Meeting Research and Education Needs in Coastal Engineering (1999) / Chapter Skim
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1 National Importance of Coastal Engineering
1 National Importance of Coastal Engineering
Pages 6-25
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From page 6... ...
Coastal engineering involves the practice of civil engineering, as well as the sciences of oceanography and coastal geology, to control erosion; place, construct, and monitor coastal structures; nourish beaches; and develop and maintain ports, harbors, and related navigation facilities. More and more, the role of the coastal engineer is also expanding to encompass environmental and ecological issues, as the role of wetlands and water quality becomes more important.
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From page 7... ...
El Nino and the California Shoreline In late January and early February of 1998, the coast of California was hit by a series of powerful E1 Nino-influenced winter storms, causing 40 counties throughout the state, including most coastal counties, to be declared federal national disaster areas. The coastal damage included severely eroded beaches, flooded oceanfront homes, and the demolition of 10 bluff-top homes in the Pacifica area, just south of San Francisco, due to bluff failure that had undermined their foundations.
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From page 9... ...
Lucie Inlet, Florida, a man-made inlet on the east coast of Florida, has eroded landward hundreds of meters because of the interruption of the natural transport of sand along the coast. At the inlet, the amount of transport driven by the waves from north to south is on average 200,000 cubic yards (153,000 cubic meters)
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From page 10... ...
Port of New York and New Jersey The Port of New York and New Jersey, the nation's largest petroleum port and third largest container port, is in serious jeopardy of losing cargo and experiencing associated economic hardships unless harbors and entrance channels can be deepened and terminals expanded. The Port Authority of New York and New Jersey is no longer able to dispose of dredged material at sea because much of the material in the harbors and the 240 miles of federally maintained navigation channels has been reclassified as contaminated.
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From page 11... ...
Specific challenges to coastal engineers that will become more important in the future are listed below: Reduce the impacts and risks associated with coastal hazards, such as hurricanes, shoreline erosion, earthquakes, induced subsidence, and tsunamis. Restore the natural sand supply to the shoreline and restore the sand transport pathways along the coastal zone where it has been impacted by human activities.
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From page 12... ...
coastlines, whether the erosion of cliffs and bluffs along the Pacific coast or the erosion of barrier islands and beaches along the Atlantic and Gulf coasts, is an ongoing natural process that has been exacerbated by human activities, such as the reduction of coastal sand supplies (e.g., by damming rivers) and the obstruction of littoral drift by coastal structures.
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From page 13... ...
Coastal Hazards As coastal populations expand, losses from coastal hazards will continue to increase. These hazards include hurricanes, northeasters, and the rising sea level; earthquakes, bluff erosion, and E1 Nino-related storm damage on the West Coast; tsunamis in Hawaii, Alaska, and the Pacific coastal states; and the loss of sand supply along many coastlines because of human intervention.
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From page 14... ...
The most common approach to maintaining the shoreline is beach nourishment adding large quantities of beach quality sand to advance the shorelines seaward. Beach fill projects commonly cost millions of dollars and provide only short-term relief to the problem of erosion.
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From page 15... ...
In the case of an eroding beach on a barrier island, for example, the near-term option might be beach nourishment. Several decades later, however, after the performance of several projects had been evaluated and the prospects of an accelerated rise in sea level had been clarified, the range of management alternatives could be reevaluated and a new strategy developed.
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From page 16... ...
B Fenwick Island receiving beach nourishment sand pumped from approximately three miles offshore.
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From page 17... ...
Comprehensive studies would lead to a better understanding of the primary sand transport pathways at each inlet and the development of sand management strategies and plans to implement corrective actions. Sound sand management plans would give policy makers a much needed tool for formulating local, state, and national policies.
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From page 18... ...
The rise in sea level has been a topic of considerable debate for several decades, most recently in association with global warming. The long-term rate of 1.2 millimeters per year is apparently increasing and has already had significant effects on the barrier island shorelines of the Atlantic and Gulf coasts, as well as shorelines in the Mississippi Delta area, where, as a result of regional subsidence, the rates are about eight times the average.
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From page 19... ...
Long-term continuous monitoring programs could provide data for a comprehensive database on constructed projects, which could be made available to designers of future projects (NRC, 1995~. Human activities on beaches, marine parks, estuarine and bay waters, and other coastal resources often cause a decline in their overall environmental quality, the very quality of these resources that sustains tourism and recreation.
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From page 20... ...
This amount does not include funds spent by local port authorities for maintenance or new construction dredging. The fast and efficient operation of ports that can accommodate large ships will require real-time monitoring and modeling systems of currents, waves, and water levels; well maintained channels and navigation aids; safe, protected berthing sites; efficient methods for loading, unloading, storing, and moving
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From page 21... ...
NATIONAL IMPORTANCE OF COASTAL ENGINEERING 21 Dredging operations in the Port of Los Angeles. Courtesy of the Port of Los Angeles.
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From page 22... ...
Another option is capping contaminated sediments in pits in the harbor or at offshore disposal sites, which involves placing contaminated material on the ocean floor and covering it with a layer of clean clay and sand as a cap to prevent the material from moving. Because new port construction and maintenance usually occur in environmentally sensitive areas, ports often compensate for damage caused by dredging or other work by improving the environmental quality of other degraded areas in the region (e.g., establishing or improving coastal wetlands, providing new material for beach nourishment, or enhancing aquatic habitats)
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From page 23... ...
Environmental Preservation Early coastal engineering projects were conducted without regard to their adverse environmental impacts. In light of new concerns about the environmental quality and integrity of coastal zones, projects in the past 20 years have been required to show minimal adverse impacts and, wherever possible, positive environmental impacts (NRC, 19941.
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From page 24... ...
report based on a symposium convened by the NRC's Ocean Studies Board with the support of the Office of Naval Research and the Office of the Oceanographer of the Navy. This report, Oceanography and Naval Special Warfare: Opportunities and Challenges (NRC, 1997)
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From page 25... ...
For operations that involve existing harbors, the important questions are the maintenance or improvement of navigation to support large ships and the rapid repair or enhancement of port facilities. Operations Once a LOTS site has been selected and operations begin, coastal engineers must be able to forecast critical events that could disrupt operations or destroy critical facilities.
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