The High Resolution Digital Elevation Model (HRDEM) product is derived from airborne LiDAR data (mainly in the south) and satellite images in the north. The complete coverage of the Canadian territory is gradually being established. It includes a Digital Terrain Model (DTM), a Digital Surface Model (DSM) and other derived data. For DTM datasets, derived data available are slope, aspect, shaded relief, color relief and color shaded relief maps and for DSM datasets, derived data available are shaded relief, color relief and color shaded relief maps. The productive forest line is used to separate the northern and the southern parts of the country. This line is approximate and may change based on requirements. In the southern part of the country (south of the productive forest line), DTM and DSM datasets are generated from airborne LiDAR data. They are offered at a 1 m or 2 m resolution and projected to the UTM NAD83 (CSRS) coordinate system and the corresponding zones. The datasets at a 1 m resolution cover an area of 10 km x 10 km while datasets at a 2 m resolution cover an area of 20 km by 20 km. In the northern part of the country (north of the productive forest line), due to the low density of vegetation and infrastructure, only DSM datasets are generally generated. Most of these datasets have optical digital images as their source data. They are generated at a 2 m resolution using the Polar Stereographic North coordinate system referenced to WGS84 horizontal datum or UTM NAD83 (CSRS) coordinate system. Each dataset covers an area of 50 km by 50 km. For some locations in the north, DSM and DTM datasets can also be generated from airborne LiDAR data. In this case, these products will be generated with the same specifications as those generated from airborne LiDAR in the southern part of the country. The HRDEM product is referenced to the Canadian Geodetic Vertical Datum of 2013 (CGVD2013), which is now the reference standard for heights across Canada. Source data for HRDEM datasets is acquired through multiple projects with different partners. Since data is being acquired by project, there is no integration or edgematching done between projects. The tiles are aligned within each project. The product High Resolution Digital Elevation Model (HRDEM) is part of the CanElevation Series created in support to the National Elevation Data Strategy implemented by NRCan. Collaboration is a key factor to the success of the National Elevation Data Strategy. Refer to the “Supporting Document” section to access the list of the different partners including links to their respective data.

The EU-DEM is a Digital Surface Model (DSM) representing the first surface as illuminated by the sensors. EU-DEM covers the EEA39 countries and it has been produced by a consortium led by Indra, Intermap edited the EUDEM and AGI provided the water mask. The EU-DEM is a 3D raster dataset with elevations captured at 1 arc second postings (2.78E-4 degrees) or about every 30 meter. It is a hybrid product based on SRTM and ASTER GDEM data fused by a weighted averaging approach. Ownership of EU-DEM belongs to European Commision, DG Enterprise and Industry.

The projection onto an Inspire compliant grid of 25m resolution and the computation of a Slope raster have been performed by the Joint Research Centre of the European Commission (see file documentation/SPEC010_a100421-SLOP.pdf).

This dataset contains the slope for North America from the Hydrologic Derivatives for Modeling and Analysis (HDMA) database. The slope data were developed and distributed by processing units. There are 13 processing units for North America. The distribution files have the number of the processing unit appended to the end of the zip file name (e.g. na_slope_3_2.zip contains the slope data for unit 3-2). The HDMA database provides comprehensive and consistent global coverage of raster and vector topographically derived layers, including raster layers of digital elevation model (DEM) data, flow direction, flow accumulation, slope, and compound topographic index (CTI); and vector layers of streams and catchment boundaries. The coverage of the data is global (-180º, 180º, -90º, 90º) with the underlying DEM being a hybrid of three datasets: HydroSHEDS (Hydrological data and maps based on SHuttle Elevation Derivatives at multiple Scales), Global Multi-resolution Terrain Elevation Data 2010 (GMTED2010) and the Shuttle Radar Topography Mission (SRTM). For most of the globe south of 60º North, the raster resolution of the data is 3-arc-seconds, corresponding to the resolution of the SRTM. For the areas North of 60º, the resolution is 7.5-arc-seconds (the smallest resolution of the GMTED2010 dataset) except for Greenland, where the resolution is 30-arc-seconds. The streams and catchments are attributed with Pfafstetter codes, based on a hierarchical numbering system, that carry important topological information.

This dataset contains the slope for Africa from the Hydrologic Derivatives for Modeling and Analysis (HDMA) database. The slope data were developed and distributed by processing units. There are 19 processing units for Africa. The distribution files have the number of the processing unit appended to the end of the zip file name (e.g. af_slope_3_2.zip contains the slope data for unit 3-2).The HDMA database provides comprehensive and consistent global coverage of raster and vector topographically derived layers, including raster layers of digital elevation model (DEM) data, flow direction, flow accumulation, slope, and compound topographic index (CTI); and vector layers of streams and catchment boundaries. The coverage of the data is global (-180º, 180º, -90º, 90º) with the underlying DEM being a hybrid of three datasets: HydroSHEDS (Hydrological data and maps based on SHuttle Elevation Derivatives at multiple Scales), Global Multi-resolution Terrain Elevation Data 2010 (GMTED2010) and the Shuttle Radar Topography Mission (SRTM). For most of the globe south of 60º North, the raster resolution of the data is 3-arc-seconds, corresponding to the resolution of the SRTM. For the areas North of 60º, the resolution is 7.5-arc-seconds (the smallest resolution of the GMTED2010 dataset) except for Greenland, where the resolution is 30-arc-seconds. The streams and catchments are attributed with Pfafstetter codes, based on a hierarchical numbering system, that carry important topological information.

This dynamic image service provides numeric values representing ground surface heights, based on a digital terrain model (DTM). Heights are orthometric (sea level = 0), and water bodies that are above sea level have approximated nominal water heights.What can you do with this layer?Use for Visualization: This layer is generally not optimal for direct visualization. By default, 32 bit floating point values are returned, resulting in higher bandwidth requirements. Therefore, usage should be limited to applications requiring elevation data values. Alternatively, client applications can select from numerous additional functions, applied on the server, that return rendered data. For visualizations such as hillshade, slope, consider using the appropriate server-side function defined on this service.Use for Analysis: Yes. This layer provides data as floating point elevation values suitable for use in analysis.NOTE: The image service uses North America Albers Equal Area Conic projection (WKID: 102008) and resamples the data dynamically to the requested projection, extent and pixel size. For analyses requiring the highest accuracy, when using ArcGIS Desktop, you will need to use native coordinates (GCS_North_American_1983, WKID: 4269) and specify the native resolutions (0.0002777777777779 degrees) as the cell size geoprocessing environment setting and ensure that the request is aligned with the source pixels.Server Functions: This layer has server functions defined for the following elevation derivatives:Slope DegreesSlope PercentageAspectHillshadePre-symbolized Slope Degrees Map Data Sources: The data for this layer comes from NED 1 arc-second dataset from the USGS's National Elevation Dataset program with original source data in its native coordinate system.Data Coverage: The dataset covers the conterminous United States, Hawaii, partial Alaska, Puerto Rico, Territorial Islands of the United States, Canada and Mexico.This layer has query, identify, and export image services available. The layer is restricted to a 24,000 x 24,000 pixel limit. This layer is part of a larger collection of elevation layers that you can use to perform a variety of mapping analysis tasks.

Slope measures the inclination of the land surface from the horizontal. The percent slope and degrees slope products represent this inclination as the ratio of change in height to distance.

The slope (percentage) and slope (degrees) products were derived from the Smoothed Digital Elevation Model (DEM-S; ANZCW0703014016), which was derived from the 1 second resolution SRTM data acquired by NASA in February 2000. The calculation of slope from DEM-S accounted for the varying spacing between grid points in the geographic projection.

The 3 second resolution slope products were generated from the 1 second percent slope/degrees slope products and masked by the 3” water and ocean mask datasets.

Lineage: Source data 1. 1 arc-second percent slope product or 1 second degrees slope 2. 1 arc-second SRTM-derived Smoothed Digital Elevation Model (DEM-S; ANZCW0703014016). 3. 3 second resolution SRTM water body and ocean mask datasets

Slope calculation Slope was calculated from DEM-S using the finite difference method (Gallant and Wilson, 2000). The different spacing in the E-W and N-S directions due to the geographic projection of the data was accounted for by using the actual spacing in metres of the grid points calculated from the latitude.

The slope calculation was performed on 1° x 1° tiles, with overlaps to ensure correct values at tile edges.

The 3 second resolution versions were generated from the 1 second percent or degrees slope products. This was done by aggregating the 1” data over a 3 x 3 grid cell window and taking the mean of the nine values that contributed to each 3” output grid cell. The 3” data were then masked using the SRTM 3” ocean and water body datasets.

References Gallant, J.C. and Wilson, J.P. (2000) Primary topographic attributes, chapter 3 in Wilson, J.P. and Gallant, J.C. Terrain Analysis: Principles and Applications, John Wiley and Sons, New York.

This coverage was derived from U.S. Geological Survey National Elevation Dataset (NED) Digital Elevation Models (DEMs) for all of Ohio and portions of Indiana, Michigan, Kentucky, West Virginia, Pennsylvania, and New York. The dataset is a raster grid coverage representing a 30 meter grid cell size, or 1-arc second, and is in units of decimeters. The various NED source datasets used to create this dataset came primarily from state agencies who provide such data free of any fees or charges. More information about NED data can be found at http://gisdata.usgs.net/NED/default.asp.

Steep slopes for Anne Arundel County, MD. This dataset was created using ESRI's ArcGIS 11.3.0 with the Spatial Analyst extension. The source data was the County's 2023 Digital Elevation Model with a 1 foot resolution. The "Slope" command was used against the DEM to create a raster dataset from the raw DEMs. The "Reclassify" tool was then used to isolate the slope classifications based on County Code (15 - 24.99%, 25% and greater). Next, the "Extract by Attributes" tool was used to extract the desired classifications. Finally, the raster dataset was then converted to a polygon dataset by using the "Raster to Polygon" tool. Please download the shapefiles for the area of interest based on image below. Area 1, Area 2, Area 3, Area 4, Area 5, Area 6, Area 7, Area 8, Area 9, Area 10, Area 11, Area 12

This dataset contains the Digital Elevation Model (DEM) for North America from the Hydrologic Derivatives for Modeling and Analysis (HDMA) database. The DEM data were developed and distributed by processing units. There are 13 processing units for North America. The distribution files have the number of the processing unit appended to the end of the zip file name (e.g. na_dem_3_2.zip contains the DEM data for unit 3-2). The HDMA database provides comprehensive and consistent global coverage of raster and vector topographically derived layers, including raster layers of digital elevation model (DEM) data, flow direction, flow accumulation, slope, and compound topographic index (CTI); and vector layers of streams and catchment boundaries. The coverage of the data is global (-180º, 180º, -90º, 90º) with the underlying DEM being a hybrid of three datasets: HydroSHEDS (Hydrological data and maps based on SHuttle Elevation Derivatives at multiple Scales), Global Multi-resolution Terrain Elevation Data 2010 (GMTED2010) and the Shuttle Radar Topography Mission (SRTM). For most of the globe south of 60º North, the raster resolution of the data is 3-arc-seconds, corresponding to the resolution of the SRTM. For the areas North of 60º, the resolution is 7.5-arc-seconds (the smallest resolution of the GMTED2010 dataset) except for Greenland, where the resolution is 30-arc-seconds. The streams and catchments are attributed with Pfafstetter codes, based on a hierarchical numbering system, that carry important topological information.

The U.S. Geological Survey has developed a National Elevation Dataset (NED). The NED is a seamless mosaic of best-available elevation data. The 7.5-minute elevation data for the conterminous United States are the primary initial source data. In addition to the availability of complete 7.5-minute data, efficient processing methods were developed to filter production artifacts in the existing data, convert to the NAD83 datum, edge-match, and fill slivers of missing data at quadrangle seams. One of the effects of the NED processing steps is a much-improved base of elevation data for calculating slope and hydrologic derivatives. The specifications for the NED 1 arc second and 1/3 arc second data are: Geographic coordinate system Horizontal datum of NAD83, except for AK which is NAD27 Vertical datum of NAVD88, except for AK which is NAVD29 Z units of meters.Source data for this service are from the U.S. Geological Survey. These data were provided to the University of Idaho Library in November, 2004 by Mr. Tracy Fuller, USGS Idaho Mapping Liaison, Boise, Idaho.

The High Resolution Digital Elevation Model Mosaic provides a unique and continuous representation of the high resolution elevation data available across the country. The High Resolution Digital Elevation Model (HRDEM) product used is derived from airborne LiDAR data (mainly in the south) and satellite images in the north. The mosaic is available for both the Digital Terrain Model (DTM) and the Digital Surface Model (DSM) from web mapping services. It is part of the CanElevation Series created to support the National Elevation Data Strategy implemented by NRCan. This strategy aims to increase Canada's coverage of high-resolution elevation data and increase the accessibility of the products. Unlike the HRDEM product in the same series, which is distributed by acquisition project without integration between projects, the mosaic is created to provide a single, continuous representation of strategy data. The most recent datasets for a given territory are used to generate the mosaic. This mosaic is disseminated through the Data Cube Platform, implemented by NRCan using geospatial big data management technologies. These technologies enable the rapid and efficient visualization of high-resolution geospatial data and allow for the rapid generation of dynamically derived products. The mosaic is available from Web Map Services (WMS), Web Coverage Services (WCS) and SpatioTemporal Asset Catalog (STAC) collections. Accessible data includes the Digital Terrain Model (DTM), the Digital Surface Model (DSM) and derived products such as shaded relief and slope. The mosaic is referenced to the Canadian Height Reference System 2013 (CGVD2013) which is the reference standard for orthometric heights across Canada. Source data for HRDEM datasets used to create the mosaic is acquired through multiple projects with different partners. Collaboration is a key factor to the success of the National Elevation Strategy. Refer to the “Supporting Document” section to access the list of the different partners including links to their respective data.

The National Elevation Dataset (NED) is a new raster product assembled by the U.S. Geological Survey. The NED is a seamless mosaic of best-available elevation data with a consistent datum, elevation unit, and projection. Data corrections were made in the NED assembly process to minimize artifacts, perform edge matching, and fill sliver areas of missing data. One of the effects of the NED processing steps is a much-improved base of elevation data for calculating slope and hydrologic derivatives. Older DEM's produced by methods that are now obsolete are filtered during the NED assembly process to minimize artifacts that are commonly found in data produced by these methods. NED processing also includes steps to adjust values where adjacent DEM's do not match well, and to fill sliver areas of missing data between DEM's. These processing steps ensure that NED has no void areas and artificial discontinuities have been minimized. In cases where 7.5-minute DEM's have 10-meter resolution, the original source data will be at a higher resolution than the NED. In 1999 the Canaan Valley Institute and WVGISTC published the ERDAS IMAGINE mosaic. In 2002 the WV DEP published an ArcGrid mosaic that eliminated the noise artifact associated with hillshaded images. The WV DEP elevation grid was merged into a single block, reprojected using bilinear interpolation to a 30M cell size and cropped using a state boundary grid that was buffered outward 1km. The WV DEP elevation grid data was then rounded to the nearest integer value to reduce the file size.

This dataset contains the slope for Europe from the Hydrologic Derivatives for Modeling and Analysis (HDMA) database. The data were developed and distributed by processing units. There are 11 processing units for Europe. The distribution files have the number of the processing unit appended to the end of the zip file name (e.g. eu_dem_3_2.zip contains the DEM data for unit 3-2). The HDMA database provides comprehensive and consistent global coverage of raster and vector topographically derived layers, including raster layers of digital elevation model (DEM) data, flow direction, flow accumulation, slope, and compound topographic index (CTI); and vector layers of streams and catchment boundaries. The coverage of the data is global (-180º, 180º, -90º, 90º) with the underlying DEM being a hybrid of three datasets: HydroSHEDS (Hydrological data and maps based on SHuttle Elevation Derivatives at multiple Scales), Global Multi-resolution Terrain Elevation Data 2010 (GMTED2010) and the S ...

Abstract This dataset and its metadata statement were supplied to the Bioregional Assessment Programme by a third party and are presented here as originally supplied. Slope measures the inclination …Show full descriptionAbstract This dataset and its metadata statement were supplied to the Bioregional Assessment Programme by a third party and are presented here as originally supplied. Slope measures the inclination of the land surface from the horizontal. Degree slope represents this inclination in degrees from the horizontal. The degree slope product was derived from the Smoothed Digital Elevation Model (DEM-S; ANZCW0703014016), which was derived from the 1 second resolution SRTM data acquired by NASA in February 2000. The calculation of slope from DEM-S accounted for the varying spacing between grid points in the geographic projection. The 3 second resolution product was generated from the 1 second degree slope product and masked by the 3'' water and ocean mask datasets. Dataset History Lineage: Source data 1 second percent slope product 1 second SRTM-derived Smoothed Digital Elevation Model (DEM-S; ANZCW0703014016). 3 second resolution SRTM water body and ocean mask datasets Slope calculation Percent slope was calculated from DEM-S using the finite difference method (Gallant and Wilson, 2000). The different spacing in the E-W and N-S directions due to the geographic projection of the data was accounted for by using the actual spacing in metres of the grid points calculated from the latitude. The slope calculation was performed on 1deg x 1deg tiles, with overlaps to ensure correct values at tile edges. The 3 second resolution version was generated from the 1 second percent slope product. This was done by aggregating the 1second data over a 3 x 3 grid cell window and taking the mean of the nine values that contributed to each 3second output grid cell. The 3'' percent slope data were then masked using the SRTM 3'' ocean and water body datasets. This is version 0.1 of the 3'' resolution percent slope product. Later versions of this dataset may be produced however they are not expected at this time. Dataset Citation CSIRO (2012) Degree slope (3'' resolution) derived from 1 second DEM-S version 0.1. Bioregional Assessment Source Dataset. Viewed 14 June 2018, http://data.bioregionalassessments.gov.au/dataset/cbc5c230-cc87-49bb-a635-aec63e5a9723.

The Land Processes Distributed Active Archive Center (LP DAAC) is responsible for the archive and distribution of NASA Making Earth System Data Records for Use in Research Environments (MEaSUREs) Digital Elevation Model (DEM) version 1 (NASADEM_SC) dataset, which provides global slope and curvature elevation data at 1 arc second spacing.

NASADEM data products were derived from original telemetry data from the Shuttle Radar Topography Mission (SRTM), a collaboration between NASA and the National Geospatial-Intelligence Agency (NGA), as well as participation from the German and Italian space agencies. SRTM's primary focus was to generate a near-global DEM of the Earth using radar interferometry. It was a primary component of the payload on space shuttle Endeavour during its STS-99 mission, which was launched on February 11, 2000, and flew for 11 days.

In addition to Terra Advanced Spaceborne Thermal and Reflection Radiometer (ASTER) Global Digital Elevation Model (GDEM) Version 2 data, NASADEM also relied on Ice, Cloud, and Land Elevation Satellite (ICESat) Geoscience Laser Altimeter System (GLAS) ground control points of its lidar shots to improve surface elevation measurements that led to improved geolocation accuracy. Other reprocessing improvements include the conversion to geoid reference and the use of GDEMs and Advanced Land Observing Satellite Panchromatic Remote-sensing instrument for Stereo Mapping (PRISM) AW3D30 DEM, and interpolation for void filling.

NASADEM are distributed in 1 degree latitude by 1 degree longitude tiles and consist of all land between 60° N and 56° S latitude. This accounts for about 80% of Earth's total landmass.

NASADEM_SC data product layers include slope, aspect angle, profile curvature, plan curvature, and an updated SRTM water body dataset (water mask). A low-resolution browse image showing slope is also available for each NASADEM_SC granule.

GTOPO30 is a global digital elevation model (DEM) with a horizontal grid spacing of 30-arc seconds (0.008333333333333 degrees or approximately 1 kilometer), resulting in a DEM having dimensions of 21,600 rows and 43,200 columns. The horizontal coordinate system is decimal degrees of latitude and longitude referenced to World Geodetic System 84 (WGS84). The vertical units represent elevation in meters above mean sea level. The elevation values range from -407 to 8,752 meters. In the DEM, ocean areas have been masked as no data and have been assigned a value of -9999. Lowland coastal areas have an elevation of at least 1 meter (so in the event that a user reassigns the ocean value from -9999 to 0 the land boundary portrayal will be maintained). Small islands in the ocean less than approximately 1 square kilometer are not represented.

GTOPO30 was derived from several raster and vector sources of topographic information. These sources include: Digital Terrain Elevation Data, Digital Chart of the World, USGS 1-degree Digital Elevation Models, Army Map Service 1:1,000,000-scale Maps, International 1:1,000,000-scale Map of the World, Peru 1:1,000,000-scale Map, New Zealand DEM, and Antarctic digital Database.

GTOPO30 was developed to meet the needs of the geospatial data user community for regional and continental scale topographic data. The data are suitable for many regional and continental applications, such as climate modeling, continental-scale land cover mapping, extraction ofdrainage features for hydrologic modeling and geometric and atmospheric correction of medium and coarse resolution satellite image data.

An example of a recent application derived from GTOPO30 is HYDRO1k, a geographic database (at a resolution of 1 km) developed to provide comprehensive and consistent global coverage of topographically derived data sets, including streams, drainage basins, and ancillary layers . HYDRO1k provides a suite of geo-referenced data sets, both raster and vector, which will be of value for all users who need to organize, evaluate, or process hydrologic information on a continental scale. The raster data sets are the hydrologically correct DEM, derived flow directions, flow accumulations, slope, aspect, and a compound topographic (wetness) index. The derived streamlines and basins are distributed as vector data sets.

GTOPO30 was developed through a collaborative effort led by staff at the U.S. Geological Survey's EROS EDC. The following organizations participated by contributing funding or source data: the National Aeronautics and Space Administration (NASA), the United Nations Environment Programme/Global Resource Information Database (UNEP/GRID), the U.S. Agency for International Development (USAID), the Instituto Nacional de Estadistica Geografica e Informatica (INEGI) of Mexico, the Geographical Survey Institute (GSI) of Japan, Manaaki Whenua Landcare Research of New Zealand, and the Scientific Committee on Antarctic Research (SCAR).

This data release contains topographic information compiled for the Lower Roanoke River corridor located in eastern North Carolina. The Lower Roanoke River corridor includes the mainstem of the Roanoke River from Roanoke Rapids, NC (below the Roanoke Rapids dam) to the mouth of the Roanoke River at its confluence with the Albemarle Sound, and the associated floodplains and wetland areas surrounding the river. All datasets were derived from publicly available airborne light detection and radar (lidar) data collected in years 2003, 2014, and 2020. Data are organized into four categories: Digital Elevation Models (DEMs), Slopes, Digital Elevation Models of Difference (DoDs) in numeric format, and one DoD in categoric format. The DEM and Slope datasets represent static topographic conditions in 2003, 2014, or 2020. The DoD datasets reflect changes to topographic conditions between the years of 2003 and 2014, 2014 and 2020, and 2003 and 2020. These datasets can be used to support future examination of geomorphologic changes in the Lower Roanoke River basin. Due to the Lower Roanoke River corridor's extensive low-lying floodplain network, the lidar data and subsequent estimations of ground elevations (DEMs) were sensitive to differences in river stages across airborne lidar flight dates. Dense canopy cover and changes to lidar collection and processing techniques across the data acquisition years may also have affected the quality of data contained in this release. This data release contains four .zip files: (1) "DEM_3m.zip" contains three digital elevation model raster datasets in GeoTIFF format representing bare earth ground elevations in the years 2003, 2014, and 2020 and one metadata file in .xml format that describes the three digital elevation models. (2) "Slope_3m.zip" contains three slope raster datasets in GeoTIFF format representing bare earth ground slopes in the years 2003, 2014, and 2020 and one metadata file in .xml format that describes the three slope rasters. (3) "DoD_numeric_3m.zip" contains three digital elevation difference model raster datasets in GeoTIFF format representing bare earth ground elevation changes between the years 2003 and 2014, 2014 and 2020, and 2003 and 2020 and one metadata file in .xml format that describes the three digital elevation difference models. (4) "DoD_categoric_3m.zip" contains one digital elevation class difference raster dataset in GeoTIFF format representing bare earth ground class changes between the years 2003 and 2014, 2014 and 2020, and 2003 and 2020 and one metadata file in .xml format that describes the digital elevation class change models.

This raster dataset has been created using the "National Elevation Dataset (NED)" seamless download as originated by the US Geological Survey. Conservation values were determined by experts gathered by NLT for the Conservation Science Forum. Slopes 0 - 25% were assigned a value of 0. Slopes 25% - 40% were assigned a value of 1. Slopes greater that 40% were given a value of 3. Conservation values were determined by experts gathered by Natural Lands Trust through SmartConservation®. This data set is one of several that have been combined to create an overall terrestrial resources conservation value raster for the Central Appalachian Forest Ecoregion. Therefore the values were determined as a relative rank, comparable in value only to the other input terrestrial resources data. Conservation value ranges from 1 - 10 with 10 being the highest value.

This data set is a 100-m resolution Digital Elevation Model (DEM) for the Brooks Range and the North Slope of Alaska. The DEM was created by merging 100 National Elevation Dataset DEM tiles for areas of Alaska north of 67 degrees north latitude. A small area of Canada, derived from the global GTOPO30 DEM, is also included. The resulting DEM is in the Alaska Albers conical equal area projection, using the North American Datum of 1927 (NAD27). Data are available in GeoTIFF, Arc/INFO grid, and binary Band Interleaved by Line (BIL) formats.

A layer showing degrees of slope derived from Digital Elevation Models (DEMs) with a 3ft. grid cell size. Steepness is represented in degrees. The range of values is 0 degrees (flat) to 90 degrees (vertical). Data used to create the DEMs was derived from LiDAR collected by the NC Floodplain Mapping Program and processed by NC Department of Public Safety - Division of Emergency Management.Download county-based DEMs from the NC OneMap Direct Data Downloads. Data should not be downloaded using the map on the dataset's item page.