The U.S. Geological Survey (USGS) St. Petersburg Coastal and Marine Science Center (SPCMSC) conducted research to identify areas of seafloor elevation stability and instability based on elevation changes between the 1930’s and 2002 in the Upper Florida Keys (UFK) from Triumph Reef to Pickles Reef within a 234.2 square-kilometer area. USGS SPCMSC staff used seafloor elevation-change data from Yates and others (2017a) derived from an elevation-change analysis between two elevation datasets acquired in the 1930’s and 2001/2002 using the methods of Yates and others (2017b). Most of the elevation data from the 2001/2002 time period were collected during 2002, so as an abbreviated naming convention, we refer to this time period as 2002. A seafloor stability threshold was determined for the 1930’s-2002 UFK elevation-change dataset based on the vertical uncertainty of the 1930’s historical hydrographic surveys and 2002 digital elevation models (DEMs). Five stability categories (which incl ...

IMPORTANT IN THE OPEN DATA PORTAL THERE IS ONE FEATURE CLASS FOR ALL POTENTIOMETRIC SURFACE MAPS. IF YOU WANT JUST ONE TIME PERIOD CLICK ON THE TABLE TAB, THEN CLICK ON THE DATE FIELD. IN THE FILTER BOX ON THE RIGHT ENTER THE MAP YOU WANT (MAY 2000, SEPTEMBER 2015, ETC.). WHEN YOU CLICK THE DOWNLOAD DATASET BUTTON SELECT SPREADSHEET OR KML OR SHAPEFILE UNDER THE FILTERED DATASET OPTION. YOU WILL ONLY GET THE FILTERED DATA FROM THIS DOWNLOAD.Contour lines are created for the potentiometric surface of the upper Floridan aquifer from water level data submitted by the water management districts. The points associated with the water level data are added to Geostatistical Analyst and ordinary kriging is used to interpolate water level elevation values between the points. The Geostatistical Analyst layer is then converted to a grid (using GA Layer to grid tool) and then contour lines (using the Contour tool). Post editing is done to smooth the lines and fix areas that are hydrologically incorrect. The rules established for post editing are: 1) rivers intersecting the UFA follow the rule of V’s; 2) potentiometric surface contour line values don’t exceed the topographic digital elevation model (DEM) in unconfined areas; and 3) potentiometric surface contour lines don’t violate valid measured water level data. Errors are usually located where potentiometric highs are adjacent to potentiometric lows (areas where the gradient is high). Expert knowledge or additional information is used to correct the contour lines in these areas. Some additional data may be river stage values in rivers that intersect the Floridan aquifer or land elevation in unconfined areas. Contour lines created prior to May 2012 may be calculated using a different method. The potentiometric surface is only meant to describe water level elevation based on existing data for the time period measured. The contour interval for the statewide map is 10 feet and is not meant to supersede regional (water management district) or local (city) scale potentiometric surface maps.

The U.S. Geological Survey (USGS) St. Petersburg Coastal and Marine Science Center (SPCMSC) conducted research to identify areas of seafloor elevation stability and instability based on elevation changes between the 1930’s and 2016 along the Florida Reef Tract (FRT) from Miami to Key West within a 982.4 square-kilometer area. USGS SPCMSC staff used seafloor elevation-change data from Yates and others (2021) derived from an elevation-change analysis between two elevation datasets acquired in the 1930’s and 2016/2017 using the methods of Yates and others (2017). Most of the elevation data from the 2016/2017 time period were collected during 2016, so as an abbreviated naming convention, we refer to this time period as 2016. A seafloor stability threshold was determined for the 1930’s-2016 FRT elevation-change dataset based on the vertical uncertainty of the 1930’s historical hydrographic surveys and 2016 digital elevation models (DEMs). Five stability categories (which include, Stable: 0.0 meters (m) to ±0.24 m or 0.0 m to ±0.49 m; Moderately stable: ±0.25 m to ±0.49 m; Moderately unstable: ±0.50 m to ±0.74 m; Mostly unstable: ±0.75 m to ±0.99 m; and Unstable: ±1.00 m to Max/Min elevation change) were created and used to define levels of stability and instability for each elevation-change value (85,253 data points) based on the amount of erosion and accretion during the 1930’s to 2016 time period. Seafloor-stability point and triangulated irregular network (TIN) surface models were created at five different elevation-change data resolutions (1st order through 5th order) with each resolution becoming increasingly more detailed. In order to view the stability models at a larger extent, the stability point and surface (TIN) models were divided into four sub-regions: Biscayne Bay, Upper Key, Middle Keys, and Lower Keys. The stability models were used to determine the level of seafloor stability at potential areas of interest for coral restoration and 14 habitat types found along the FRT. Stability surface (TIN) models were used for areas defined by specific XY geographic points, while stability point models were used for areas defined by bounding box coordinate locations. This data release includes ArcGIS map packages containing the binned and color-coded stability point and surface (TIN) models, potential coral restoration locations, habitat files, and sub-region boundaries; maps of each stability model at full extent and for each sub-region; and data tables containing stability and elevation-change data for the potential coral restoration locations and habitat types. Data were collected under Florida Keys National Marine Sanctuary permit FKNMS-2016-068. Coral restoration locations were provided by Mote Marine Laboratory under Special Activity License SAL-18-1724-SCRP.

The U.S. Geological Survey (USGS) St. Petersburg Coastal and Marine Science Center (SPCMSC) conducted research to identify areas of seafloor elevation stability and instability based on elevation changes between the years of 2017 and 2018 at Crocker Reef near Islamorada, Florida (FL), within a 6.11 square-kilometer area. USGS SPCMSC staff used seafloor elevation-change data from Yates and others (2019) derived from an elevation-change analysis between two elevation datasets acquired in 2017 and 2018 using the methods of Yates and others (2017). A seafloor stability threshold was determined for the 2017-2018 Crocker Reef elevation-change dataset based on the vertical uncertainty of the 2017 and 2018 digital elevation models (DEMs). Five stability categories (which include, Stable: 0.0 meters (m) to ±0.24 m or 0.0 m to ±0.49 m; Moderately stable: ±0.25 m to ±0.49 m; Moderately unstable: ±0.50 m to ±0.74 m; Mostly unstable: ±0.75 m to ±0.99 m; and Unstable: ±1.00 m to Max/Min elevation change) were created and used to define levels of stability and instability for each elevation-change value (1,525,339 data points at 2-m horizontal resolution) based on the amount of erosion and accretion during the 2017 to 2018 time period. Seafloor-stability point and triangulated irregular network (TIN) surface models were created at five different elevation-change data resolutions (1st order through 5th order) with each resolution becoming increasingly more detailed. The stability point models were used to determine the level of seafloor stability at seven habitat types found at Crocker Reef. This data release includes ArcGIS map packages containing the binned and color-coded stability point and surface (TIN) models and habitat files; maps of each stability model; and data tables containing stability and elevation-change data for the habitat types. Data were collected under Florida Keys National Marine Sanctuary permit FKNMS-2016-068.

In this joint demonstration project for the Tampa Bay region, NOAA's National Ocean Service (NOS) and the U.S. Geological Survey (USGS) have merged NOAA bathymetric and USGS topographic data sets into a hybrid digital elevation model (DEM) with all data initially referenced to the ellipsoid, but transformable to any of 28 orthometric, 3-D, or tidal datums.A seamless bathymetric/topographic digital elevation model (DEM) was developed by merging the "best available" bathymetric data from NOAA and topographic data for USGS. Each of the datasets was initially processed independently to apply the "best available" criteria to select the data to be merged. Prior to merging, the selected data were transformed to a common reference coordinate system, both horizontally and vertically.The selected topography points within the shoreline buffer zone and the bathymetry points were gridded to produce a raster surface model with a 1-arc-second (30-meter) grid spacing to match the resolution of NED. The points were input to an implementation of the ANUDEM thin plate spline interpolation algorithm, which is optimized for generation of topographic surfaces. The bathymetry points could have been gridded independently of the topographic data, but the shoreline zone land elevations were included in the interpolation to ensure a better match of the bathymetric and topographic surfaces for the subsequent mosaicing step. To avoid introduction of any interpolation edge effects into the merged elevation model, the output grid from the interpolation was clipped to include only land elevations within 300 meters of the shoreline.The final processing step involved the mosaicing of the bathymetry grid and the NED elevation grid. The values in the 300-meter overlap area were blended by weighted averaging, where the weights for each grid are determined on a cell-by-cell basis according to the cell's proximity to the edges of the overlap area. The resulting final merged product is a seamless bathymetric/topographic model covering the Tampa Bay region at a grid spacing of 1-arc-second (30-meter). The vertical coordinates represent elevation in decimal meters relative to the GRS80 ellipsoid, and the horizontal coordinates are decimal degrees of latitude and longitude referenced to the NAD83 datum.This dataset is intended for geospatial applications that require seamless land elevation and water depth information in coastal environments.

This dataset was created to represent the land surface elevation at 1:24,000 scale for Florida. The elevation contour lines representing the land surface elevation were digitized from United States Geological survey 1:24,000 (7.5 minute) quadrangles and were compiled by South Florida, South West Florida, St. Johns River and Suwannee River Water Management Districts and FDEP. QA and corrections to the data were supplied by the Florida Department of Environmental Protection's Florida Geological Survey and the Division of Water Resource Management. This data, representing over 1,000 USGS topographic maps, spans a variety of contour intervals including 1 and 2 meter and 5 and 10 foot. The elevation values have been normalized to feet in the final data layer. Attributes for closed topographic depressions were also captured where closed (hautchered) features were identified and the lowest elevation determined using the closest contour line minus one-half the contour interval. This data was derived from the USGS 1:24,000 topographic map series. The data is more than 20 years old and is likely out-of-date in areas of high human activity.

The United States has an average elevation of roughly 2,500 feet (763m) above sea level, however there is a stark contrast in elevations across the country. Highest states Colorado is the highest state in the United States, with an average elevation of 6,800 feet (2,074m) above sea level. The 10 states with the highest average elevation are all in the western region of the country, as this is, by far, the most mountainous region in the country. The largest mountain ranges in the contiguous western states are the Rocky Mountains, Sierra Nevada, and Cascade Range, while the Appalachian Mountains is the longest range in the east - however, the highest point in the U.S. is Denali (Mount McKinley), found in Alaska. Lowest states At just 60 feet above sea level, Delaware is the state with the lowest elevation. Delaware is the second smallest state, behind Rhode Island, and is located on the east coast. Larger states with relatively low elevations are found in the southern region of the country - both Florida and Louisiana have an average elevation of just 100 feet (31m) above sea level, and large sections of these states are extremely vulnerable to flooding and rising sea levels, as well as intermittent tropical storms.

The High Accuracy Elevation Data Project collected elevation data (meters) on a 400 meter topographic grid with a vertical accuracy of +/- 15 centimeters to define the topography in South Florida. The data are referenced to the horizontal datum North American Datum 1983 (NAD 83) and the vertical datum North American Vertical Datum 1988 (NAVD 88). In some areas, the surveying was accomplished using airboats. Because access was a logistical problem with airboats, the USGS developed a helicopter-based instrument known as the Airborne Height Finder (AHF). All subsequent data collection used the AHF. Data were collected from the Loxahatchee National Wildlife Refuge, south through the Water Conservation Areas (1A, 2A, 2B, 3A, and 3B), Big Cypress National Park, the Everglades National Park, to the Florida Bay. The data are available for the areas shown on the USGS High Accuracy Elevation Data graphic at http://sofia.usgs.gov/exchange/desmond/desmondelev.html . The work was performed for Everglades ecosystem restoration purposes.

 The data are from regional topographic surveys to collect and provide elevation data to parameterize hydrologic and ecological numerical simulation models that are being developed for ecosystem restoration activities. Surveying services were also rendered to provide vertical reference points for numerous water level gauges. Modeling of sheet flow and water surface levels in the wetlands of South Florida is very sensitive to changes in elevation due to the expansive and extremely low relief terrain. Hydrologists determined minimum vertical accuracy requirements for the elevation data for use as input to hydrologic models. As a result, elevation data with a vertical accuracy specification of +/-15 centimeters (cm) relative to the North American Vertical Datum of 1988 (NAVD88) were collected in critical areas using state-of-the-art differential global positioning system (GPS) technology and data processing techniques.

This metadata record describes the ortho & lidar mapping of Sarasota County, FL. The mapping consists of lidar data collected using a Leica ALS-40 Lidar Sensor, contour generation, and production of natural color orthophotography with a 30-cm GSD using imagery collected with a Leica ADS-40 Aerial Digital Camera. This topographic survey for Sarasota County covers 572 square miles and was acquire...

This is the 1st release of the third version of an Everglades Depth Estimation Network (EDEN) digital elevation model (DEM) generated from certified airborne height finder (AHF) and airboat collected ground surface elevations for the Greater Everglades Region. This version includes all data collected and certified by the USGS prior to the conclusion of the AHF collection process. It differs from the previous elevation model (EDEN_EM_JAN07) in that the modeled area of WCA3N (all the WCA3A area north of I-75) is increased while the modeled area of the Big Cypress National Preserve (BNCP) has been both refined and reduced to the region where standard error of cross-validation points falls below 0.16 meters. EDEN offers a consistent and documented dataset that can be used to guide large-scale field operations, to integrate hydrologic and ecological responses, and to support biological and ecological assessments that measure ecosystem responses to Comprehensive Everglades Restoration Plan. To produce historic and near-real time maps of water depths, the EDEN requires a system-wide DEM of the ground surface.

This file is a modification of the eden dem released in October of 2007 (i.e., eden_em_oct07) in which the elevation values have been converted from meters (m) to centimeters(cm) for use by EDEN applications software. This file is intended specifically for use in the EDEN applications software. Aside from this difference in horizontal units, the following documentation applies.

The U.S. Geological Survey (USGS) St. Petersburg Coastal and Marine Science Center (SPCMSC) conducted research to identify areas of seafloor elevation stability and instability based on elevation changes between the years of 1938 and 2004 at Looe Key coral reef near Big Pine Key, Florida (FL), within a 19.06 square-kilometer area. USGS SPCMSC staff used seafloor elevation-change data from Yates and others (2017a) derived from an elevation-change analysis between two elevation datasets acquired in 1938 and 2004 using the methods of Yates and others (2017b). A seafloor stability threshold was determined for the 1938-2004 Looe Key elevation-change dataset based on the vertical uncertainty of the 1938 historical hydrographic survey and 2004 digital elevation model (DEM). Five stability categories (which include, Stable: 0.0 meters (m) to ±0.24 m or 0.0 m to ±0.49 m; Moderately stable: ±0.25 m to ±0.49 m; Moderately unstable: ±0.50 m to ±0.74 m; Mostly unstable: ±0.75 m to ±0.99 m; and Unstable: ±1.00 m to Max/Min elevation change) were created and used to define levels of stability and instability for each elevation-change value (1,687 data points) based on the amount of erosion and accretion during the 1938 to 2004 time period. Seafloor-stability point and triangulated irregular network (TIN) surface models were created at five different elevation-change data resolutions (1st order through 5th order) with each resolution becoming increasingly more detailed. The stability models were used to determine the level of seafloor stability at potential areas of interest for coral restoration and ten habitat types found at Looe Key. Stability surface (TIN) models were used for areas defined by specific XY geographic points, while stability point models were used for areas defined by bounding box coordinate locations. This data release includes ArcGIS map packages containing the binned and color-coded stability point and surface (TIN) models, potential coral restoration locations, and habitat files; maps of each stability model; and data tables containing stability and elevation-change data for the potential coral restoration locations and habitat types. Data were collected under Florida Keys National Marine Sanctuary permit FKNMS-2016-068. Coral restoration locations were provided by Mote Marine Laboratory under Special Activity License SAL-18-1724-SCRP.

The AHF system has been deployed in a series of survey campaigns to collect over 60,000 points covering Everglades National Park, Loxahatchee National Wildlife Refuge, Water Conservation Areas 2 and 3, portions of Big Cypress National Preserve, as well as areas along the Lake Okeechobee littoral zone. Since the AHF System is able to penetrate Everglades vegetation and water cover, it has provided an unprecedented regional view of Everglades topographic gradients and sub-water surface structure. These data are now being used to simulate Everglades water flow with higher resolution and greater accuracy, to estimate water depths in real-time for field study planning, and as input for habitat models used to forecast the effects of water level changes on various important species. The elevation data collected through this project also formed the basic input to generate a regional topographic surface that is the basis for the Everglades Depth Estimation Network (EDEN). These high accuracy elevation data are made available to anyone through the South Florida Information Access website (http://sofia.usgs.gov) data exchange pages.

MAP Activity Accomplishment The USGS Airborne Height Finder (AHF) System was used to perform topographic surveys in Water Conservation Area 3A within the extents of the Lone Palm Head and North of Lone Palm Head 7.5-minute topographic map quadrangles as specified in the MAP/COE Interagency Agreement. The AHF system has been used throughout South Florida for elevation data collection because traditional surveying methods are too difficult, too costly, or simply impossible to use in the harsh wetland environment and broadly inaccessible terrain of the Florida Everglades. This is especially true considering the shear size of the hydrodynamic and biological modeling domains. The AHF is a helicopter-based instrument that uses a GPS receiver, a computer, and a mechanized plumb bob to make measurements. These data were post processed to the reference stations that are part of the AHF geodetic control network. For reasons of accuracy, these reference stations are located no more then 15 kilometers from the helicopter during AHF operations. The GPS data were post processed using Ashtech’s PNAV On The Fly (OTF) software to obtain the trajectory of the AHF platform. These results are then processed through an in-house software package that separates the actual survey points and results from the trajectory. The points are manually checked to ensure data accuracy and completeness. Digital elevation models (DEMs) were then generated from the elevation point data. Existing elevation data derived from LiDAR data for this area were replaced with AHF derived DEMs for reasons of vertical accuracy. The DEMs have been posted on the South Florida Information Access (SOFIA) website: http://sofia.usgs.gov/exchange/desmond/desmondelev.html.

This digital elevation model (DEM) is a part of a series of DEMs produced for the National Oceanic and Atmospheric Administration Coastal Services Center's Sea Level Rise and Coastal Flooding Impacts Viewer. The DEMs created for this project were developed using the NOAA National Weather Service's Weather Forecast Office (WFO) boundaries. Because the WFO boundaries can cover large areas, the WFO DEM was divided into smaller DEMs to ensure more manageable file sizes. The Tampa (FL) WFO DEM was split into two smaller DEMs. They are divided along county lines and are: 1. Tampa (FL) WFO - Citrus, Hernando, Pasco, Pinellas, and Hillsborough Counties 2. Tampa (FL) WFO - Manatee, Sarasota, Charlotte, and Lee CountiesThis is Tampa Bay file 1 of 2. This metadata record describes the DEM for Tampa (FL) WFO - Citrus, Hernando, Pasco, Pinellas, and Hillsborough Counties. The DEM includes the best available lidar data known to exist at the time of DEM creation for the coastal areas of Citrus, Hernando, Pasco, Pinellas, and Hillsborough counties, that met project specifications.The DEM is derived from LiDAR datasets collected for the Florida Department of Emergency Management (FDEM) and the Southwest Florida Water Management District (SWFWMD). The FDEM LiDAR data for Manatee, Sarasota, Charlotte and Lee Counties was collected in 2007 and 2008. Small portions of Manatee and Charlotte Counties were collected in 2005. Hydrographic breaklines used in the creation of the DEM were obtained from FDEM and SWFWMD. In some cases, the National Wetlands Inventory and National Hydrography Dataset were used to supplement breaklines from FDEM and SWFWMD. The DEMs are hydro flattened such that water elevations are less than or equal to 0 meters.The DEM is referenced vertically to the North American Vertical Datum of 1988 (NAVD88) with vertical units of meters and horizontally to the North American Datum of 1983 (NAD83). The resolution of the DEM is approximately 5 meters.The NOAA Coastal Services Center has developed high-resolution digital elevation models (DEMs) for use in the Center's Sea Level Rise And Coastal Flooding Impacts internet mapping application. These DEMs serve as source datasets used to derive data to visualize the impacts of inundation resulting from sea level rise along the coastal United States and its territories.The dataset is provided "as is," without warranty to its performance, merchantable state, or fitness for any particular purpose. The entire risk associated with the results and performance of this dataset is assumed by the user. This dataset should be used strictly as a planning reference and not for navigation, permitting, or other legal purposes.

NOAA's National Geophysical Data Center (NGDC) is building high-resolution digital elevation models (DEMs) for select U.S. coastal regions in the Gulf of Mexico. These integrated bathymetric-topographic DEMs were developed for NOAA Coast Survey Development Laboratory (CSDL) through the American Recovery and Reinvestment Act (ARRA) of 2009 to evaluate the utility of the Vertical Datum Transformation tool (VDatum), developed jointly by NOAA's Office of Coast Survey (OCS), National Geodetic Survey (NGS), and Center for Operational Oceanographic Products and Services (CO-OPS). Bathymetric, topographic, and shoreline data used in DEM compilation are obtained from various sources, including NGDC, the U.S. Coastal Services Center (CSC), the U.S. Office of Coast Survey (OCS), the U.S. Army Corps of Engineers (USACE), and other federal, state, and local government agencies, academic institutions, and private companies. DEMs are referenced to the vertical tidal datum of North American Vertical Datum of 1988 (NAVD 88) or Mean High Water (MHW) and horizontal datum of North American Datum of 1983 (NAD 83). Grid spacings for both DEMs are 1/3 arc-second (~10 meters).The DEM Global Mosaic is an image service providing access to bathymetric/topographic digital elevation models stewarded at NOAA's National Centers for Environmental Information (NCEI), along with the global GEBCO_2014 grid: http://www.gebco.net/data_and_products/gridded_bathymetry_data. NCEI builds and distributes high-resolution, coastal digital elevation models (DEMs) that integrate ocean bathymetry and land topography to support NOAA's mission to understand and predict changes in Earth's environment, and conserve and manage coastal and marine resources to meet our Nation's economic, social, and environmental needs. They can be used for modeling of coastal processes (tsunami inundation, storm surge, sea-level rise, contaminant dispersal, etc.), ecosystems management and habitat research, coastal and marine spatial planning, and hazard mitigation and community preparedness. This service is a general-purpose global, seamless bathymetry/topography mosaic. It combines DEMs from a variety of near sea-level vertical datums, such as mean high water (MHW), mean sea level (MSL), and North American Vertical Datum of 1988 (NAVD88). Elevation values have been rounded to the nearest meter, with DEM cell sizes going down to 1 arc-second. Higher-resolution DEMs, with greater elevation precision, are available in the companion NAVD88: http://noaa.maps.arcgis.com/home/item.html?id=e9ba2e7afb7d46cd878b34aa3bfce042 and MHW: http://noaa.maps.arcgis.com/home/item.html?id=3bc7611c1d904a5eaf90ecbec88fa799 mosaics. By default, the DEMs are drawn in order of cell size, with higher-resolution grids displayed on top of lower-resolution grids. If overlapping DEMs have the same resolution, the newer one is shown. Please see NCEI's corresponding DEM Footprints map service: http://noaa.maps.arcgis.com/home/item.html?id=d41f39c8a6684c54b62c8f1ab731d5ad for polygon footprints and more information about the individual DEMs used to create this composite view. In this visualization, the elevations/depths are displayed using this color ramp: http://gis.ngdc.noaa.gov/viewers/images/dem_color_scale.png.A map service showing the location and coverage of land and seafloor digital elevation models (DEMs) available from NOAA's National Centers for Environmental Information (NCEI). NCEI builds and distributes high-resolution, coastal digital elevation models (DEMs) that integrate ocean bathymetry and land topography to support NOAA's mission to understand and predict changes in Earth's environment, and conserve and manage coastal and marine resources to meet our Nation's economic, social, and environmental needs. They can be used for modeling of coastal processes (tsunami inundation, storm surge, sea-level rise, contaminant dispersal, etc.), ecosystems management and habitat research, coastal and marine spatial planning, and hazard mitigation and community preparedness. Layers available in the map service: Layers 1-4: DEMs by Category (includes various DEMs, both hosted at NCEI, and elsewhere on the web); Layers 6-11: NCEI DEM Projects (DEMs hosted at NCEI, color-coded by project); Layer 12: All NCEI Bathymetry DEMs (All bathymetry or bathy-topo DEMs hosted at NCEI).This is an image service providing access to bathymetric/topographic digital elevation models stewarded at NOAA's National Centers for Environmental Information (NCEI), with vertical units referenced to mean high water (NAVD88). NCEI builds and distributes high-resolution, coastal digital elevation models (DEMs) that integrate ocean bathymetry and land topography to support NOAA's mission to understand and predict changes in Earth's environment, and conserve and manage coastal and marine resources to meet our Nation's economic, social, and environmental needs. They can be used for modeling of coastal processes (tsunami inundation, storm surge, sea-level rise, contaminant dispersal, etc.), ecosystems management and habitat research, coastal and marine spatial planning, and hazard mitigation and community preparedness. This service provides data from many individual DEMs combined together as a mosaic. By default, the rasters are drawn in order of cell size, with higher-resolution grids displayed on top of lower-resolution grids. If overlapping DEMs have the same resolution, the newer one is shown. Alternatively, a single DEM or group of DEMs can be isolated using a filter/definition query or using the 'Lock Raster 'mosaic method in ArcMap. This is one of three services displaying collections of DEMs that are referenced to common vertical datums: North American Vertical Datum of 1988 (NAVD88): http://noaa.maps.arcgis.com/home/item.html?id=e9ba2e7afb7d46cd878b34aa3bfce042, Mean High Water (MHW): http://noaa.maps.arcgis.com/home/item.html?id=3bc7611c1d904a5eaf90ecbec88fa799, and Mean Higher High Water: http://noaa.maps.arcgis.com/home/item.html?id=9471f8d4f43e48109de6275522856696. In addition, the DEM Global Mosaic is a general-purpose global, seamless bathymetry/topography mosaic containing all the DEMs together. Two services are available: http://noaa.maps.arcgis.com/home/item.html?id=c876e3c96a8642ab8557646a3b4fa0ff Elevation Values: http://noaa.maps.arcgis.com/home/item.html?id=c876e3c96a8642ab8557646a3b4fa0ff and Color Shaded Relief: http://noaa.maps.arcgis.com/home/item.html?id=feb3c625dc094112bb5281c17679c769. Please see the corresponding DEM Footprints map service: http://noaa.maps.arcgis.com/home/item.html?id=d41f39c8a6684c54b62c8f1ab731d5ad for polygon footprints and more information about the individual DEMs used to create this composite view. This service has several server-side functions available. These can be selected in the ArcGIS Online layer using 'Image Display ', or in ArcMap under 'Processing Templates '. None: The default. Provides elevation/depth values in meters relative to the NAVD88 vertical datum. ColorHillshade: An elevation-tinted hillshade visualization. The depths are displayed using this color ramp: http://gis.ngdc.noaa.gov/viewers/images/dem_color_scale.png. GrayscaleHillshade: A simple grayscale hillshade visualization. SlopeMapRGB: Slope in degrees, visualized using these colors: http://downloads.esri.com/esri_content_doc/landscape/SlopeMapLegend_V7b.png. SlopeNumericValues: Slope in degrees, returning the actual numeric values. AspectMapRGB: Orientation of the terrain (0-360 degrees), visualized using these colors: http://downloads.esri.com/esri_content_doc/landscape/AspectMapLegendPie_V7b.png. AspectNumericValues: Aspect in degrees, returning the actual numeric values.

NOAA's National Centers for Environmental Information (NCEI) is building high-resolution digital elevation models (DEMs) for select U.S. coastal regions. These integrated bathymetric-topographic DEMs are used to support individual coastal States as part of the National Tsunami Hazard Mitigation Program's (NTHMP) efforts to improve community preparedness and hazard mitigation. Bathymetric, topographic, and shoreline data used in DEM compilation are obtained from various sources including: NOAA; the U.S. Geological Survey (USGS); and other federal, state, and local government agencies, academic institutions, and private companies. DEMs are referenced to the vertical datum of NAVD 88 and horizontal datum of World Geodetic System 1984 geographic (WGS 84). Grid spacing for the DEM is 1/3 arc-second (~10 meters).

XYZ ASCII format high-resolution bathymetry data generated from the 2010 multibeam sonar survey of the West Florida Shelf-The Edges, Gulf of Mexico, Appalachicola, Florida.

To generate the land surface grid for this project, VIEWLOG was used to re-sample a 100-ft digital elevation model (DEM) of best-available data for the Lower West Coast planning region of the SFWMD. The original DEM was composited in 2013 from multiple sources. The 100 x 100 foot cell size of the DEM was resampled to a grid size of 2000 x 2000 feet (Liebermann and Bedell, 2013). The vertical datum is NGVD29. The contour interval is in feet.The objectives of this study were to create regional hydrogeologic maps including contour maps showing unit surfaces and thicknesses, and cross-sections representative of both the surficial aquifer system (SAS) and intermediate aquifer system (IAS). The maps, source data, and metadata used to generate these products will be archived in a manner suitable for model implementation and regulatory use in a publically accessible format. The results will be incorporated into the forthcoming Lower West Coast Surficial Aquifer System and Intermediate Aquifer System Model (LWCSIM), which will evaluate the potential impact of existing and projected groundwater withdrawals in all SAS and IAS aquifers within the region over the next several decades.For full documentation, please see Technical Publication WS-35, "Hydrogeologic Unit Mapping Update for the Lower West Coast Water Supply Planning Area," dated August 2015 by Elizabeth Geddes, Emily Richardson P.G., and Anne Dodd P.G. , Water Supply Bureau, Water Resources Division, South Florida Water Management District, West Palm Beach, Florida.https://www.sfwmd.gov/sites/default/files/documents/ws-35_lwc_hydrogeologic_mapping_083115.pdf

Dewberry collected 1200 square miles of lidar data in Hillsborough County, Florida. The nominal pulse spacing for this project was 1 point every 0.25 meters or a nominal pulse density of 16 points per square meter. Dewberrry used proprietary procedures to classify the LAS according to project specifications: 1-Unclassified, 2-Ground, 6-Building Rooftops, 7-Low Noise, 9-Water, 17- Bridge Deck...

ESCAMBIA: The Light Detection and Ranging (LiDAR) LAS dataset is a survey of select areas within Escambia County, Florida. These data were produced for Dewberry and Davis LLC. The Escambia County LiDAR Survey project area consists of approximately 803 square miles. The LiDAR point cloud was flown at a density sufficient to support a maximum final post spacing of 6 feet for unobscured areas. Lan...

This metadata record describes the ortho & lidar mapping of Pasco County, FL. The mapping consists of lidar data collected using a Leica ALS-40 Lidar Sensor, contour generation, and production of natural color orthophotography with a 30-cm GSD using imagery collected with a Leica ADS-40 Aerial Digital Camera.

Original contact information: Contact Name: Steve Dicks Contact Org: Southwest...