied to marine boundaries. Instead marine boundaries are typically delimited mathematically, with no physical evidence like monuments or pins present (Fowler and Treml, 2001). Marine boundaries often define the initial starting points for many critical legal issues and process studies, but because of the dynamic nature of the coastal environment, these boundaries may change over time. Timely and routine mapping and updating of these boundaries are thus extremely important for safe navigation, resource management (e.g., Thormahlen, 1999), environmental monitoring, coastal development, and many other applications.

The Shoreline

Many coastal zone boundaries are described relative to the dynamic shoreline. Because the shoreline is not static and its location at any point in time is affected by tides, a discussion of shoreline mapping (and most other marine boundary mapping) cannot be separated from discussion of tidal datums. A tidal datum is a base elevation used as a reference from which to measure heights or depths that are defined with respect to a certain phase of the tide (Hicks et al., 2000). A number of tidal datums are used in chart making—in the United States, the common datums are Mean Higher High Water (MHHW), Mean High Water (MHW), Mean Low Water (MLW), Mean Lower Low Water (MLLW), and Mean Sea Level (MSL). To establish an official tidal datum, tide measurements are made over a period of 19 years—the National Tidal Data Epoch (NTDE). The datum used—for example, MLW—is thus the average of all of the MLWs over a 19-year period. The 19-year average is used because it represents the Metonic cycle that accounts for the full range of distances between the earth, the sun, and the moon. The NTDE is reviewed annually for revision and must be reconsidered every 25 years (Hicks et al., 2000). Depending on which datum is used, the position of the “shoreline” or land-water interface on a map will be different, with significant impact on the determination of maritime boundaries (see Figure 2.1).

Figure 2.1 illustrates the multiple definitions of the shoreline and submerged lands that are used by different federal, state, and local authorities. Twenty-one states define the state submerged land boundaries based on the tide-coordinated shorelines (MHW and MLLW), and the Exclusive Economic Zone (EEZ) boundary is determined based on the MLLW shore-

Suggested Citation:"2 Coastal Mapping Needs and Activities." National Research Council. 2004. A Geospatial Framework for the Coastal Zone: National Needs for Coastal Mapping and Charting. Washington, DC: The National Academies Press. doi: 10.17226/10947.
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multibeam echosounders. Bathymetric LIDAR uses red and green lasers to determine water depth. Both signals are transmitted simultaneously, but the red is reflected at the water surface while the green laser is reflected from the ocean bottom. The time difference between the two returned signals is used to determine the depths. Bathymetric LIDAR is limited to three times secchi depth (about three times the visibility range), resulting in a typical maximum depth capability of 20 to 30 meters, and bathymetric LIDAR can never achieve the spatial resolution of multibeam echosounders because the laser beam spreads to approximately one-half the water depth upon entering the water. Nonetheless, bathymetric LIDAR and ship-based multibeam echosounders are complementary; clear, very shallow water is best surveyed with LIDAR, whereas more turbid waters are best surveyed with multibeam echosounders.

4. DIRECT SAMPLING

Remotely sensed data, such as sidescan imagery, require a certain amount of direct sampling verification to ensure their interpretation is valid. A range of seafloor sampling devices are available for this purpose; two of the more common ones are grab samplers and piston corers.

4.1 GRAB SAMPLER

Grab samplers are often used to ground truth data from remote sensing instruments. A variety of designs are used to obtain sediment samples from the ocean bottom. Generally, grab samplers consist of a clamshell “jaw” that is locked open and lowered to the bottom by a cable. When the grab sampler impacts the bottom, a trigger mechanism allows the jaw to close and take a “bite” out of the bottom. The type of information that can be obtained includes sediment type, sediment quality, organic content, and the density and identification of infauna.

Suggested Citation:"2 Coastal Mapping Needs and Activities." National Research Council. 2004. A Geospatial Framework for the Coastal Zone: National Needs for Coastal Mapping and Charting. Washington, DC: The National Academies Press. doi: 10.17226/10947.
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FIGURE 2.1 Definitions of shorelines by federal and state agencies. Figure courtesy of the Minerals Management Service.

line. Shoreline locations are important to all levels of government operations, coastal policy making, and judicial applications. Private land owners use parcel boundaries for their land ownership. The Federal Emergency Management Agency (FEMA) and insurance companies determine premiums and damage estimates using private land boundaries and shorelines. Any private land lost due to erosion or other reasons becomes state submerged land in many states. Underwater dumping sites and oil and gas lease boundaries are on federal or state submerged lands, which in turn are determined based on the tide-coordinated shoreline.

Compounding the problem of shoreline delineation is the spatial and temporal variability of tides as well as the influence of local winds and weather. The United States maintains a network of only about 140 permanent tidal stations around the coastline. The information from these long-term discrete tidal measurement points (as well as data from shorter-term supplemental tidal stations) is used to build predictive models that allow tidal datums to be determined in the absence of long-term records and

Suggested Citation:"2 Coastal Mapping Needs and Activities." National Research Council. 2004. A Geospatial Framework for the Coastal Zone: National Needs for Coastal Mapping and Charting. Washington, DC: The National Academies Press. doi: 10.17226/10947.
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4.2 PISTON CORER

Like grab sampling, piston core sampling is generally effective only in soft sediment. Under the right seafloor conditions, typical piston corers can provide a few meters of ocean bottom sediment samples. Larger “jumbo” piston coring systems can produce samples up to 30 meters long, and there is one giant piston corer that can penetrate to 60 meters. The coring apparatus is lowered to the bottom and triggered. A weight pushes the core barrel into the seafloor while a piston seal in the barrel causes suction, helping to recover the sediment sample. The piston core technique results in minimal stratigraphic disturbance.

SOURCES: 1.1-single-beam echosounder, image courtesy of the Woods Hole Oceanographic Institution; 1.2-multibeam echosounder, image courtesy of Kongsberg Simrad; 1.3-acoustic seafloor map, image courtesy of Stenmar Sonavision Limited; 1.4-sidescan sonar, image courtesy of USGS Coastal and Marine Geology Program; 1.5-EdgeTech subbottom profiler, image courtesy of EdgeTech Sonar Products; 2.1-Geometrics G-882 magnetometer, image courtesy of Geometrics; 2.3-laser line scan, image courtesy of NOAA Office of Ocean Exploration; 2.5-sediment profile camera deployment, image courtesy of NOAA Coastal Services Center; 3.5-bathymetric LIDAR, image courtesy of Optech, Inc.; 4.2-piston corer, image courtesy of USGS Coastal and Marine Geology Program.

Suggested Citation:"2 Coastal Mapping Needs and Activities." National Research Council. 2004. A Geospatial Framework for the Coastal Zone: National Needs for Coastal Mapping and Charting. Washington, DC: The National Academies Press. doi: 10.17226/10947.
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instantaneous tidal levels to be predicted at locations where tide gauges are not present. Unfortunately, these predictions are often very coarse and inaccurate and are complicated by local topography, wind, and waves. Finally, the process of making bathymetric measurements close to the shoreline is often difficult. As noted above, acoustic techniques for measuring depth are often inaccurate and inefficient in very shallow water, and optical techniques (e.g., LIDAR) are often foiled by poor visibility in the surf zone.

The ubiquitous need for defining the shoreline as a critical reference point for a range of jurisdictional, scientific, and management purposes has led to the collection of shoreline data by many agencies using a variety of techniques. Not all techniques take into consideration the effect of tides. For example, the shoreline delineated on USGS topographic maps is derived from stereo aerial photographs without reference to tidal (MHW or MLLW) datums. This results in the establishment of an instantaneous and static shoreline representing the time the aerial photograph was taken. Some states use similar methods but may delineate a shoreline using only a single aerial photograph without rectification. The shoreline on maps developed by the Bureau of Land Management (BLM) is delineated by the approximate seaward limit of land vegetation, as determined by observation and surveying. The shorelines depicted on NOAA nautical charts are defined as the shorelines generated by the intersections between the land and water surfaces of the MHW and MLLW datums. In practice, the shorelines are derived from stereo aerial photographs taken at times when the water level reaches the estimated MHW and MLLW from long-term tide gauge station observations. The NOAA shoreline is the official boundary line recognized by international agencies. EEZ boundaries are defined as boundaries 200 nautical miles from the MLLW shoreline as depicted on NOAA nautical charts.

Ecological and Land-Use Boundaries

Ecological and/or land-use descriptions and boundaries are necessary for effective resource management and coastal planning. At federal and regional levels, land-use boundaries and ecological boundaries in the coastal zone—such as coral reef, wetland, and land-cover (vegetation type) boundaries—are generally derived from LANDSAT satellite images with resolutions of 15 to 30 meters, or from aerial photographs. Similarly, wetland and Submerged Aquatic Vegetation (SAV) boundaries are derived from satellite and aerial photographs. Watershed boundaries on maps produced by FEMA are created from aerial photographs and terrain models. State and local jurisdictions often employ more precise mapping with field verification.

Suggested Citation:"2 Coastal Mapping Needs and Activities." National Research Council. 2004. A Geospatial Framework for the Coastal Zone: National Needs for Coastal Mapping and Charting. Washington, DC: The National Academies Press. doi: 10.17226/10947.
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Administrative and Legal Boundaries

Administrative boundaries such as forest and park boundaries, refuge and preserve boundaries, marine sanctuary and marine protected area boundaries, and oil and gas lease boundaries are often established based on geographic coordinates. Such boundaries are determined based on a variety of fragmented and complex laws, regulations, programs, and special jurisdictions and by a variety of means. Cadastral boundaries are surveyed using both old (surveying) and new technologies (GPS) with different accuracies and often using different coordinate systems.

Often, different boundary definitions of maritime regions are required for different applications. For instance, the MHW shoreline is important for FEMA, where catastrophic flooding is of concern, while the MLLW shoreline is required for producing charts that will ensure safe navigation. In other cases the different definitions have no rationale other than historical precedent.

The problems described above in delineating the shoreline and other coastal boundaries are ubiquitous to all those who need spatial information in the coastal zone—it is a region that is difficult to map, and reference lines, reference frames, and reference points must be established that can be easily updated and transferred among a range of users. Consequently, the user community needs improved means to collect data in the region of the shoreline as well as the means to seamlessly integrate and transform data from disparate sources collected for different purposes.

Environmental and Living Resource Management

Human impacts on coastal ecosystems have expanded faster than the rate of population growth. Increased stress resulting from development, waste disposal, and the lack of adequate planning and controls have all contributed to the degradation, loss, and pollution of coastal wetlands, beaches, dunes, nearshore waters, and estuarine habitats. Information and management tools for stressed coastal areas are needed for wise stewardship and sustainable development. A fundamental requirement is an understanding of coastal habitats and ecosystems, their geographic extents, and the manner in which these habitats are changing through both natural and anthropogenic processes. The key to obtaining this understanding is the collection of appropriate combinations of one-time “snapshots” and routine time-series measurements of a number of geospatial parameters.

Suggested Citation:"2 Coastal Mapping Needs and Activities." National Research Council. 2004. A Geospatial Framework for the Coastal Zone: National Needs for Coastal Mapping and Charting. Washington, DC: The National Academies Press. doi: 10.17226/10947.
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Living Resources and Coastal/Marine Habitats

Geospatial information is required for the management and sustainable use of a broad range of economically important living resources that provide:

  • Income from the harvesting of living resources (fisheries/aquaculture);

  • Habitats that support onshore and nearshore food webs;

  • Opportunities for recreational activities;

  • Biogeochemical functions such as buffering and recycling discharges from land (mud flats, barrier islands, and salt marshes); and

  • Physical protection from storms (e.g., mangroves, coral reefs).

Maps showing the locations and extent of submerged and emergent habitats are an essential requirement for coastal zone planning activities, so that resources can be properly allocated and development planned to minimize negative ecological impact. Habitat mapping—the description of the physical and biological characteristics of an area—is an essential first step toward development of effective protection strategies for endangered and threatened species. The need for coordinated, comprehensive habitat mapping encompasses environments from the terrestrial to the deep ocean:

  • Terrestrial habitats (riparian areas, wetlands, and coastal uplands);

  • Shoreline and emergent habitats (beaches, dunes, marshes, and mangroves);

  • Intertidal habitats, including areas of shellfish concentrations, sand and mud flats, and wash zones;

  • Shallow marine and estuarine habitats requiring significant light levels (shellfish beds, submerged aquatic vegetation, cold water corals, and coral reefs);

  • Identification of essential fish habitat as required by the Magnuson-Stevens Fishery Conservation and Management Act; and

  • Deep-water marine shelf habitats (hard-bottom substrates, deeper-water alga and corals, sand and mud deposits).

The basic source data required to characterize this range of habitats include bathymetry and topography, submerged and emergent geology (including depositional environments and bottom characterization), currents and tidal range, and the submerged and emergent ecology (including the types and distributions of organisms, biological diversity and health, and community structure). The synthesis, display, and utilization of such diverse information components require basemaps that encom-

Suggested Citation:"2 Coastal Mapping Needs and Activities." National Research Council. 2004. A Geospatial Framework for the Coastal Zone: National Needs for Coastal Mapping and Charting. Washington, DC: The National Academies Press. doi: 10.17226/10947.
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pass offshore and onshore regions and are continuous across local, state, or other jurisdictional boundaries.

Since the coastal zone can be subject to rapid changes, time-series data collection at appropriate intervals is necessary. Datasets collected at intervals must be comparable and capable of being geographically coregistered. The specific habitat mapping requirements identified by those agencies charged with assessing and mapping habitats and sensitive areas and by science and coastal manager users, as identified in the NOAA-CSC Coastal Resource Management Customer Survey, are listed in Appendix A.

An ultimate goal would be the establishment of a uniform habitat classification system that could provide the basis for mapping living resources in the coastal zone. The call for a national habitat classification system is one of the recommendations of another NRC report (NRC, 2002), which noted that logical and consistent habitat classification would provide the basis for evaluating the extent and significance of habitat disturbance. While the complex issues of defining a uniform national habitat classification scheme are beyond the scope of this report, collection of the framework and source geospatial data essential for such a system are not.

Sediments

Sediment movement in the coastal zone is often responsible for changes in shoreline position (accretion or erosion), habitat distribution and quality, and bathymetry (deposition and erosion). Such changes are relevant to human occupation of the coastal zone because they alter ports and navigation channels, change the patterns of hazardous coastal flooding, and impact the physical and biological character of coastal areas. Mapping sediment type and tracking sediment movement along the coastal zone—including the mapping of shoals that impact economic commerce—are important responsibilities of the federal government and state governments. Sediment management for the purpose of keeping shipping lanes open is a major task of the USACE.

Sediments also play a critical role with respect to living resources. Sediments moving across and through coastal ecosystems have the potential to benefit or harm living communities. Most ecosystems in the coastal zone rely, to some degree, on a natural substrate. Many species experience substrate-dependent life stages, and their location and settlement on particular substrates are key to their reaching maturity and achieving reproductive success. Other species rely on substrate-specific food sources. As depositional environments and sediment quality change, substrate characteristics are altered, potentially forcing changes in associated ecosystems.

Suggested Citation:"2 Coastal Mapping Needs and Activities." National Research Council. 2004. A Geospatial Framework for the Coastal Zone: National Needs for Coastal Mapping and Charting. Washington, DC: The National Academies Press. doi: 10.17226/10947.
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Certain coastal environments such as beaches, dunes, flats, and wetlands are sediment dependent. For instance, tidal lagoon substrates are populated by sessile filter feeding communities that depend on material flux as a food source. The same communities are vulnerable to excess sediment influx from upland land use related to agriculture or development. Conversely, coastal marshes need sediment input to keep up with sea level rise. Too much upland sediment control and damming of rivers can starve these vital resources of the sediment necessary for their survival. Thorough knowledge of the role that sediments play in supporting various coastal plant and animal communities is crucial to management agencies responsible for regulating sediment flux across the coastal zone from upland sources.

An enormous volume of sediment-related geospatial data is spread throughout government agencies, academic research programs, and the private sector. Much of this information is in the form of benthic surveys that were collected at a variety of scales, using different datums and covering an assortment of areal extents. Additionally, few of these data span the intertidal zone, so that they can be linked to terrestrial geospatial data. Other data were collected for a single purpose and now lie unused and unknown to others.

The dynamic nature of coastal processes and the shifting pathways of coastal sediments require that effective coastal resource agencies and permitting authorities have ready access to timely and accurate sediment flux and distribution information that spans the land-water interface. This information must be easily manipulated, accurately tied to a widely used and recognized datum, and rectified at the submeter scale in three dimensions (cf., NRC, 1990; 1995a).

Water Quality and Pollutants

Healthy habitats and ecosystems have their own strict requirements for water quality. Human usage of coastal areas for food production, recreation, and other activities has water quality implications and requirements. The protection of estuarine and marine water quality from pollutants is a priority of local, state, and federal agencies as well as industry and the public (EPA, 2001). Nutrient enrichment from wastewater treatment plants and runoff leading to eutrophication are growing problems in almost all estuarine systems in the United States (NRC, 2000). Some embayments, and even some open-ocean areas (e.g., portions of the Gulf of Mexico near the outflow of the Mississippi River), are experiencing extreme hypoxia leading to recurring fish kills and habitat loss (e.g., sea grasses, coral reefs). In some areas (e.g., offshore Florida), the degradation of onshore aquifers causes coastal zone pollution when the aquifers

Suggested Citation:"2 Coastal Mapping Needs and Activities." National Research Council. 2004. A Geospatial Framework for the Coastal Zone: National Needs for Coastal Mapping and Charting. Washington, DC: The National Academies Press. doi: 10.17226/10947.
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discharge from offshore freshwater springs. Also of concern to coastal resource managers are the impacts of heavy metals (still discharged in small quantities) on water quality, coastal zone habitats, and benthic and pelagic species.

Resource managers, regulators, and researchers monitor water quality to assess the baseline condition of water bodies, identify impacts of coastal discharges and developments, determine temporal and spatial variability of estuarine and open-ocean systems, and discover violations of water quality standards. From baseline and time-series data, researchers also develop models that can aid in predicting the potential impacts of continued development or the effectiveness of proposed management measures.

In the interest of public health, many states (often with assistance from local governments, beach associations, and environmental groups) monitor the water quality of swimming beaches during the swimming season and make the results available to the public. However, when it comes to a more comprehensive understanding of the status of their coastal waters, relatively few states have the resources to develop long-term comprehensive marine monitoring programs beyond what is required for the protection of public health, National Pollutant Discharge Elimination System (NPDES) permits, or Environmental Protection Agency (EPA) 301 (3)(b) reporting requirements. EPA’s National Coastal Assessment Program is supporting state efforts to develop a national marine monitoring system that meets state-specific needs. This five-year program provides an opportunity for states to design programs and synthesize data for public outreach.

The development of ocean-observing arrays and in-situ buoys is expanding our ability to access real-time water quality data in addition to other oceanographic parameters (e.g., Gulf of Maine Ocean Observing System6). Managers are increasingly looking for ways to spatially depict water quality data, both as management tools and to provide greater public access to the data (EPA, 2001). The multidimensional nature of water quality data complicates the mapping of such data. Water quality data (e.g., dissolved oxygen, total suspended solids, fecal coliform, chlorophyll content) are typically plotted as a function of position and depth. An even greater challenge is to depict water quality data as a function of time (i.e., time-series plots). Because of the continuum of processes—from land-based sources to offshore sinks—water quality maps need to be continuous across the land-sea interface. Intuitive and standardized tools are needed to integrate and display rich thematic water quality datasets. Once water quality data are digitized and tools are developed, managers can

Suggested Citation:"2 Coastal Mapping Needs and Activities." National Research Council. 2004. A Geospatial Framework for the Coastal Zone: National Needs for Coastal Mapping and Charting. Washington, DC: The National Academies Press. doi: 10.17226/10947.
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overlay pollutant source data with habitat and other relevant source data layers on a consistent mapping framework.

Coastal Hazards

Coasts are by nature dynamic, complex regions where a multitude of natural and man-made forces converge to produce change. To mitigate the impacts of detrimental change and enhance the efficacy of beneficial change, managers need to be able to understand the causes of such changes so that predictive tools and management strategies can be developed. This section focuses on the impact of coastal hazards—occurrences of detrimental natural change that threaten life, property, and human activities along the coast. A recent report (Heinz Center, 2002) noted that the rapid population growth and resulting increase in development along the coast during the past 50 years have resulted in greatly increased natural hazard risk to 160 million Americans and more than $3 trillion in coastal property.

The importance of shoreline and coastal hazard issues to the user community is clearly expressed in recent recommendations, made by the CSO to the U.S. Commission on Ocean Policy, that the USACE together with NOAA, FEMA, USGS, and other appropriate agencies should be tasked to “identify, compile, integrate and make available to the states data and information on shoreline change and processes, and work in conjunction with states and other local project sponsors to identify further information and data collection processes needed to fill the gaps in understanding a comprehensive approach to littoral system management” (CSO, 2002; pp. 19-20). The CSO also recommended that the Commission on Ocean Policy should “request that Congress appropriate additional funds authorized in section 215(c) of WRDA 99 for the National Shoreline Study [and] delineate erosion risks on flood insurance rate maps and incorporate erosion risk into the rate structure of the National Flood Insurance Program” (CSO, 2002; p. 20).

Among the more important coastal hazards are coastal flooding, tsunamis, sea level rise, shoreline erosion and accretion, and other geologic agents such as earthquakes and landslides:

Coastal Flooding

Coastal flooding is the greatest hazard faced by U.S. coastal communities in terms of natural threats to life and property. Flooding may occur as a result of storm rainfall and runoff or by inundation from the sea as a result of storm surge. In low-lying areas and along vulnerable coasts, storm-induced flooding may be exacerbated by high waves that accelerate

Suggested Citation:"2 Coastal Mapping Needs and Activities." National Research Council. 2004. A Geospatial Framework for the Coastal Zone: National Needs for Coastal Mapping and Charting. Washington, DC: The National Academies Press. doi: 10.17226/10947.
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shoreline erosion and increase structural damage. Although the federal government, through FEMA’s flood hazard program, helps reduce the costs of such flooding to individual homeowners, anecdotal evidence suggests that U.S. insurance companies are beginning to examine the efficacy of continuing to issue policies in coastal areas after paying out huge sums of money in the aftermath of recent hurricanes.

Tsunamis

Although relatively quiescent during the past century, historical records suggest that very large tsunamis, generated by seafloor seismic activity or submarine landslides, have had tremendous impact on coastal communities. A magnitude 7.8 earthquake in Alaska’s Aleutian Island Chain in 1946 generated a 35-meter tsunami that destroyed the USCG Scotch Cap lighthouse on Unimak Island and killed all five of its occupants. The tsunami reached the Hawaiian Islands 5 hours later, completely obliterating Hilo’s waterfront on the island of Hawaii and killing 159 people. Damage was estimated at $26 million (in 1946 dollars). As a result of this event, the Pacific Tsunami Warning Center was established in Hawaii. Alaska was struck again by a tsunami in 1964, in this case generated by the largest northern hemisphere earthquake of the 20th century. This magnitude 8.4 earthquake affected an area that was almost 1600 km long and more than 300 kilometers wide, elevating some areas by as much as 15 meters. The tsunami generated by this earthquake was very destructive in southeastern Alaska, in Vancouver Island (British Columbia), and in Washington, California, and Hawaii. The tsunami killed more than 120 people and caused more than $106 million in damages, making it the costliest ever to strike the western United States and Canada.7

Sea Level Rise

Historically, sea level variations have produced significant changes in shoreline position, with shorelines with gentle gradients being most affected. The current rate of sea level rise averages about 35 centimeters per century (Douglas, 1995), which is sufficient to increase the hazard posed by waves and storm surge and eventually inundate low-lying areas; exacerbate shoreline erosion and wetland loss, particularly in settings with low sedimentation rates; and exacerbate problems with saltwater intrusion into coastal aquifers.

Suggested Citation:"2 Coastal Mapping Needs and Activities." National Research Council. 2004. A Geospatial Framework for the Coastal Zone: National Needs for Coastal Mapping and Charting. Washington, DC: The National Academies Press. doi: 10.17226/10947.
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Shoreline Erosion and Accretion

Shoreline erosion is estimated to be occurring along 80 percent of the U.S. coastline, and retreating shorelines threaten vital habitats and coastal infrastructure (Heinz Center, 2000a; 2000b). Storm surge and local wave and current activity are the typical agents, but human activities such as armoring the shoreline or construction of jetties often exacerbate the problem. Erosion rates are often highest in areas where natural or human-induced subsidence is occurring. USGS and NOAA have recognized the need to adequately quantify future threats from shoreline erosion and are supporting federal and state efforts to quantify erosion rates and to map erosion hazards. Coastal hazards (e.g., offshore bars and shoals) can also be caused by shoreline accretion resulting from increased sediment input from cleared watersheds and/or by natural longshore drift.

Geologic Forces

Earthquakes, volcanoes and lava flows, and landslides may produce large and very rapid changes in coastal landforms. Yet compared to storm surges, waves, and other ocean processes, they do not readily lend themselves to quantitative prediction or forecasts. Therefore, geologic hazard reduction strategies usually incorporate a blend of statistical probabilities describing the threat, combined with laws and policies to regulate site and building requirements for coastal development.

Coastal Hazard Risk Reduction

Numerous tactics have been developed to reduce the risks associated with coastal hazards. A common approach involves preventing direct exposure to the threat by enacting laws prohibiting construction or activities in hazard-prone areas. Another is to provide early warnings when threats are perceived, such as sirens or radio alerts to warn the public of impending potentially catastrophic events (e.g., tsunami, storm surge). Construction practices can be modified to reduce—but not necessarily eliminate—the risk (e.g., elevating oceanfront homes above the estimated storm surge height or burying offshore cables and pipelines). In many areas, protective works reduce the threat of extreme weather and ocean hazards.

Regardless of the tactics used to reduce risk, long-term success has been achieved only when the nature of the threat has been understood and protective measures and/or practices have been designed accordingly. Table 2.1 provides some generic examples of the importance of coastal mapping and charting products to coastal hazards reduction, illustrating the dependence of design information for coastal hazards risk

Suggested Citation:"2 Coastal Mapping Needs and Activities." National Research Council. 2004. A Geospatial Framework for the Coastal Zone: National Needs for Coastal Mapping and Charting. Washington, DC: The National Academies Press. doi: 10.17226/10947.
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TABLE 2.1 Mapping/Charting Contributions to Coastal Hazard Risk Reduction

Hazard

Process, Model, and/or Product Type

Map or Chart Requirements

Coastal Flooding

Runoff and rainfall

Flood hazard maps, flood warnings, flood models

Topographic maps, DEMs

Storm surge

Flood hazard maps, surge models

Blended bathymetric/topographic maps and DEMs/DDMs

Sea level Rise

Inundation maps, risk assessments

Blended bathymetric/topographic maps and DEMs/DDMs

Waves

Wind waves

Wave contributions to storm surge, wave runup and wave setup

Blended nearshore bathymetric/ topographic maps and DEMs/DDMs

 

Extreme wave vulnerability assessment

Blended nearshore bathymetric/ topographic maps and DEMs/DDMs

Tsunami

Tsunami wave propagation, inundation maps, vulnerability assessment

Blended offshore/nearshore/ onshore bathymetric/topographic maps and geological maps

Shoreline Erosion and Accretion

Chronic

Sea/lake-level rise impacts on shoreline erosion and accretion, coastal change models

Repeated mapping to quantify rate and distribution of change

 

Sea/lake-level rise vulnerability assessment

Blended nearshore bathymetric/ topographic maps and DEMs/DDMs, habitat maps

Short-term

Hurricane-and storm-induced erosion and accretion

Pre-and post-storm mapping to quantify change

 

Storm vulnerability assessment

Blended nearshore bathymetric/ topographic maps and DEMs/DDMs; habitat maps

Winds

Topographic effects on extreme winds, wind models, wind vulnerability assessments

High-resolution DEMs

Landslides

Landslide vulnerability assessments

Blended bathymetric/topographic maps and DEMs/DDMs

Volcanic Activity

Volcano/lava vulnerability assessments

Onshore/offshore volcanic activity distribution maps

Earthquakes

Seismic vulnerability assessments

Onshore/offshore fault and seismic activity maps

Suggested Citation:"2 Coastal Mapping Needs and Activities." National Research Council. 2004. A Geospatial Framework for the Coastal Zone: National Needs for Coastal Mapping and Charting. Washington, DC: The National Academies Press. doi: 10.17226/10947.
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reduction on several types of coastal mapping and charting products. Of particular note is the common need for seamless earth surface depictions across the land-water interface (i.e., blended bathymetric/topographic digital elevation models and digital depth models—DEMs/DDMs). The specific mapping/charting needs identified by those agencies charged with assessing and/or reducing the risks and threats posed by coastal hazards are presented in Appendix A.

Minerals and Energy Management

The coastal zone is the repository of vast quantities of mineral, oil, and gas resources. In addition to the onshore fields located in the coastal zone, a significant percentage of the oil and natural gas produced in the United States (18 and 27 percent respectively; NOAA, 1998) comes from the federally controlled “Outer Continental Shelf”—that part of the continental margin adjacent to the United States that is not under control of the coastal state. Typically this is the area beyond 3 nautical miles from the shoreline but within the definition of the coastal zone used for this study. The percentage of oil and gas recovered from the offshore is expected to rise significantly over the next few years and with it the revenue collected by the federal government from oil and gas leases (NOAA, 1998). These revenues were between $3 billion and $4 billion in 1998, distributed to the general treasury, the Land and Water Conservation Fund, and the National Heritage Fund. In addition to the revenue generated for the federal government and the income generated by the private sector, the offshore oil and gas industry provides approximately 170,000 jobs in the United States (NOAA, 1998).

More than 20,000 offshore oil and gas wells have been drilled in the United States, a number that is expected to increase in the coming years as the offshore contains 15 and 19 percent of the nation’s proven oil and gas reserves, respectively, and is thought to contain more than 50 percent of the nation’s remaining undiscovered oil and gas reserves (NOAA, 1998). Although there are questions concerning economic viability, the coastal zone also has the potential for providing non-hydrocarbon energy sources such as tidal, wave, and wind power; several wind power projects are currently under regulatory review along the northeast to mid-Atlantic coast.

The coastal zone also contains vast deposits of sand and gravel, phosphorites, heavy minerals, and other valuable resources such as gold, titanium, and diamonds. These deposits are typically transported to the coastal zone by rivers and glaciers and then sorted by wave action. Sand and gravel together represent the largest mineral resource extracted from the coastal zone. They are used for beach replenishment, barrier island

Suggested Citation:"2 Coastal Mapping Needs and Activities." National Research Council. 2004. A Geospatial Framework for the Coastal Zone: National Needs for Coastal Mapping and Charting. Washington, DC: The National Academies Press. doi: 10.17226/10947.
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restoration, building materials (construction aggregates), and capping contaminated sediments. Technical innovations in dredging technology, including high-capacity underwater pumps and multiple-booster pumps, are rapidly increasing the efficiency of the extraction of sand, gravel, and other aggregate materials in the coastal zone (NOAA, 1998).

With the growing demands for reliable energy sources and the rapid growth of construction and road building in coastal regions, the demands for increased extraction of oil, gas, and aggregate minerals are putting tremendous pressure on those charged with managing and protecting the coastal zone. Within 3 miles of the shoreline—or three marine leagues for Texas and the Gulf Coast of Florida—the coastal state has jurisdiction in accordance with the Submerged Lands Act of 1953; beyond this limit, the federal government is the responsible body. The Minerals Management Service (MMS) is the federal agency charged with managing exploration and development of mineral and energy resources on the outer continental shelf as well as ensuring environmental protection and impact mitigation.

Specific MMS duties include:

  • Assessment of oil, natural gas, and mineral reserves;

  • Assessment of drilling hazards;

  • Siting of oil and natural gas facilities;

  • Selection and survey of oil pipeline routes;

  • Minerals production siting;

  • Offshore sand and gravel management (e.g., for coastal erosion mitigation, construction of berms for coastal protection);

  • Development and implementation of leasing programs;

  • Regulation of exploration and development; and

  • Provision of information needed to predict, assess, and manage environmental impacts from offshore gas and oil and marine mineral exploration, development, and production activities on human, marine, and coastal environments.

Those wishing to explore for and exploit energy and mineral resources, as well as those charged with managing and protecting those resources, will continue to require a wide range of mapping and charting products to meet their objectives. For those resources that extend across the land-water interface, these products will need to seamlessly extend across the shoreline. A fundamental requirement for these maps will be establishment of the geospatial framework for all subsequent studies—the reference frame provided by high-resolution bathymetry and topography. Beyond the reference frame data, a suite of source data products (acoustic imagery, optical imagery, offshore video and photography, direct sampling, etc.)

Suggested Citation:"2 Coastal Mapping Needs and Activities." National Research Council. 2004. A Geospatial Framework for the Coastal Zone: National Needs for Coastal Mapping and Charting. Washington, DC: The National Academies Press. doi: 10.17226/10947.
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will provide the basic context needed to understand the distribution and viability of resources as well as the engineering constraints needed for the siting of platforms, pipelines, and other structures.

In concert with studies aimed at identifying mineral and energy resources, baseline studies of local habitats will be required to understand the impact of any potential resource extraction. Habitat studies have their own set of mapping requirements (see above). Much work must also be done in the areas of risk assessment and mitigation. Plans must be in place to minimize and mitigate potential disruption of seafloor habitat and benthic communities resulting from the discharge of chemicals, drilling muds and cuttings, hydrocarbon emissions, and spills. Each of these requires detailed maps that depict reference frame, source, and derivative data.

Many resources are located below the seabed, and in these cases subbottom seismic profiling and other geophysical techniques (gravity, magnetics, resistivity, and heat flow) are used to better understand and map the structure and distribution of subsurface features. These datasets will also need to be integrated into the basic geospatial framework, adding a three-dimensional mapping component.

Given the breadth of needs associated with oil, gas, and mineral resource extraction in the coastal zone, the range of mapping products required for exploration, exploitation, management, regulation, protection, and mitigation involves almost every conceivable type and form of map or chart. The key to the successful balance of exploitation and environmental protection will be the availability for coastal managers of easily accessible and easily manageable data that can be seamlessly integrated and fused. Ensuring that such datasets are readily available is a fundamental focus of this study.

Cultural Resources Management

Cultural resources along the nation’s coasts and offshore areas include coastal and maritime parks, maritime preservation sites, underwater and coastal archeological sites (including Native American middens, rock art sites, excavation sites), maritime national historic landmarks, and national monuments (including lighthouses, life-saving stations, vessels, forts, submerged and coastal shipwrecks, and submerged historic docks and launches). Each of these is a valuable time capsule with the potential for revealing important aspects of the nation’s past.

In order to better understand and preserve this aspect of the nation’s heritage, coastal zone managers require detailed maps and documentation of cultural artifacts. Such documentation typically includes:

Suggested Citation:"2 Coastal Mapping Needs and Activities." National Research Council. 2004. A Geospatial Framework for the Coastal Zone: National Needs for Coastal Mapping and Charting. Washington, DC: The National Academies Press. doi: 10.17226/10947.
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  • Development of GIS-based, integrated cultural and natural resource data to be used for survey, identification, inventory, evaluation, protection, and preservation of cultural resources;

  • Development of management plans for preservation and recreational use of coastal cultural resources; and

  • Coordination among agencies and entities (e.g., state agencies, tribal nations, NOAA National Marine Sanctuary System, U.S. Navy, USCG, National Geographic Society) regarding submerged and coastal cultural resources throughout U.S. territories.

Many federal and state agencies have responsibilities for the management and protection of coastal cultural resources. Examples from among the federal agencies include the National Park Service, the National Marine Sanctuaries Program established by NOAA to protect important submerged cultural resources and which publishes a shipwreck database, and the Federal Energy Regulatory Commission and USACE which require offshore archeological surveys for pipeline and cable crossings and consideration of the impact of dredging projects on cultural resources. At the state level, archeological investigations commonly occur in connection with permitting activities as well as under the general purview of historical commissions and state archeological offices. Whether on land or underwater, such investigations are often a two-tiered approach involving a reconnaissance-level survey to determine the potential for significant finds, together with follow-up work, as necessary, to document the site. While increased availability of coastal mapping products expands our knowledge of underwater cultural resources, this availability also increases the risk that archeological sites could be tampered with by sport divers and treasure hunters. Data security related to cultural assets is a major concern.

The important source data needed for the management and protection of cultural resources in the coastal zone include:

  • High-resolution bathymetry (both reconnaissance and site-specific DDMs);

  • Coastal topography (high resolution DEMs);

  • Coastal configuration, including man-made historical infrastructure (location and identification of wrecks, submerged docks, launches, etc.);

  • Remote sensing data, including acoustic imagery (seismic profiling and sidescan sonar at both reconnaissance and site-specific scales) and magnetometer surveys;

  • Physical sampling (grabs, cores, etc.);

  • Underwater photographic and video imagery (site-specific) and diver surveys;

Suggested Citation:"2 Coastal Mapping Needs and Activities." National Research Council. 2004. A Geospatial Framework for the Coastal Zone: National Needs for Coastal Mapping and Charting. Washington, DC: The National Academies Press. doi: 10.17226/10947.
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  • Aerial and satellite imaging;

  • Shoreline delineation and reconstruction of old shorelines;

  • Soil and bottom sediment characteristics;

  • Marine boundaries to resolve jurisdictional issues; and

  • Written historical and descriptive data and original field notes.

From the above source data, products such as bathymetric and topographic maps and charts, underwater and aerial photographs and mosaics, and archeological site and artifact illustrations can be produced and used for the identification, assessment, monitoring, and protection of coastal cultural resources.

MAPPING NEEDS BEYOND THE COASTAL ZONE

The focus of this study has been the coastal zone, defined by the committee and the FGDC to extend to the limits of the U.S. territorial sea (12 nautical miles). This, of course, is an arbitrary and artificial mapping limit, as coastal and oceanographic processes are continuous offshore, and an emerging need for mapping well beyond the limit of the territorial sea should be acknowledged. One impetus is the need to document the geospatial framework for the wealth of living and nonliving resources within our nation’s EEZ (presently defined as 200 nautical miles from our territorial baseline—the official shoreline defined on NOAA charts). With fishing as well as hydrocarbon and mineral exploration moving to deeper and deeper waters, we find a pressing need (some of it legislated for example, by the Magnuson-Stevens Fishery Conservation Act) to better understand deep-water processes and environments. It is also of critical importance to establish baselines so that we may better understand and control the impacts of resource exploration and exploitation.

Contributing to this critical need for mapping is Article 76 of the United Nations Convention on the Law of the Sea (UNCLOS). Under this article, coastal states may claim jurisdiction over “submerged extensions of their continental margin beyond the recognized 200 nautical mile limit of their EEZ” (UN, 1983). The circumstances that define whether a coastal state can extend its jurisdiction are based on a complex set of rules that require an analysis of the depth and shape of the seafloor in areas of interest as well as an understanding of the thickness of underlying sediment. Consequently, full implementation of Article 76 requires the collection, assembly, and analysis of a body of relevant bathymetric, geologic, and geophysical data. The United States has not yet acceded to the UNCLOS, but growing recognition that implementation of Article 76 could confer jurisdiction and management authority over large (and potentially resource-rich) areas of the seabed beyond our current 200 nautical mile limit has

Suggested Citation:"2 Coastal Mapping Needs and Activities." National Research Council. 2004. A Geospatial Framework for the Coastal Zone: National Needs for Coastal Mapping and Charting. Washington, DC: The National Academies Press. doi: 10.17226/10947.
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renewed interest in the potential for a U.S. claim. In this context, there has been congressionally mandated activity to evaluate the content and completeness of the nation’s bathymetric and geophysical data holdings in areas surrounding the nation’s EEZ, with emphasis on ensuring their usefulness for substantiating the extension of resource or other national jurisdictions beyond the present 200 nautical mile limit (Mayer et al., 2002; Jakobsson et al., 2003). Congress has also recently funded the first year of data collection programs in support of a potential claim under Article 76.

It is the belief of this committee that the strategies and mechanisms established for coastal zone mapping, particularly in terms of survey registration, database development, data standards, and data distribution (see below), will be equally applicable to deeper-water mapping efforts. Applying these mechanisms and protocols to EEZ mapping will ensure that the deeper-water datasets will seamlessly merge with those collected in the nearshore region.

SUMMARY

There is an immense and substantiated need for geospatial data in the coastal zone to fulfill a wide variety of uses and applications. At least 15 federal agencies, state and local governments, the private sector, academia, and the general public are actively involved in the collection, processing, or dissemination of coastal zone data and/or products. The challenge facing the committee has been to evaluate the large volume of information provided and to determine whether there are gaps between the needs for geospatial data and the activities of those acquiring and processing data in the coastal zone (i.e., “unfulfilled needs”); to determine whether there are redundancies in effort, and to establish where and how efficiencies may be gained so that unfulfilled needs can be more effectively addressed.

Appendix A, and the expanded description presented in the committee’s interim report, formed the basis for the analysis presented in this chapter by summarizing federal agency needs and activities on an agency-by-agency basis. As Appendix A illustrates, the scope of the identified needs and activities is extremely complex and far-reaching; however, the committee’s review of users’ needs and the available information describing activities has revealed several cross-cutting issues related to unfulfilled needs. These issues reflect broad-based requirements for better data acquisition (both quality and quantity of data) and for a better and more efficient infrastructure to support and encourage cooperative collection, compilation, integration, processing, and dissemination of information. These cross-cutting issues highlight the following needs for:

Suggested Citation:"2 Coastal Mapping Needs and Activities." National Research Council. 2004. A Geospatial Framework for the Coastal Zone: National Needs for Coastal Mapping and Charting. Washington, DC: The National Academies Press. doi: 10.17226/10947.
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  • A consistent spatial framework for coastal data that allows a seamless transition from onshore to offshore, including clarification of offshore boundary definitions, a consistent geodetic framework for shoreline definitions, and easy transformation between various horizontal and vertical datums;

  • More and better (timely and accurate) primary source data, including high-resolution topography and shallow-water bathymetry; tide and current information; comprehensive imagery coverage; systematic and standardized bottom and habitat characterization; and human-use, land-cover, land-use, and coastal change data;

  • Consistent data, metadata, and mapping standards as well as a means to evaluate the accuracy of geospatial data;

  • Timely and straightforward access to the existing body of coastal data;

  • Increased inter- and intra-agency communication, cooperation, and coordination; and

  • Enhanced ability to interpret and apply spatial data and tools for decision making.

The review of agency activities also indicated apparent overlaps in the collection and processing of coastal zone geospatial data. In some cases these proved to be only “apparent” overlaps, in that some agencies had similar titles for activities that on the surface appeared to be the same but in actuality are not (e.g., the NOAA-CSC Community Vulnerability Assessment Tool used by FEMA and EPA’s Vulnerability Self Assessment Tool, which despite their similar names have completely different functions). In other cases, overlaps clearly do exist and must be addressed (e.g., redundancies of effort involving the acquisition of shoreline and habitat mapping data).

As the committee explored the intersection of needs and activities, the emphasis remained focused on efficiently establishing the fundamental information and tools necessary to fulfill the nation’s appropriate role in coastal zone mapping and charting. In the following chapter, the present inability to seamlessly combine onshore and offshore data, compare differently defined shorelines, and integrate and exchange existing and new coastal zone maps are described. The quantity and quality of coastal data are addressed in Chapter 4, with particular emphasis on the reference frame data (bathymetry and topography) that establish the fundamental geospatial framework for all other measurements. Chapter 5 addresses issues of timely and efficient access to these data. Chapter 6 identifies several areas where efficiencies can be gained by better coordination and collaboration and offers specific suggestions for improving interagency communication and collaboration. The strategies and recommendations associated with these issues collectively define our approach to fulfilling the vision outlined in Chapter 1.

Suggested Citation:"2 Coastal Mapping Needs and Activities." National Research Council. 2004. A Geospatial Framework for the Coastal Zone: National Needs for Coastal Mapping and Charting. Washington, DC: The National Academies Press. doi: 10.17226/10947.
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Suggested Citation:"2 Coastal Mapping Needs and Activities." National Research Council. 2004. A Geospatial Framework for the Coastal Zone: National Needs for Coastal Mapping and Charting. Washington, DC: The National Academies Press. doi: 10.17226/10947.
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Suggested Citation:"2 Coastal Mapping Needs and Activities." National Research Council. 2004. A Geospatial Framework for the Coastal Zone: National Needs for Coastal Mapping and Charting. Washington, DC: The National Academies Press. doi: 10.17226/10947.
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Suggested Citation:"2 Coastal Mapping Needs and Activities." National Research Council. 2004. A Geospatial Framework for the Coastal Zone: National Needs for Coastal Mapping and Charting. Washington, DC: The National Academies Press. doi: 10.17226/10947.
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Suggested Citation:"2 Coastal Mapping Needs and Activities." National Research Council. 2004. A Geospatial Framework for the Coastal Zone: National Needs for Coastal Mapping and Charting. Washington, DC: The National Academies Press. doi: 10.17226/10947.
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Suggested Citation:"2 Coastal Mapping Needs and Activities." National Research Council. 2004. A Geospatial Framework for the Coastal Zone: National Needs for Coastal Mapping and Charting. Washington, DC: The National Academies Press. doi: 10.17226/10947.
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Suggested Citation:"2 Coastal Mapping Needs and Activities." National Research Council. 2004. A Geospatial Framework for the Coastal Zone: National Needs for Coastal Mapping and Charting. Washington, DC: The National Academies Press. doi: 10.17226/10947.
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Suggested Citation:"2 Coastal Mapping Needs and Activities." National Research Council. 2004. A Geospatial Framework for the Coastal Zone: National Needs for Coastal Mapping and Charting. Washington, DC: The National Academies Press. doi: 10.17226/10947.
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Suggested Citation:"2 Coastal Mapping Needs and Activities." National Research Council. 2004. A Geospatial Framework for the Coastal Zone: National Needs for Coastal Mapping and Charting. Washington, DC: The National Academies Press. doi: 10.17226/10947.
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Suggested Citation:"2 Coastal Mapping Needs and Activities." National Research Council. 2004. A Geospatial Framework for the Coastal Zone: National Needs for Coastal Mapping and Charting. Washington, DC: The National Academies Press. doi: 10.17226/10947.
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Suggested Citation:"2 Coastal Mapping Needs and Activities." National Research Council. 2004. A Geospatial Framework for the Coastal Zone: National Needs for Coastal Mapping and Charting. Washington, DC: The National Academies Press. doi: 10.17226/10947.
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Suggested Citation:"2 Coastal Mapping Needs and Activities." National Research Council. 2004. A Geospatial Framework for the Coastal Zone: National Needs for Coastal Mapping and Charting. Washington, DC: The National Academies Press. doi: 10.17226/10947.
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Suggested Citation:"2 Coastal Mapping Needs and Activities." National Research Council. 2004. A Geospatial Framework for the Coastal Zone: National Needs for Coastal Mapping and Charting. Washington, DC: The National Academies Press. doi: 10.17226/10947.
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Suggested Citation:"2 Coastal Mapping Needs and Activities." National Research Council. 2004. A Geospatial Framework for the Coastal Zone: National Needs for Coastal Mapping and Charting. Washington, DC: The National Academies Press. doi: 10.17226/10947.
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Suggested Citation:"2 Coastal Mapping Needs and Activities." National Research Council. 2004. A Geospatial Framework for the Coastal Zone: National Needs for Coastal Mapping and Charting. Washington, DC: The National Academies Press. doi: 10.17226/10947.
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Suggested Citation:"2 Coastal Mapping Needs and Activities." National Research Council. 2004. A Geospatial Framework for the Coastal Zone: National Needs for Coastal Mapping and Charting. Washington, DC: The National Academies Press. doi: 10.17226/10947.
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Suggested Citation:"2 Coastal Mapping Needs and Activities." National Research Council. 2004. A Geospatial Framework for the Coastal Zone: National Needs for Coastal Mapping and Charting. Washington, DC: The National Academies Press. doi: 10.17226/10947.
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Suggested Citation:"2 Coastal Mapping Needs and Activities." National Research Council. 2004. A Geospatial Framework for the Coastal Zone: National Needs for Coastal Mapping and Charting. Washington, DC: The National Academies Press. doi: 10.17226/10947.
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Suggested Citation:"2 Coastal Mapping Needs and Activities." National Research Council. 2004. A Geospatial Framework for the Coastal Zone: National Needs for Coastal Mapping and Charting. Washington, DC: The National Academies Press. doi: 10.17226/10947.
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Page 37
Suggested Citation:"2 Coastal Mapping Needs and Activities." National Research Council. 2004. A Geospatial Framework for the Coastal Zone: National Needs for Coastal Mapping and Charting. Washington, DC: The National Academies Press. doi: 10.17226/10947.
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Suggested Citation:"2 Coastal Mapping Needs and Activities." National Research Council. 2004. A Geospatial Framework for the Coastal Zone: National Needs for Coastal Mapping and Charting. Washington, DC: The National Academies Press. doi: 10.17226/10947.
×
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Suggested Citation:"2 Coastal Mapping Needs and Activities." National Research Council. 2004. A Geospatial Framework for the Coastal Zone: National Needs for Coastal Mapping and Charting. Washington, DC: The National Academies Press. doi: 10.17226/10947.
×
Page 40
Suggested Citation:"2 Coastal Mapping Needs and Activities." National Research Council. 2004. A Geospatial Framework for the Coastal Zone: National Needs for Coastal Mapping and Charting. Washington, DC: The National Academies Press. doi: 10.17226/10947.
×
Page 41
Suggested Citation:"2 Coastal Mapping Needs and Activities." National Research Council. 2004. A Geospatial Framework for the Coastal Zone: National Needs for Coastal Mapping and Charting. Washington, DC: The National Academies Press. doi: 10.17226/10947.
×
Page 42
Suggested Citation:"2 Coastal Mapping Needs and Activities." National Research Council. 2004. A Geospatial Framework for the Coastal Zone: National Needs for Coastal Mapping and Charting. Washington, DC: The National Academies Press. doi: 10.17226/10947.
×
Page 43
Suggested Citation:"2 Coastal Mapping Needs and Activities." National Research Council. 2004. A Geospatial Framework for the Coastal Zone: National Needs for Coastal Mapping and Charting. Washington, DC: The National Academies Press. doi: 10.17226/10947.
×
Page 44
Suggested Citation:"2 Coastal Mapping Needs and Activities." National Research Council. 2004. A Geospatial Framework for the Coastal Zone: National Needs for Coastal Mapping and Charting. Washington, DC: The National Academies Press. doi: 10.17226/10947.
×
Page 45
Suggested Citation:"2 Coastal Mapping Needs and Activities." National Research Council. 2004. A Geospatial Framework for the Coastal Zone: National Needs for Coastal Mapping and Charting. Washington, DC: The National Academies Press. doi: 10.17226/10947.
×
Page 46
Suggested Citation:"2 Coastal Mapping Needs and Activities." National Research Council. 2004. A Geospatial Framework for the Coastal Zone: National Needs for Coastal Mapping and Charting. Washington, DC: The National Academies Press. doi: 10.17226/10947.
×
Page 47
Suggested Citation:"2 Coastal Mapping Needs and Activities." National Research Council. 2004. A Geospatial Framework for the Coastal Zone: National Needs for Coastal Mapping and Charting. Washington, DC: The National Academies Press. doi: 10.17226/10947.
×
Page 48
Suggested Citation:"2 Coastal Mapping Needs and Activities." National Research Council. 2004. A Geospatial Framework for the Coastal Zone: National Needs for Coastal Mapping and Charting. Washington, DC: The National Academies Press. doi: 10.17226/10947.
×
Page 49
Suggested Citation:"2 Coastal Mapping Needs and Activities." National Research Council. 2004. A Geospatial Framework for the Coastal Zone: National Needs for Coastal Mapping and Charting. Washington, DC: The National Academies Press. doi: 10.17226/10947.
×
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Suggested Citation:"2 Coastal Mapping Needs and Activities." National Research Council. 2004. A Geospatial Framework for the Coastal Zone: National Needs for Coastal Mapping and Charting. Washington, DC: The National Academies Press. doi: 10.17226/10947.
×
Page 51
Suggested Citation:"2 Coastal Mapping Needs and Activities." National Research Council. 2004. A Geospatial Framework for the Coastal Zone: National Needs for Coastal Mapping and Charting. Washington, DC: The National Academies Press. doi: 10.17226/10947.
×
Page 52
Suggested Citation:"2 Coastal Mapping Needs and Activities." National Research Council. 2004. A Geospatial Framework for the Coastal Zone: National Needs for Coastal Mapping and Charting. Washington, DC: The National Academies Press. doi: 10.17226/10947.
×
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Suggested Citation:"2 Coastal Mapping Needs and Activities." National Research Council. 2004. A Geospatial Framework for the Coastal Zone: National Needs for Coastal Mapping and Charting. Washington, DC: The National Academies Press. doi: 10.17226/10947.
×
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Suggested Citation:"2 Coastal Mapping Needs and Activities." National Research Council. 2004. A Geospatial Framework for the Coastal Zone: National Needs for Coastal Mapping and Charting. Washington, DC: The National Academies Press. doi: 10.17226/10947.
×
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Suggested Citation:"2 Coastal Mapping Needs and Activities." National Research Council. 2004. A Geospatial Framework for the Coastal Zone: National Needs for Coastal Mapping and Charting. Washington, DC: The National Academies Press. doi: 10.17226/10947.
×
Page 56
Suggested Citation:"2 Coastal Mapping Needs and Activities." National Research Council. 2004. A Geospatial Framework for the Coastal Zone: National Needs for Coastal Mapping and Charting. Washington, DC: The National Academies Press. doi: 10.17226/10947.
×
Page 57
Suggested Citation:"2 Coastal Mapping Needs and Activities." National Research Council. 2004. A Geospatial Framework for the Coastal Zone: National Needs for Coastal Mapping and Charting. Washington, DC: The National Academies Press. doi: 10.17226/10947.
×
Page 58
Suggested Citation:"2 Coastal Mapping Needs and Activities." National Research Council. 2004. A Geospatial Framework for the Coastal Zone: National Needs for Coastal Mapping and Charting. Washington, DC: The National Academies Press. doi: 10.17226/10947.
×
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Suggested Citation:"2 Coastal Mapping Needs and Activities." National Research Council. 2004. A Geospatial Framework for the Coastal Zone: National Needs for Coastal Mapping and Charting. Washington, DC: The National Academies Press. doi: 10.17226/10947.
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Suggested Citation:"2 Coastal Mapping Needs and Activities." National Research Council. 2004. A Geospatial Framework for the Coastal Zone: National Needs for Coastal Mapping and Charting. Washington, DC: The National Academies Press. doi: 10.17226/10947.
×
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Next: 3 A Common Coastal Zone Reference Frame: The Seamless Coastal Map and Consistent Shoreline »
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The coastal zone is of enormous importance to the well-being of the nation, as our lives and economy are inextricably linked to the features and activities that occur within this dynamic region. In order to understand and address the effects of natural and anthropogenic forces in the coastal zone, a holistic multidisciplinary framework is required to account for the interconnectivity of processes within the system. The foundation of this framework is accurate geospatial information—information that is depicted on maps and charts.

A Geospatial Framework for the Coastal Zone National Needs identifies and suggests mechanisms for addressing national needs for spatial information in the coastal zone. It identifies high priority needs, evaluates the potential for meeting those needs based on the current level of effort, and suggests steps to increase collaboration and ensure that the nation’s need for spatial information in the coastal zone is met in an efficient and timely manner.

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