The rivers of the Near East dataset is derived from the World Wildlife Fund's (WWF) HydroSHEDS drainage direction layer and a stream network layer. The source of the drainage direction layer was the 15-second Digital Elevation Model (DEM) from NASA's Shuttle Radar Topographic Mission (SRTM). The raster stream network was determined by using the HydroSHEDS flow accumulation grid, with a threshold of about 1000 km² upstream area.

The stream network dataset consists of the following information: the origin node of each arc in the network (FROM_NODE), the destination of each arc in the network (TO_NODE), the Strahler stream order of each arc in the network (STRAHLER), numerical code and name of the major basin that the arc falls within (MAJ_BAS and MAJ_NAME); - area of the major basin in square km that the arc falls within (MAJ_AREA); - numerical code and name of the sub-basin that the arc falls within (SUB_BAS and SUB_NAME); - area of the sub-basin in square km that the arc falls within (SUB_AREA); - numerical code of the sub-basin towards which the sub-basin flows that the arc falls within (TO_SUBBAS) (the codes -888 and -999 have been assigned respectively to internal sub-basins and to sub-basins draining into the sea). The attributes table now includes a field named "Regime" with tentative classification of perennial ("P") and intermittent ("I") streams.

Supplemental Information:

This dataset is developed as part of a GIS-based information system on water resources for the Near East. It has been published in the framework of the AQUASTAT - programme of the Land and Water Division of the Food and Agriculture Organization of the United Nations.

Contact points:

Metadata contact: AQUASTAT FAO-UN Land and Water Division

Contact: Jippe Hoogeveen FAO-UN Land and Water Division

Contact: Livia Peiser FAO-UN Land and Water Division

Data lineage:

The linework of the map was obtained by converting the stream network to a feature dataset with the Hydrology toolset in ESRI ArcGIS.The Flow Direction and Stream Order grids were derived from hydrologically corrected elevation data with a resolution of 15 arc-seconds.The elevation dataset was part of a mapping product, HydroSHEDS, developed by the Conservation Science Program of World Wildlife Fund.Original input data had been obtained during NASA's Shuttle Radar Topography Mission (SRTM).

Online resources:

Download - Rivers of the Near East (ESRI shapefile)

For general information regarding the HydroSHEDS data product

For HydroSHEDS dataset download and technical information

Hydrological basins in the Near East

This dataset is the 20ft Digital Elevation Model (DEM) for all of Buncombe County, NC. The DEMs were developed from Light Detection and Ranging (LIDAR) data acquired January though February through April 2003, with partial re-flights for gap data in December 2003. Cell values in the DEMs were derived from a Triangulated Irregular Network (TIN) produced from the bare earth mass points and breaklines. The dataset was provided to the Buncombe County by the NC Floodplain Mapping Project as pre-release data in July and Sept 2006 .Specific information about individual data tiles can be obtained at www.ncfloodmaps.com

The rivers of South and East Asia dataset is derived from the World Wildlife Fund's (WWF) HydroSHEDS drainage direction layer and a stream network layer. The source of the drainage direction layer was the 15-second Digital Elevation Model (DEM) from NASA's Shuttle Radar Topographic Mission (SRTM). The raster stream network was determined by using the HydroSHEDS flow accumulation grid, with a threshold of about 1000 km² upstream area.

The stream network dataset consists of the following information: - the origin node of each arc in the network (FROM_NODE), the destination of each arc in the network (TO_NODE), the Strahler stream order of each arc in the network (STRAHLER), numerical code and name of the major basin that the arc falls within (MAJ_BAS and MAJ_NAME); - area of the major basin in square km that the arc falls within (MAJ_AREA); - numerical code and name of the sub-basin that the arc falls within (SUB_BAS and SUB_NAME); - area of the sub-basin in square km that the arc falls within (SUB_AREA); - numerical code of the sub-basin towards which the sub-basin flows that the arc falls within (TO_SUBBAS) (the codes -888 and -999 have been assigned respectively to internal sub-basins and to sub-basins draining into the sea).

The attributes table now includes a field named "Regime" with tentative classification of perennial ("P") and intermittent ("I") streams.

Supplemental Information:

This dataset is developed as part of a GIS-based information system on water resources for South America. It has been published in the framework of the AQUASTAT - programme of the Land and Water Division of the Food and Agriculture Organization of the United Nations.

Contact points:

Metadata contact: AQUASTAT FAO-UN Land and Water Division

Contact: Jippe Hoogeveen FAO-UN Land and Water Division

Contact: Livia Peiser FAO-UN Land and Water Division

Data lineage:

The linework of the map was obtained by converting the stream network to a feature dataset with the Hydrology toolset in ESRI ArcGIS.The Flow Direction and Stream Order grids were derived from hydrologically corrected elevation data with a resolution of 15 arc-seconds.The elevation dataset was part of a mapping product, HydroSHEDS, developed by the Conservation Science Program of World Wildlife Fund.Original input data had been obtained during NASA's Shuttle Radar Topography Mission (SRTM).

Online resources:

Download - Rivers of South and East Asia (ESRI shapefile)

General information regarding the HydroSHEDS data product

HydroSHEDS dataset download and technical information

Hydrological basins in South and East Asia

The rivers of South America are derived from the World Wildlife Fund's (WWF) HydroSHEDS drainage direction layer and a stream network layer.The drainage direction layer was created from NASA's Shuttle Radar Topographic Mission (SRTM) 15-second Digital Elevation Model (DEM).The raster stream network was determined by using the HydroSHEDS flow accumulation grid, with a threshold of about 100 km² upstream area.

The stream network dataset consists of the following information: the origin node of each arc in the network (FROM_NODE), the destination of each arc in the network (TO_NODE), the Strahler stream order of each arc in the network (STRAHLER), numerical code and name of the major basin that the arc falls within (MAJ_BAS and MAJ_NAME); - area of the major basin in square km that the arc falls within (MAJ_AREA); - numerical code and name of the sub-basin that the arc falls within (SUB_BAS and SUB_NAME); - area of the sub-basin in square km that the arc falls within (SUB_AREA); - numerical code of the sub-basin towards which the sub-basin flows that the arc falls within (TO_SUBBAS) (the codes -888 and -999 have been assigned respectively to internal sub-basins and to sub-basins draining into the sea). The attributes table now includes a field named "Regime" with tentative classification of perennial ("P") and intermittent ("I") streams.

Supplemental Information:

This dataset is developed as part of a GIS-based information system on water resources for South America. It has been published in the framework of the AQUASTAT - programme of the Land and Water Division of the Food and Agriculture Organization of the United Nations.

Contact points:

Metadata contact: AQUASTAT FAO-UN Land and Water Division

Contact: Jippe Hoogeveen FAO-UN Land and Water Division

Contact: Livia Peiser FAO-UN Land and Water Division

Data lineage:

The linework of the map was obtained by converting the stream network to a feature dataset with the Hydrology toolset in ESRI ArcGIS.The Flow Direction and Stream Order grids were derived from hydrologically corrected elevation data with a resolution of 15 arc-seconds.The elevation dataset was part of a mapping product, HydroSHEDS, developed by the Conservation Science Program of World Wildlife Fund.Original input data had been obtained during NASA's Shuttle Radar Topography Mission (SRTM).

Online resources:

Download - Rivers of South America (ESRI shapefile)

For general information regarding the HydroSHEDS data product

For HydroSHEDS dataset download and technical information

This resource contains data inputs and a Jupyter Notebook that is used to introduce Hydrologic Analysis using Terrain Analysis Using Digital Elevation Models (TauDEM) and Python. TauDEM is a free and open-source set of Digital Elevation Model (DEM) tools developed at Utah State University for the extraction and analysis of hydrologic information from topography. This resource is part of a HydroLearn Physical Hydrology learning module available at https://edx.hydrolearn.org/courses/course-v1:Utah_State_University+CEE6400+2019_Fall/about

In this activity, the student learns how to (1) derive hydrologically useful information from Digital Elevation Models (DEMs); (2) describe the sequence of steps involved in mapping stream networks, catchments, and watersheds; and (3) compute an approximate water balance for a watershed-based on publicly available data.

Please note that this exercise is designed for the Logan River watershed, which drains to USGS streamflow gauge 10109000 located just east of Logan, Utah. However, this Jupyter Notebook and the analysis can readily be applied to other locations of interest. If running the terrain analysis for other study sites, you need to prepare a DEM TIF file, an outlet shapefile for the area of interest, and the average annual streamflow and precipitation data. - There are several sources to obtain DEM data. In the U.S., the DEM data (with different spatial resolutions) can be obtained from the National Elevation Dataset available from the national map (http://viewer.nationalmap.gov/viewer/). Another DEM data source is the Shuttle Radar Topography Mission (https://www2.jpl.nasa.gov/srtm/), an international research effort that obtained digital elevation models on a near-global scale (search for Digital Elevation at https://www.usgs.gov/centers/eros/science/usgs-eros-archive-products-overview?qt-science_center_objects=0#qt-science_center_objects). - If not already available, you can generate the outlet shapefile by applying basic terrain analysis steps in geospatial information system models such as ArcGIS or QGIS. - You also need to obtain average annual streamflow and precipitation data for the watershed of interest to assess the annual water balance and calculate the runoff ratio in this exercise. In the U.S., the streamflow data can be obtained from the USGS NWIS website (https://waterdata.usgs.gov/nwis) and the precipitation from PRISM (https://prism.oregonstate.edu/normals/). Note that using other datasets may require preprocessing steps to make data ready to use for this exercise.

The USGS 3D Hydrography Program (3DHP) ArcGIS REST service (3DHP_all) from The National Map is the first of several data services that will be delivered by the 3D Hydrography Program. The 3DHP_all comprises a national network of flowlines, hydrolocations, and water bodies, and will include catchments, drainage areas, and flow network derivatives as they are populated in the future. The 3DHP_all service will provide access to a 3D-enabled geospatial hydrography vector dataset built from 3DHP data and intended to provide the most comprehensive but general rendering of 3DHP data. 3DHP data is derived from elevation-derived hydrography (EDH) Elevation-Derived Hydrography Specifications | U.S. Geological Survey (usgs.gov) where available. Where EDH has not been collected, 3DHP data will be supplemented by data from the National Hydrography Dataset (NHD) National Hydrography Dataset | U.S. Geological Survey (usgs.gov). As further EDH data is collected, the EDH data will replace the NHD data in that data collection area. 3DHP data ingested from EDH sources will include catchments, drainage areas derived from catchments, and flowline network attribute derivatives.Use Constraints: _ None. All data are open and non-proprietary. However, users should be aware that temporal changes may have occurred since this dataset was collected and that some parts of this data may no longer represent actual conditions. Users should not use this data for critical applications without a full awareness of its limitations. This dataset is not intended to be used for site-specific regulatory determinations. Acknowledgment of the U.S. Geological Survey would be appreciated for products derived from these data.For additional information on the 3DHP, go to https://www.usgs.gov/3dhp.See https://apps.nationalmap.gov/help/ for assistance with The National Map viewer, download client, services, or metadata.

The dataset is a 10 m-resolution DEM in grid format covering the whole Italian territory. The DEM is encoded as “ESRI ASCII Raster” obtained by interpolating the original DEM in Triangular Irregular Network (TIN) format. The TIN version benefited from the systematic application of the DEST algorithm. The projection is UTM, the World Geodetic System 1984 (WGS 84). To provide the dataset as a single seamless DEM, the sole zone 32 N was selected, although about half of Italy belongs to zone 33 N. The database is arranged in 193 square tiles having 50 km side. Data e Risorse Questo dataset non ha dati ambiente terremoti vulcani

The Alberta Provincial Terrain is a component of the Alberta Provincial Digital Elevation Model. The Alberta Provincial Digital Elevation Model has five components: the Alberta Provincial Terrain, the Alberta Provincial 25 Metre Raster, the Alberta Provincial 100 Metre Raster, the Alberta Provincial 25 Metre Hillshade and the Alberta Provincial 100 Metre Hillshade. The source data is contained within the feature dataset that houses the Alberta Provincial Terrain. The source data consists of feature classes generated from the mass points, soft breaklines and hard breaklines that were stored as ASCII generate files in 1:20 000 scale National Topographic System (NTS) blocks. The source data has three origins: Digital Elevation Model: Alberta 1980 1995 60K, Southwestern Alberta 1979 1996 50K and Northeastern Alberta 1955 1986 50K. These three datasets were processed separately and tiled seamlessly along their borders. The Digital Elevation Model Alberta 1980 1995 60K was compiled from 1:60 000 scale aerial photography using analytical stereoplotters with vegetation and structures excluded. The Digital Elevation Model Northeastern Alberta 1955 1986 50K dataset was created primarily from 1:50 000 scale contour and hydrography data acquired from Natural Resources Canada (NRCAN) with supplementary aerial triangulation points derived from 1:60 000 scale black and white aerial photography dating between 1980 and 1995. The Digital Elevation Model Southwestern Alberta 1979 1996 50K dataset was created primarily from 1:50 000 scale contour and hydrography data from Natural Resources Canada, using Geographic Information System (GIS) processes that recognise the relationship between surface contours and hydrography. The Alberta Provincial Terrain is an ArcGIS terrain dataset that is built from feature classes. Terrains are TIN (Triangulated Irregular Network) -based representations of a surface and must reside inside of a geodatabase. The surface is displayed as triangles with an elevation point at the apex of each triangle. Pyramids are built into the terrain structure to generalize the display of the triangulated surface at different scales. Some analysis can be conducted using terrains but gridded data, such as a raster or a lattice, is often more useful. The Alberta Provincial Terrain is used as a base to generate the Alberta Provincial 25 and 100 Metre Rasters.

The USGS NHDPlus High Resolution service, NHDPlus_HR, a part of The National Map, is a comprehensive set of digital spatial data comprising a nationally seamless network of stream reaches, elevation-based catchment areas, flow surfaces, and value-added attributes that enhance stream network navigation, analysis, and data display. NHDPlus High Resolution (NHDPlus HR) is a scalable geospatial hydrography framework built from the high resolution National Hydrography Dataset, nationally complete Watershed Boundary Dataset, and 3D Elevation Program (3DEP) ? arc-second (10 meter ground spacing) digital elevation model data. The National Map download client allows free downloads of public domain NHDPlus HR data in Esri File Geodatabase format. For additional information on the NHDPlus HR, go to https://nhd.usgs.gov.

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 2016 and 2019 along the Florida Reef Tract (FRT) from Miami to Key West within a 939.4 square-kilometer area. USGS SPCMSC staff used seafloor elevation-change data from Fehr and others (2021) derived from an elevation-change analysis between two elevation datasets acquired in 2016/2017 and 2019 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. Due to file size limitations, the elevation-change data was divided into five blocks. A seafloor stability threshold was determined for the 2016-2019 FRT elevation-change datasets based on the vertical uncertainty of the 2016 and 2019 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 (total of 235,153,117 data points at 2-m horizontal resolution) based on the amount of erosion and accretion during the 2016 to 2019 time period. Seafloor-stability point and triangulated irregular network (TIN) surface models were created for each block 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 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 Pro map packages containing the binned and color-coded stability point and surface (TIN) models, potential coral restoration locations, and habitat files for each block; 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.

A bathymetric survey of Blue Mountain Lake, Arkansas, was conducted in May 2017 by the Lower Mississippi-Gulf Water Science Center of the U.S. Geological Survey (USGS) using methodologies for sonar surveys similar to those described by Wilson and Richards (2006). Point data from the bathymetric survey were merged with point data from an aerial LiDAR survey conducted in December 2010, for the U.S. Army Corps of Engineers (USACE), Little Rock District. From the combined point data, a terrain dataset (a type of triangulated irregular network, or TIN, model) was created in Esri ArcGIS for the lakebed within the extent of pool elevation 420 feet above the North American Vertical Datum of 1988 (NAVD88). This Esri file geodatabase contains the following products: 1) point data from the bathymetric and LiDAR surveys; 2) a terrain dataset; 3) a digital elevation model (DEM) in Esri GRID format with a 3-ft cell size; 4) a feature class of bathymetric contours at 4-ft intervals; and 5) a table of storage capacity (volume) of the lake at 1-ft increments in water-surface elevation from 350-420 ft NAVD88 and seasonal conservation and flood pool elevations.

The USGS 3D Hydrography Program (3DHP) ArcGIS REST service (3DHP_all) from The National Map is the first of several data services that will be delivered by the 3D Hydrography Program. The 3DHP_all comprises a national network of flowlines, hydrolocations, and water bodies, and will include catchments, drainage areas, and flow network derivatives as they are populated in the future. The 3DHP_all service will provide access to a 3D-enabled geospatial hydrography vector dataset built from 3DHP data and intended to provide the most comprehensive but general rendering of 3DHP data. 3DHP data is derived from elevation-derived hydrography (EDH) Elevation-Derived Hydrography Specifications | U.S. Geological Survey (usgs.gov) where available. Where EDH has not been collected, 3DHP data will be supplemented by data from the National Hydrography Dataset (NHD) National Hydrography Dataset | U.S. Geological Survey (usgs.gov). As further EDH data is collected, the EDH data will replace the NHD data in that data collection area. 3DHP data ingested from EDH sources will include catchments, drainage areas derived from catchments, and flowline network attribute derivatives.Use Constraints: _ None. All data are open and non-proprietary. However, users should be aware that temporal changes may have occurred since this dataset was collected and that some parts of this data may no longer represent actual conditions. Users should not use this data for critical applications without a full awareness of its limitations. This dataset is not intended to be used for site-specific regulatory determinations. Acknowledgment of the U.S. Geological Survey would be appreciated for products derived from these data.For additional information on the 3DHP, go to https://www.usgs.gov/3dhp.See https://apps.nationalmap.gov/help/ for assistance with The National Map viewer, download client, services, or metadata.

Los Angeles County Department of Public Works’ Vertical Control Network is composed of more than 1,700 miles (2,720 kilometers) of level runs and comprise nearly 9,000 benchmarks. The basic accuracy of the net is reflected by an indicated field probable error of ± 0.017 feet per mile (4 mm per kilometer) of leveling as determined from conditions of closure. However, because of varying degrees of subsidence and heaving, the true datum is recovered only by obtaining substantial agreement of a number of benchmarks.For each active benchmark, a point representation was created in GIS by locating them based on their description. Parcel data, mile markers, the County Address Management System (CAMS), LARIAC aerials, oblique photos, 2-foot contour lines and/or Google Street View were used in assisting with the location.The creation of the benchmarks in GIS greatly enhances the Vertical Control Network by adding visual context with respect to their representative geospatial locations. With a glance, geospatial patterns can be observed and out-of-place benchmarks can be quickly identified and remapped to the correct location after verification.To facilitate the adjustment, indexing and distribution of adjusted values in the network, the county territory was divided into 33 quads or areas. For identification purposes, each quad was given a name (for example, “Rosemead”, “La Mirada”, “Santa Fe”, and etc.). Index maps, county maps, and other information can be accessed and downloaded on the basis of each of the quads by going to Survey Division’s Benchmark Retrieval System (https://pw.lacounty.gov/sur/benchmark). General adjustments are carried out every 5 to 10 years and the provided elevation data is expected to remain sound during this period. When a quad is adjusted, new elevations will be published and the date of the readjustment will be noted. No historical data is provided, but it can be acquired from Survey Division’s Public Records Counter or via the fee based Optional Technical Research (OTR) program. For general questions, contact:Hector Chang626-458-7038hchang@dpw.lacounty.govFor survey-related questions, contact:Charles Springstun626-320-9896cspring@dpw.lacounty.govThe following resources can be used to obtain historical benchmark data:PUBLIC RECORDS COUNTER900 S. Fremont Ave, 4th FloorAlhambra, CA 918037:00 AM to 5:00 PM Mon – ThursPhone: (626) 458-5137OPTIONAL TECHNICAL RESEARCH (OTR)7:00 AM to 5:00 PM Mon – ThursPhone: (626) 458-5131

The 3D Hydrography Program (3DHP) data is an integrated, National, 3D-enabled hydrologic dataset derived from the USGS 3D Elevation Program (3DEP) data. For areas where Elevation-derived Hydrography (EDH) has not yet been collected, 3DHP data is supplemented by hydrologic vector data from the National Hydrography Dataset (NHD). As further EDH data is collected, it will replace the NHD data in those areas. 3DHP data ingested from EDH sources includes ‘value added’ catchments and flowline network derivative attributes. All the data is open and non-proprietary. However, users should be aware that temporal changes may have occurred since this dataset was collected and that some parts of this data may no longer represent actual surface conditions. Users should not use this data for critical applications without a full awareness of its limitations. This dataset is not intended to be used for site-specific regulatory determinations. 3DHP datasets include a three-dimensional (3D) hydrography network generated from, and integrated with, elevation data from the 3DEP to better represent stream gradients and channel conditions, along with waterbodies, hydrologic units, hydrologically enhanced elevation and other surfaces, and more consistent and accurate attributes. This product is new in federal fiscal year 2025 (FY25), and consists only of vector data in a series of feature classes. The product represents the 3DHP dataset and the schema in which it is contained as of September 30, 2024 Future Annual Staged Product releases will reflect the schema at the time the product is generated and include more EDH-sourced data holdings.

This dataset provides topographic indices derived from 1 m resolution DEMs for sequoia groves in both Sequoia-Kings Canyon and Yosemite National Parks. All mapped sequoia groves in Sequoia-Kings Canyon National Park and two groves from Yosemite National Park, Merced and Mariposa, are included. For each grove, aspect, slope, the stream network, height above nearest drainage (HAND), depth to water (DTW), maximum elevation deviation (DEVmax), and heat load index (HLI) are calculated. These indices were chosen because of their relevance in determining soil moisture across a landscape. Derived topographic parameters were calculated using 1 m DEMs generated in 2016 resampled to 3 m and a combination of ArcGIS Pro Tools, ArcPy Scripts, Whitebox GAT tools, and R scripts. The stream networks, which are further used in the calculation of HAND and DTW, were determined using a flow accumulation threshold of 2000 meters squared based on a literature-accepted range, chosen specifically based on ...

To assess the current topography of tidal marsh at the study sites we conducted survey-grade global positioning system (GPS) surveys between 2009 and 2014 using a Leica RX1200 Real Time Kinematic (RTK) rover (±1 cm horizontal, ±2 cm vertical accuracy; Leica Geosystems Inc., Norcross, GA; Figure 4). At sites with RTK GPS network coverage (Padilla, Port Susan, Nisqually, Siletz, Bull Island, and Bandon), rover positions were received in real time from the Leica Smartnet system via a CDMA modem (www.lecia-geosystems.com). At sites without network coverage (Skokomish, Grays Harbor, and Willapa), rover positions were received in real time from a Leica GS10 antenna base station via radio link. At sites where we used the base station, we adjusted all elevation measurements using an OPUS correction (www.ngs.noaa.gov/OPUS). We used the WGS84 ellipsoid model for vertical and horizontal positioning and referenced positions to a local National Geodetic Survey (NGS) benchmark or a benchmark established by a surveyor (Figure 4). Average measured vertical errors at benchmarks were 1-9 cm throughout the study, comparable to the stated error of the GPS. To measure topographic variation at each site, we surveyed marsh surface elevation along transects perpendicular to the major tidal sediment source, with a survey point taken every 12.5 m; 50 m separated transect lines (Appendix Figs. A1 – I1). We used the Geoid09 model to calculate orthometric heights from ellipsoid measurements (m, NAVD88; North American Vertical Datum of 1988) and projected all points to NAD83 UTM zone 10 using Leica GeoOffice v7.0.1 (Leica Geosystems Inc, Norcross, GA).In ArcGIS 10.2.1 Spatial Analyst (ESRI 2013, Redlands, CA), we created a digital elevation model (DEM) for each site using each sites survey elevation data points. We processed the elevation point data with exponential ordinary kriging methods (5 x 5 m cell size) while adjusting model parameters to minimize the root-mean-square (RMS) error to create the best model fit for the DEM (Table 2). We used elevation models as the baseline conditions for subsequent analyses including tidal inundation patterns, SLR response modeling, and mapping of sites by specific elevation (flooding) zones.

The USGS Transportation downloadable data from The National Map (TNM) is based on TIGER/Line data provided through U.S. Census Bureau and supplemented with HERE road data to create tile cache base maps. Some of the TIGER/Line data includes limited corrections done by USGS. Transportation data consists of roads, railroads, trails, airports, and other features associated with the transport of people or commerce. The data include the name or route designator, classification, and location. Transportation data support general mapping and geographic information system technology analysis for applications such as traffic safety, congestion mitigation, disaster planning, and emergency response. The National Map transportation data is commonly combined with other data themes, such as boundaries, elevation, hydrography, and structure ...

The rivers of Africa dataset is derived from the World Wildlife Fund's (WWF) HydroSHEDS drainage direction layer and a stream network layer. The source of the drainage direction layer was the 15-second Digital Elevation Model (DEM) from NASA's Shuttle Radar Topographic Mission (SRTM). The raster stream network was determined by using the HydroSHEDS flow accumulation grid, with a threshold of about 1000 km² upstream area.

The stream network dataset consists of the following information: the origin node of each arc in the network (FROM_NODE), the destination of each arc in the network (TO_NODE), the Strahler stream order of each arc in the network (STRAHLER), numerical code and name of the major basin that the arc falls within (MAJ_BAS and MAJ_NAME); - area of the major basin in square km that the arc falls within (MAJ_AREA); - numerical code and name of the sub-basin that the arc falls within (SUB_BAS and SUB_NAME); - area of the sub-basin in square km that the arc falls within (SUB_AREA); - numerical code of the sub-basin towards which the sub-basin flows that the arc falls within (TO_SUBBAS) (the codes -888 and -999 have been assigned respectively to internal sub-basins and to sub-basins draining into the sea). The attributes table now includes a field named "Regime" with tentative classification of perennial ("P") and intermittent ("I") streams.

Supplemental Information:

This dataset is developed as part of a GIS-based information system on water resources for the African continent. It has been published in the framework of the AQUASTAT - programme of the Land and Water Division of the Food and Agriculture Organization of the United Nations.

Contact points:

Data lineage:

The linework of the map was obtained by converting the stream network to a feature dataset with the Hydrology toolset in ESRI ArcGIS.The Flow Direction and Stream Order grids were derived from hydrologically corrected elevation data with a resolution of 15 arc-seconds.The elevation dataset was part of a mapping product, HydroSHEDS, developed by the Conservation Science Program of World Wildlife Fund.Original input data had been obtained during NASA's Shuttle Radar Topography Mission (SRTM).

Online resources:

Hydrological basins in Africa

This dataset provides the centreline of railway track, each polyline segment representing a KiwiRail asset record. Depiction of each main line, yard track, loop, and link, and identifies it's nearest location (using a KiwiRail location name) and asset ID number. Does not include Private Sidings or privately owned track.

This data is suitable for mapping but not for survey accurate information or exporting to CAD for design (does not include true track geometry/design or elevation).

Supplied as ESRI Feature Service (polyline) in NZTM, spatial accuracy +/- 0.5m

NOTE: for a simplified version of the track data for more generic mapping, please use the NZ Railway Network dataset.

The U.S. Geological Survey has been forecasting sea-level rise impacts on the landscape to evaluate where coastal land will be available for future use. The purpose of this project is to develop a spatially explicit, probabilistic model of coastal response for the Northeastern U.S. to a variety of sea-level scenarios that take into account the variable nature of the coast and provides outputs at spatial and temporal scales suitable for decision support. Model results provide predictions of adjusted land elevation ranges (AE) with respect to forecast sea-levels, a likelihood estimate of this outcome (PAE), and a probability of coastal response (CR) characterized as either static or dynamic. The predictions span the coastal zone vertically from -12 meters (m) to 10 m above mean high water (MHW). Results are produced at a horizontal resolution of 30 meters for four decades (the 2020s, 2030s, 2050s and 2080s). Adjusted elevations and their respective probabilities are generated using regional geospatial datasets of current sea-level forecasts, vertical land movement rates, and current elevation data. Coastal response type predictions incorporate adjusted elevation predictions with land cover data and expert knowledge to determine the likelihood that an area will be able to accommodate or adapt to water level increases and maintain its initial land class state or transition to a new non-submerged state (dynamic) or become submerged (static). Intended users of these data include scientific researchers, coastal planners, and natural resource management communities.

These GIS layers provide the probability of observing the forecast of adjusted land elevation (PAE) with respect to predicted sea-level rise or the Northeastern U.S. for the 2020s, 2030s, 2050s and 2080s. These data are based on the following inputs: sea-level rise, vertical land movement rates due to glacial isostatic adjustment and elevation data. The output displays the highest probability among the five adjusted elevation ranges (-12 to -1, -1 to 0, 0 to 1, 1 to 5, and 5 to 10 m) to be observed for the forecast year as defined by a probabilistic framework (a Bayesian network), and should be used concurrently with the adjusted land elevation layer (AE), also available from http://woodshole.er.usgs.gov/project-pages/coastal_response/, which provides users with the forecast elevation range occurring when compared with the four other elevation ranges. These data layers primarily show the distribution of adjusted elevation range probabilities over a large spatial scale and should therefore be used qualitatively.