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A Geospatial Framework for the Coastal Zone: National Needs for Coastal Mapping and Charting 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-
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A Geospatial Framework for the Coastal Zone: National Needs for Coastal Mapping and Charting 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).
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A Geospatial Framework for the Coastal Zone: National Needs for Coastal Mapping and Charting 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
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A Geospatial Framework for the Coastal Zone: National Needs for Coastal Mapping and Charting 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.
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A Geospatial Framework for the Coastal Zone: National Needs for Coastal Mapping and Charting 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
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A Geospatial Framework for the Coastal Zone: National Needs for Coastal Mapping and Charting 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
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A Geospatial Framework for the Coastal Zone: National Needs for Coastal Mapping and Charting 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
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A Geospatial Framework for the Coastal Zone: National Needs for Coastal Mapping and Charting 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
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A Geospatial Framework for the Coastal Zone: National Needs for Coastal Mapping and Charting 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.
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A Geospatial Framework for the Coastal Zone: National Needs for Coastal Mapping and Charting 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).
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A Geospatial Framework for the Coastal Zone: National Needs for Coastal Mapping and Charting 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
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A Geospatial Framework for the Coastal Zone: National Needs for Coastal Mapping and Charting 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
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A Geospatial Framework for the Coastal Zone: National Needs for Coastal Mapping and Charting 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. 7 See http://www.prh.noaa.gov/itic/library/about_tsu/faqs.html#1964.
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A Geospatial Framework for the Coastal Zone: National Needs for Coastal Mapping and Charting 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
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A Geospatial Framework for the Coastal Zone: National Needs for Coastal Mapping and Charting 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
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A Geospatial Framework for the Coastal Zone: National Needs for Coastal Mapping and Charting 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
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A Geospatial Framework for the Coastal Zone: National Needs for Coastal Mapping and Charting 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.)
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A Geospatial Framework for the Coastal Zone: National Needs for Coastal Mapping and Charting 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:
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A Geospatial Framework for the Coastal Zone: National Needs for Coastal Mapping and Charting 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;
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A Geospatial Framework for the Coastal Zone: National Needs for Coastal Mapping and Charting 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
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A Geospatial Framework for the Coastal Zone: National Needs for Coastal Mapping and Charting 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:
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A Geospatial Framework for the Coastal Zone: National Needs for Coastal Mapping and Charting 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.
Representative terms from entire chapter: