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16 An all-hazards approach to emergency management includes a broad range of incidents and events that have potential to impact transportation agencies and transportation systems opera- tions. States across the nation face different types of hazards. Coastal states can be at risk from hurricanes, tsunamis, storm surge, and sea level rise. Wide corridors of the central part of the country are tornado alleys, with a far higher probability of these storms occurring. Southwestern states experience severe heat, flash floods, and dust storms. Mountain states experience land- slides and avalanches, and much of the country experiences snow and ice stormsâwith different degrees of severity and different levels of preparedness for such events. All rivers, large and small, are potential flooding disasters. Earthquakes are not restricted to the west coast. There are seismic faults in many states that are overdue for a seismic event, and there are frequent seismic events in states, such as Oklahoma, that had not experienced any in the past. States throughout the nation are prone to forest and grassland wildfires. Along with natural hazards, technological hazards, such as cyber incidents and those related to aging infrastructure, need to be addressed as part of an all-hazards approach. Because todayâs transportation systems are integrated cyber and physical systems, there are greater cyber risks than ever, including the risk of a cyber incident impacting not only data but also the control systems and physical infrastructure of transportation agencies. Range of Hazards The latest Strategic National Risk Assessment stated that the nation continues to face a wide range of threats and hazards including the following: Natural hazards, including hurricanes, earthquakes, tornadoes, droughts, wildfires, winter storms, and floods, affect various parts of the nation; climate change may increase the severity of their impacts. A virulent strain of pandemic influenza or human and animal infectious diseases could cause significant loss of life and economic loss. Technological and accidental hazards, such as transportation system failures, dam failures, and chemical spills or releases, may result in extensive fatalities and severe economic impacts, and these hazards may increase due to aging infrastructure. Terrorist organizations or affiliates may seek to acquire and use weapons of mass destruction (WMDs). At the same time, conventional terrorist threats persist, such as âlone actorsâ using explosives, and armed attacks. Cyberattacks have the potential to cause cascading impacts with catastrophic consequences and can threaten the nationâs security, economy, public safety, and health. Also, cybersecurity is an important core capability and cyber preparedness needs to be integrated into every core capability (NPG 2015). Typical hazards and threats facing state transportation agencies and others are shown in Table 2. S E C T I O N 3 Nature and Degree of Hazards and Threats
Nature and Degree of Hazards and Threats 17 Natural Hazards Natural hazards span the range of predictability, with extreme weather events increasing in frequency (e.g., Superstorm Sandy, extensive Midwest flooding, powerful hurricanes, extensive wildfires). Weather events not only disrupt service, but they can also damage infrastructure. Space weather events are naturally occurring phenomena in the space environment that have the potential to disrupt technologies and systems in space and on Earth. These phenomena can affect satellite and airline operations, communications networks, navigation systems, the electric power grid, and other technologies and infrastructures critical to the daily function- ing, economic vitality, and security of the nation. Space weather can affect communication and navigation systems that are critical for safe and efficient transportation systems. For most natural hazards, geography is the primary variable in predicting likelihood of events. In many cases, geographic data on hazard likelihood is readily available and can be used with minimal cost or difficulty by appropriately skilled and equipped staff. There may be cases, however, where anecdotal evidence or judgment may need to be relied upon. The advanced age and deterioration of infrastructure can multiply risks from manmade or natural disasters and make the effects of an event much worse. Technological Hazards There are a variety of technological hazards that can impact transportation systems. Despite the best efforts of engineering and maintenance, the potential hazard or threat of a structural failure will always exist. Structure failure refers to any decrease in the physical integrity of the transportation asset to bear the weight required to carry passengers or freight. Structural failure may be sudden or gradual. The scope of this hazard or threat may be minimal, such as a crack in the wall requiring remediation or a pavement ripple requiring the temporary relocation of traffic. Integrity loss may also be catastrophic, resulting in total collapse or flooding of a struc- ture, causing widespread loss of assets and loss of life. There is no known method to guarantee that a structure will never fail or deteriorate. Proper design, construction, and maintenance may drastically decline the likelihood of a sudden failure; however, unseen geotechnical or aquatic forces may go undetected by asset owners. Natural Hazards Technological Hazards Human-Caused Hazards Avalanche Drought Earthquake Airplane crash Bridge collapse CBRNE Civil disturbance School violence Terrorist or criminal act Epidemic Flood Hurricane (tropical cyclone) Landslide or mudslide Tornado Tsunami (or seiche) Volcanic eruption Wildfire or facility fire Winter storm Wind or dust storm Space weather Solar events Dam or levee failure Electromagnetic pulse HAZMAT release Power failure Radiological release Train derailment Urban conflagration Loss of Internet connectivity Loss of telecommunications Equipment failure Sabotage War related Adapted from FEMA, Comprehensive Planning Guide 101, 2009; others added by the research team or from other transportation sources appear in italic type. Table 2. Sample hazards and threats list.
18 A Guide to Emergency Management at State Transportation Agencies Inconsistencies and lapses in the design, construction, and maintenance of an asset may coincide to create the conditions for a sudden structural failure. HAZMAT may be in liquid, solid, or gaseous form. The quantity of material introduced may be minimal but cause a hazard to users of the transportation system. HAZMAT includes common industrial cleaners used by transportation workers and canisters of pepper spray set off by transit users. In both circumstances, it is unlikely that the maintenance worker or the commuter entered the transportation system with the intent of discharging material into the air. Materials may also include hazardous liquid, which include debris or waste products moved into the transportation system by a vehicle, truck, or rail car. All HAZMAT requires specialized remediation that will close a roadway or transit segment to allow processing. Human-Caused Hazards Vehicle and vessel collisions are common types of human-caused hazards. For these hazards, the specific concern is the potential for collisions to cause very hot fires that can damage steel or timber infrastructure. The Federal Motor Carrier Safety Administration maintains detailed statistics on crash frequencies for large trucks, including tankers and HAZMAT. The frequency of vessel collisions can be site specific, depending on the waterway, navigational aids, climate, and maritime traffic. In particular, terrorists use a wide array of tactics and techniques to conduct an attack, including active shooters and assault by vehicle. Below is a list of the most likely tactics and threats: 1. Vehicle-Borne Improvised Explosive Device (VBIED): These include both landborne vehicles (i.e., truck bombs) that would be deployed against components reachable by land and water- borne vehicles (i.e., boat bombs) that would be deployed against any components reachable by water. 2. Hand-Emplaced Improvised Explosive Device (HEIED): These include contact explosive devices, such as satchel demolition charges and shaped charges, that are commonly used by military engineers and civilian demolition experts to precisely cut/sever structural members. 3. Non-Explosive Cutting Device (NECD): These include any non-explosive devices, such as saws, grinders, and torches that can be used to cut/sever structural members. 4. Vehicular Impact (VI): Similar to the VBIEDs, these include both landborne and waterborne vehicles, depending on the location of the component of concern. Interdependencies and Cascading Effects There are extensive interdependencies among transportation modes and other sectors, such as power and water. For example, the loss of a key bridge or tunnel can disrupt power and communications, along with transportation, because of co-located utilities. The transportation disruption can impact passenger and freight movement as well as the supply chain. Cascading events are events that occur as a result of an initial event. For example, wildfires in the dry season can lead to mudslides when the rains come. Heavy rains can result in dam over- flows or failures. A flashflood or lightning strike can disrupt power in an area and shut off traffic control systems, resulting in a serious traffic accident. If there was HAZMAT involved and a spill occurs, an evacuation of the area may be necessary. Because no entity has sufficient resources to protect against every threat and every hazard, state transportation agency investment in preparedness activities is necessarily risk-based. Understanding the dependencies within and between infrastructure and systems, along with the potential cascading effects, are developing areas of emergency management.
Nature and Degree of Hazards and Threats 19 Hazard Data Sources Information on potential hazards, including probability and possible effects, can be obtained from EMA, State Emergency Management and Civil Defense Agencies, National Weather Service (NWS), Environmental Protection Agency (EPA), U.S. Department of the Interior, U.S. Geological Survey (USGS), U.S. Army Corps of Engineers, and Department of Natural Resources (DNR). The following sections describe sources of relevant geographically referenced hazard data. Earthquake. USGS National Seismic Hazard Maps (Figure 3) display earthquake ground motions for various probability levels across the United States and are applied in seismic provi- sions of building codes, insurance rate structures, risk assessments, and other public policy. The National Seismic Hazard Maps are derived from seismic hazard curves calculated on a grid of sites across the United States that describe the annual frequency of exceeding a set of ground motions. Data and maps from the 2014 USGS National Seismic Hazard Mapping Project are available. The USGS Seismic Zone Maps are a probabilistic view (either 2% or 10%) that the ground acceleration will exceed the given value over 50 years. Depending on which model a state used, these would translate into the likelihood a state would use for its model. Maps for available periods [0.2 s, 1 s, peak ground acceleration (PGA)] and specified annual frequencies of exceedance can be calculated from the hazard curves. Figures depict probabilistic ground motions with a 2% probability of exceedance. Spectral accelerations are calculated for 5% damped linear elastic oscillators. All ground motions are calculated for site conditions with Vs30 = 760 m/s, corresponding to NEHRP B/C site class boundary. There is also a FEMA HAZUS data set for earthquakes. Landslide. Some jurisdictions that are especially sensitive to landslides have prepared hazard maps. For example, hazard mapping will become statewide in Washington State following a 2015 state law (RCW 43.92.025), which also covers earthquake and tsunami. The law specifies Light Detection and Ranging (LIDAR) mapping and specifically requires estimation Figure 3. USGS National Seismic Hazard Map (USGS 2011).
20 A Guide to Emergency Management at State Transportation Agencies of likelihood and consequence but does not mandate other parameters, such as return period, leaving these decisions to the state geologist. Agencies that have slope inventories may be able to compute the total centerline length of road affected by unstable slopes. The polling method describes a way that can be used to generate a frequency of landslide incidents. These would be gathered for all roads not just bridges. If the total length of slope incidents is divided by the inventory length of slopes and the number of years covered by the poll, this will provide an estimate of landslide probability per foot of road. For a given bridge, multiply this by the total roadway length (on and under the bridge) to give a site-specific extreme event probability. Agencies that experience debris flows from unstable slopes or freeze/thaw in deteriorating permafrost may identify extreme events associated with these phenomena that would be assessed in the same way as landslides. Storm surge. Florida DOT conducted an analysis of hurricane risk using a FEMA HAZUS data set of high wind speed (Sobanjo and Thompson 2013). In a Global Information System (GIS), this was associated with low elevations and coastal exposure to give an indication of storm surge vulnerability. Sheppard and Miller (2003) developed design storm surge hydro- graphs for the Florida coast. Figure 4 shows storm surge contours in Louisiana. This report listed recommended values for peak storm surge heights and corresponding likelihoods (50-year, 100-year, and 500-year occurrence) at various locations. The National Climate Assessment (2014), available online, has regional forecasts with down- loadable sea level rise maps. NCHRP Report 750: Strategic Issues Facing Transportation, Volume 2: Climate Change, Extreme Weather Events, and the Highway System: A Practitionerâs Guide and Research Report (2014) included sea level rise estimates by state. National Oceanic and Atmospheric Administration (NOAA) provides sea level rise and coastal flooding impacts data online, along with a Sea Level Rise Viewer at the DigitalCoast website. High wind. FEMAâs HAZUS data set can provide high wind data that can be geographi- cally associated with bridges. The NWS GIS Portal has data on tornado occurrence across the United States. Figure 4. Storm surge contours in Louisiana (Padgett et al. 2008).
Nature and Degree of Hazards and Threats 21 Flood. FEMA maintains the Digital Flood Insurance Rate Map Database, which depicts flood risk information and supporting data used to develop the risk data. The primary risk classifications used are the 1%-annual-chance flood event (100 year), the 0.2%-annual- chance flood event (500 year), and areas of minimal flood risk. Many state and county governments also maintain flood zone maps, which in many cases provide the basis for the FEMA maps. This information can be associated geographically with bridges to assign flood probabilities. Wildfire. Some states and the U.S. Forest Service maintain geographic data sets on historical wildfire experience. Extreme temperature. The NWS maintains maps of extreme temperature events across the nation. This information has been changing rapidly in recent years. The Climate Model Intercomparison Project (CMIP) Climate Data Processing Tool, an Excel-based tool developed for FHWA in 2015, utilizes the CMIP 3 and CMIP 5 databases to create usable statistics for transportation planners for temperature and precipitation variables. In 2010, FHWA published Regional Climate Change Effects: Useful Information for Transportation Agencies that has esti- mates of temperature, precipitation, sea level, and storm activity for every region in the country (i.e., Northeast, Southeast, Midwest, Great Plains, Southwest, Pacific Northwest, Alaska, Hawaii, and Puerto Rico). Most of the data sources described here are actively maintained and can change frequently. This makes it important to keep the assessment up to date. An updating interval of 4 to 6 years is suggested for hazards that are addressed in the bridge management system. In the absence of geographically referenced data, it may be possible to rely on anecdotal information, such as from news reports or studies taken from non-transportation domains. For example, the coasts of the Pacific Ocean and Gulf of Mexico have been subject to extensive monitoring and studies of sea level rise, which can be helpful in making judgments about the likelihood of storm surge and tsunami. Earthquakes of magnitude severe enough to damage transportation systems are reliably reported in the media, so a systematic search may provide sufficient information on strength and frequency. Local knowledge or news reports of floods can form the basis for a localized assessment of flood likelihood, especially in combination with site evidence of past flooding. The same is true of landslides. On the other hand, tornado and wildfire assessments should not rely on anecdotal reports, because they are an unreliable indicator of future event locations. Other sources include the following: FEMA 433: Using HAZUS-MH for Risk Assessment. http://www.fema.gov/fema-433- using-hazus-mh-risk-assessment. FEMA Map Service Center. This FEMA source provides map information for a variety of users affected by floods, including homeowners and renters, real estate and flood determi- nation agents, insurance agents, engineers and surveyors, and federal and exempt customers. There are flood maps, databases, map viewers, documents, and publications providing compre- hensive information. Further aspects of the site include FEMA-issued flood maps available for purchase, definitions of FEMA flood zone designations, and information about FIRMettes, a full-scale section of a FEMA Flood Insurance Rate Map (FIRM) that users can create and print at no charge (http://msc.fema.gov/webapp/wcs/stores/servlet/FemaWelcomeView?storeId= 10001&catalogId=10001&langId=-1).
22 A Guide to Emergency Management at State Transportation Agencies FEMA Flood Map Service Center (MSC). FEMA Flood MSC is the official public source for flood hazard information produced in support of the National Flood Insurance Program (NFIP). The MSC contains official flood maps, access to a range of other flood hazard products, and tools for better understanding flood risk (http://msc.fema.gov/portal/). Interior Geospatial Emergency Management System (IGEMS). The Department of Interior Geosciences and Environmental Change Science Center IGEMS, which replaced the Natural Hazards Support System (NHSS), provides online maps containing the latest available information on earthquakes, earthquake shakemaps, streamflow data, floods, volcanoes, wildfires, and weather hazards (http://igems.doi.gov/). NWS GIS Data Portal. Current weather, forecasts, and past weather data are available in Shapefile and other formats from the Data Portal. Hazards include tornadoes, hurricanes, rain, snowfall, floods, and other weather-related hazards (http://www.nws.noaa.gov/gis/shapepage.htm). Advanced Hydrologic Prediction Service. The NOAA Advanced Hydrologic Prediction Service (AHPS) is a web-based suite of forecast products that displays the magnitude and uncer- tainty of occurrence of floods or droughts, from hours to days and months, in advance. The majority of the observed water level data displayed on the AHPS web pages originates from the USGS National Streamflow Information Program, which maintains a national network of stream gauges. In addition, real-time water level information is collected from other federal, state, and local stream gauge networks (http://www.nws.noaa.gov/oh/ahps/). Hazard Tools There has been and continues to be significant deployment of new resources and rapidly developing technologies, such as ShakeCast and FloodCast, and remote, in-situ, or portable monitoring/damage detection techniques, such as sensors, sonar, radar, satellite imagery, and unmanned aerial vehicles, to support DOT activities. ShakeCast ShakeCast is a tool for raising situational awareness in emergency response. It is an open- source web application that retrieves data within minutes after an earthquake and generates hierarchical lists and maps of bridges most likely impacted. Notifications are then sent to responders within 10 min of the event. The ShakeCast software conducts an analysis of the measured or interpolated ground motion at each defined bridge location against a predetermined bridge fragility model. Responders can use the link in the email to access additional information on the ShakeCast website, such as viewing bridge data using maps and tables along with fragility analysis results. ShakeCast can also be used to evaluate current bridge inventory against scenario earth- quakes and significant historical events. Developed by the USGS with support from California DOT (Caltrans), the latest version (V3) was released in 2015. FloodCast FloodCast is a strategic framework for enhanced flood event decisionmaking. The completed project will help state DOTs manage risks and respond to flood and flash flood events.
Nature and Degree of Hazards and Threats 23 Risk Assessment and Threat and Hazard Identification and Risk Assessment (THIRA) The latest Strategic National Risk Assessment stated that the nation continues to face a wide range of threats and hazards including the following: â¢ Natural hazards, including hurricanes, earthquakes, tornadoes, droughts, wildfires, winter storms, and floods, affect various parts of the nation; climate change may increase the severity of their impacts. â¢ A virulent strain of pandemic influenza or human and animal infectious diseases could cause significant loss of life and economic loss. â¢ Technological and accidental hazards, such as transportation system failures, dam failures, chemical spills or releases, may result in extensive fatalities and severe economic impacts, and these may increase due to aging infrastructure. â¢ Terrorist organizations or affiliates may seek to acquire and use WMDs. At the same time, conven- tional terrorist threats persist, such as âlone actorsâ using explosives, and armed attacks. â¢ Cyberattacks have the potential to cause cascading impacts with catastrophic consequences and can threaten the nationâs security, economy, public safety, and health. Also, cybersecurity is an important core capability and cyber preparedness needs to be integrated into every core capability (NPG 2015). The FEMA Comprehensive Preparedness Guide (CPG) 201 presented the basic steps of a Threat and Hazard Identification and Risk Assessment (THIRA) that included a process for identifying community-specific threats and hazards. It addressed setting capability targets for each core capability identified in the NPG; the Second Edition of CPG 201 included an estima- tion of resources needed to meet those capability targets. The Second Edition CPG 201 also included changes to the THIRA process, streamlining the number of steps to conduct a THIRA and providing additional examples. THIRA is a foundation of the National Preparedness System. It is a four-step risk assessment process that provides an understanding of risks and estimates capability requirements (see Figure 5). The THIRA process standardizes the risk analysis process that emergency managers and homeland security professionals use and builds on existing state, local, tribal, and territorial Hazard Identification and Risk Assessments by doing the following: â¢ Broadening the threats and hazards considered to include human-caused threats and technological hazards. â¢ Incorporating the whole community into the planning process, including individuals; families; businesses; faith-based organizations (FBOs) and community-based organizations (CBOs); nonprofit groups; schools and academia; media outlets; and all levels of government, including local, state, tribal, territorial, and federal partners. â¢ Providing increased flexibility to account for community-specific factors. Figure 5. The THIRA process.
24 A Guide to Emergency Management at State Transportation Agencies The THIRA Process consists of the following: 1. Identify Threats and Hazards of Concern. Based on a combination of experience, forecast- ing, subject-matter expertise, and other available resources, identify a list of the threats and hazards of primary concern to the community. 2. Give the Threats and Hazards Context. Describe the threats and hazards of concern, showing how they may affect the community. 3. Establish Capability Targets. Assess each threat and hazard in context to develop a specific capability target for each core capability identified in the NPG. The capability target defines success for the capability. 4. Apply the Results. For each core capability, estimate the resources required to achieve the capability targets through the use of community assets and mutual aid, while also considering preparedness activities, including mitigation opportunities. Table 3 is an example template for organizing THIRA information. Table 3. Example template for organizing THIRA information.