Property:Extended data description
From CSDMS
This is a property of type Text.
G
Gridded Population of the World, version 3 (GPWv3) is the latest developments in the rendering of human populations in a common geo-referenced framework, produced by the Center for International Earth Science Information Network (CIESIN) of the Earth Institute at Columbia University.
GPWv3 depicts the distribution of human population across the globe. It is the most detailed version of GPW to date with more than three times the amount of data as version 2, and includes population estimates to 2015.
Developed between 2003 and 2005, GPWv3 provides globally consistent and spatially explicit human population information and data for use in research, policy making, and communications.
GPWv3 incorporates a number of improvements to the two prior iterations of GPW. Input administrative data have been improved for nearly all of the 232 countries included in the dataset. (The number of administrative units has increased three-fold since GPWv2 and twenty-fold since GPWv1.) Additionally, the input data years have been updated for over two-thirds of the countries. The population data estimates, previously only available for 1990 and 1995, are also now provided for the period 1990–2015, by quinquennial years. The population estimates for 2005, 2010, and 2015 were produced in collaboration with the United Nations Food and Agriculture Programme (FAO) as GPW: Future Estimates. Finally, the map collection has been vastly expanded to include population density, and sub-national administrative boundary maps at country, continental, and global levels. +
H
HYDRO1k is a geographic database developed to provide comprehensive and consistent global coverage of topographically derived data sets, including streams, drainage basins and ancillary layers derived from the USGS' 30 arc-second digital elevation model of the world (GTOPO30). 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.
Developed at the U.S. Geological Survey's Center for Earth Resources Observation and Science (EROS), the HYDRO1k project's goal is to provide to users, on a continent by continent basis, hydrologically correct DEMs along with ancillary data sets for use in continental and regional scale modeling and analyses. +
HydroSHEDS is a mapping product that provides hydrographic information for regional and global-scale applications in a consistent format. It offers a suite of geo-referenced data sets (vector and raster) at various scales, including river networks, watershed boundaries, drainage directions, and flow accumulations. HydroSHEDS is based on high-resolution elevation data obtained during a Space Shuttle flight for NASA's Shuttle Radar Topography Mission (SRTM).
The goal of developing HydroSHEDS was to generate key data layers to support regional and global watershed analyses, hydrological modeling, and freshwater conservation planning at a quality, resolution and extent that had previously been unachievable. Available resolutions range from 3 arc-second (approx. 90 meters at the equator) to 5 minute (approx. 10 km at the equator) with seamless near-global extent. +
I
International Bathymetric Chart of the Arctic Ocean (IBCAO). The goal of this initiative is to develop a digital data base that contains all available bathymetric data north of 64 degrees North, for use by mapmakers, researchers, and others whose work requires a detailed and accurate knowledge of the depth and the shape of the Arctic seabed.
IBCAO Version 3.0 represents the largest improvement since 1999 taking advantage of new data sets collected by the circum-Arctic nations, opportunistic data collected from fishing vessels, data acquired from US Navy submarines and from research ships of various nations. Built using an improved gridding algorithm, this new grid is on a 500 meter spacing, revealing much greater details of the Arctic seafloor than IBCAO Version 1.0 (2.5 km) and Version 2.0 (2.0 km). The area covered by multibeam surveys has increased from ~6 % in Version 2.0 to ~11% in Version 3.0. +
G
Latest version (5.0)
The latest version of the "Global Map of Irrigation Areas" is version 5, which can be downloaded from this page. The documentation of the map includes an explanation of the methodology, information per country, an assessment of the map quality, and references to the background and history of the irrigation mapping project.
The map shows the amount of area equipped for irrigation around the year 2005 in percentage of the total area on a raster with a resolution of 5 minutes. Additional map layers show the percentage of the area equipped for irrigation that was actually used for irrigation and the percentages of the area equipped for irrigation that was irrigated with groundwater, surface water or non-conventional sources of water. An explanation of the different terminology to indicate areas under irrigation is given in this glossary. Please note that information for the additional layers on area actually irrigated or on the water source for irrigation was derived from statistical survey data (e.g. census reports). Therefore all grid cells belonging to the same statistical unit will have the same value. Consequently, the accuracy at pixel level will be very limited, depending on the size of the statistical unit.
Users are requested to refer to the map as follows: "Stefan Siebert, Verena Henrich, Karen Frenken and Jacob Burke (2013). Global Map of Irrigation Areas version 5. Rheinische Friedrich-Wilhelms-University, Bonn, Germany / Food and Agriculture Organization of the United Nations, Rome, Italy". +
M
Layers (NetCDF) of monthly and yearly average suspended sediment flux in global rivers, predicted by the WBMsed model. +
G
Lithology describes the geochemical, mineralogical, and physical properties of rocks. It plays a key role in many processes at the Earth surface, especially the fluxes of matter to soils, ecosystems, rivers, and oceans. The Lithological map of the World is based on the Global Lithological Map database v1.1 (GLiM, Hartmann and Moosdorf, 2012). GLiM represents the rock types of the emerged surface of the Earth using 1,235,400 polygons assembled from 92 regional geological maps, translated into lithological units using additional literature. According to the GLiM, the total surface of continents and islands is covered by 64 % sediments (a third of which is carbonates), 13% metamorphics, 7% plutonics, and 6% volcanics, and 10% are covered by water or ice. The high resolution of the GLiM allows observation of regional lithological distributions which often vary from the global average. The GLiM enables regional analysis of Earth surface processes at global scales. A coarse gridded version of the GLiM is available at the PANGEA Database (http://dx.doi.org/10.1594/PANGAEA.788537), the original GIS data are downloadable using this link (https://www.dropbox.com/s/9vuowtebp9f1iud/LiMW_GIS%202015.gdb.zip?dl=0). +
P
Multiple general circulation models were run for paleoclimate simulations at 21, 6, and 0 (pre-inudstrial) ka. +
N
NARWidth is composed of planform morphometric measurements of North American rivers at approximately mean discharge. It was created using image processing algorithms on Landsat TM and ETM+ imagery. NARWidth is intended to be used in a wide variety of scientific and engineering applications including hydrologic, hydraulic, and biogeochemical models. +
G
NGDC is the US national archive for multibeam bathymetric data and presently holds over 15.7 million nautical miles of ship tracklines (1187 surveys) received from sources worldwide.
In addition to deepwater data, the multibeam database also includes hydrographic multibeam survey data from the NOS. Associated NOS data products, including 3D images and grids, are available via the NOS Hydrographic Survey Data Map Service. +
M
NGDC's GEODAS Marine Trackline Geophysics database contains bathymetry, magnetics, gravity and seismic navigation data collected during marine cruises from 1953 to the present. Coverage is worldwide. Data sources include both US and foreign oceanographic institutions and government agencies.
This database is distributed both On-line and on DVD using the GEODAS Search and Retrieval software. Searches by geographic area, year of cruise, institution, platform, cruise, date or parameter are available. Downloads can be customized to area, parameter and format.
Digital data files are in the MGD77 exchange format, and contain a documentation header record and a series of data records. Header records document the content and structure of the data records. Data records contain geophysical data (bathymetry, magnetics, gravity and seismic shot-point ids) with time and position.
NGDC also archives analog geophysical data including seismic reflection and refraction, side-scan sonar, and other data types. Analog underway geophysical data are inventoried and searchable through the GEODAS Search and Retrieval software.
NGDC is pleased to accept contributions of underway geophysical data on almost any media, preferably in the MGD77 format. Any data received are in the international public domain, readily available globally to any interested individual or group. +
G
NOAA was engaged in a program to compile Great Lakes bathymetric data and make them readily available to the public, especially to the communities concerned with Great Lakes science, pollution, coastal erosion, response to climate changes, threats to lake ecosystems, and health of the fishing industry. This program was managed by NGDC and relied on the cooperation of NOAA/Great Lakes Environmental Research Laboratory, NOAA/National Ocean Service, the Canadian Hydrographic Service, other agencies, and academic laboratories.
Compilation of new bathymetry for the Great Lakes was an important part of this program, carried out cooperatively between NOAA (NGDC and GLERL), and the Canadian Hydrographic Service. This new bathymetry provided a more detailed portrayal of lakefloor topography, and revealed some lakefloor features seen for the first time. +
C
NOAA's National Centers for Environmental Information (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.
Bathymetric, topographic, and shoreline data used in DEM compilation are obtained from various sources, including NCEI, the U.S. National Ocean Service (NOS), the U.S. Geological Survey (USGS), the U.S. Army Corps of Engineers (USACE), the Federal Emergency Management Agency (FEMA), and other federal, state, and local government agencies, academic institutions, and private companies. DEMs cell size ranges from 1/9 arc-second (~3 meters) to 36 arc-seconds (~1 km). +
H
On-line access to information on historical (archived) water levels and streamflow. Using map-based or text-based searches, users can locate over 1200 hydrometric stations measuring water levels and view hydrographs of historical waer level and streamflow data.
Alternatively, users can use a separate tool to select and access historical data from over 2500 active stations and 5500 discontinued stations. In addition, a third tool allows users to generate historical water level and/or streamflow statistics for any of these (more than) 8000 stations. +
O
OneGeology's aim is to create dynamic digital geological map data for the world. It is an international initiative of the geological surveys of the world who are working together to achieve this ambitious and exciting venture. Please follow the links in this section to find out more about OneGeology, what it is, why we are doing it and how such a big initiative can be achieved. +
A
Presented are four companion digital models of the age, age uncertainty, spreading rates and spreading asymmetries of the world's ocean basins as geographic and Mercator grids with 2 minute resolution. The grids include data from all the major ocean basins as well as detailed reconstructions of back-arc basins. The age, spreading rate and asymmetry at each grid node is determined by linear interpolation between adjacent seafloor isochrons in the direction of spreading. Ages for ocean floor between the oldest identified magnetic anomalies and continental crust are interpolated by geological estimates of the ages of passive continental margin segments. The age uncertainties for grid cells coinciding with marine magnetic anomaly identifications, observed or rotated to their conjugate ridge flanks, are based on the difference between gridded age and observed age. The uncertainties are also a function of the distance of a given grid cell to the nearest age observation, and the proximity to fracture zones or other age discontinuities. Asymmetries in crustal accretion appear to be frequently related to asthenospheric flow from mantle plumes to spreading ridges, resulting in ridge jumps towards hotspots. We also use the new age grid to compute global residual basement depth grids from the difference between observed oceanic basement depth and predicted depth using two alternative age-depth relationships. The new set of grids helps to investigate prominent negative depth anomalies, which may be alternatively related to subducted slab material descending in the mantle or to asthenospheric flow. A combination of our digital grids and the associated relative and absolute plate motion model with seismic tomography and mantle convection model outputs represent a valuable set of tools to investigate geodynamic problems. +
R
RESSED is a Microsoft® Access ® database containing information from the original Soil Conservation Service (SCS) datasheets (SCS Form 34) for the United States. The database is provided for download (i.e., this website does not contain tools for utilizing the RESSED database). The Subcommittee on Sedimentation hopes to provide updates to this database via periodic postings on this site. Such database improvements may be predicated on acquisition of adequate funding for RESSED.
Additionally, scanned copies of the original data sheets are available for selected viewing, downloading, or printing. The data sheets are in Adobe® Acrobat® Portable Document Format (PDF). +
S
Sage contains a compilation of monthly mean river discharge data for over 3500 sites worldwide. The data sources are RivDis2.0, the United States Geological Survey, Brazilian National Department of Water and Electrical Energy, and HYDAT-Environment Canada. The period of record for each station is variable, from 3 years to greater than 100. All data is in m3/s. +
T
TPXO6.2 is a medium-resolution, 1/4o x 1/4o global model developed by Gary Egbert and coworkers at Oregon State University. The model domain includes ocean cavities under the floating ice shelves. The principal assimilated data set is TOPEX/Poseidon (T/P) satellite radar altimetry, between +/-66o latitude. However, the model also includes patches for various "coastal" oceans, including the Antarctic (assimilating tide gauge data used in circum-Antarctic inverse model CADA00.10 and the Ross Sea height-based inverse model Ross_Inv_2002, and the Arctic (cf. the Arctic inverse model AOTIM-5). TPXO6.2 is one of the most accurate global tidal solutions, particularly for high latitudes since it utilizes recent Antarctic grounding line information and Antarctic and Arctic tide height data.
The load tide associated with TPXO6.2 (denoted "TPXO62_load") is a correction to TPXO6.2 to account for the deformation of the solid earth due to the added weight of water above it. The correction is usually a few percent of the local tidal amplitude. The load tide is used to correct the ocean tide to a geocentric tide height (e.g., the displacement of the ocean's free surface as measured by a satellite altimeter. The load tide is roughly out-of-phase with the ocean tide. Thus, adding the predicted load tide to the ocean tide leads to smaller tide heights. For altimetry, this means that the altimetrically-observed tide-forced variation of, say, an ice shelf surface, is typically less than the ocean tide. The load tide (or, more precisely, the "ocean self attraction and loading" term), is also required to correct the barotropic pressure gradient (i.e., sea surface slope) in the shallow water wave equations used to run dynamically based tide models.
The load tide is not the same as the earth's own body-tide response to lunar and solar gravitation: the body tide must be estimated separately from solid-earth models if required. However, the load tide is defined under continents as well as under the ocean: ocean tides force deformation of the earth's crust well inland of the coastal boundary (see the above figure).
TPXO62_load is distributed with a Matlab Graphical User Interface ("GUI") called "TMD" (the Tide Model Driver). TMD can be used to quickly access and browse the model, and to make load tide height predictions. The TMD package also contains scripted functions for use in batch-mode Matlab processing. For an overview of the GUI and scripts, view or download the README PDF file. For FORTRAN access, please go to the Oregon State "OTIS" web page.
TRMM, during its mission and broad sampling footprint between 35°N and 35°S, is providing some of the first detailed and comprehensive dataset on the four dimensional distribution of rainfall and latent heating over vastly undersampled oceanic and tropical continental regimes. Combined with concurrent measurement of the atmosphere's radiation budget, estimates of the total diabatic heating are being realized for the first time ever on a global scale.
TRMM will fill many gaps in our understanding of rainfall properties and their variation. These includes:
# frequency distributions of rainfall intensity and areal coverage;
# the partitioning of rainfall into convective and stratiform categories;
# the vertical distribution of hydrometeors (including the structure and intensity of the stratiform region bright band);
# variation of the timing of heaviest rainfall - particularly nocturnal intensification of large mesoscale convective systems over the oceans, and diurnal intensification of orographically and sea-breezed forced systems over land.
TRMM will enable mapping of larger time and space variations of rainfall in quasi-periodic circulation anomalies, such as the Madden-Julian oscillation in the western Pacific and ENSO over the broader Pacific basin. +
N
The 3 arc-second U.S. Coastal Relief Model (CRM) provides the first comprehensive view of the U.S. coastal zone, integrating offshore bathymetry with land topography into a seamless representation of the coast. The CRM spans the U.S. East and West Coasts, the northern coast of the Gulf of Mexico, Puerto Rico, and Hawaii, reaching out to, and in places even beyond, the continental slope.
Bathymetric data sources include the U.S. National Ocean Service Hydrographic Database, the U.S. Geological Survey (USGS), the Monterey Bay Aquarium Research Institute, the U.S. Army Corps of Engineers, and various other academic institutions. Topographic data are from the USGS and the Shuttle Radar Topography Mission (SRTM). Volumes 3 through 5 also use bathymetric contours from the International Bathymetric Chart of the Caribbean Sea and the Gulf of Mexico project. +
C
The CGIAR-CSI GeoPortal is able to provide SRTM 90m Digital Elevation Data for the entire world. The SRTM digital elevation data, produced by NASA originally, is a major breakthrough in digital mapping of the world, and provides a major advance in the accessibility of high quality elevation data for large portions of the tropics and other areas of the developing world. The SRTM digital elevation data provided on this site has been processed to fill data voids, and to facilitate it's ease of use by a wide group of potential users. This data is provided in an effort to promote the use of geospatial science and applications for sustainable development and resource conservation in the developing world. Digital elevation models (DEM) for the entire globe, covering all of the countries of the world, are available for download on this site. The SRTM 90m DEM's have a resolution of 90m at the equator, and are provided in mosaiced 5 deg x 5 deg tiles for easy download and use. All are produced from a seamless dataset to allow easy mosaicing. These are available in both ArcInfo ASCII and GeoTiff format to facilitate their ease of use in a variety of image processing and GIS applications. Data can be downloaded using a browser or accessed directly from the ftp site. +
D
The Dartmouth Flood Observatory uses orbital remote sensing to detect, measure, and map river discharge and river flooding.
Water discharge is measured by the River Watch processor, based on a feed of NASA AMSR-E satellite microwave data. It produces a remote sensing signal that tracks river discharge at 2500+ carefully selected river measurement sites.
Flooding is monitored by the MODIS sensors, to map floods as they occurred. +
E
The Data Catalog is a place to discover experimental datasets. Here, you can find metadata (following standardized Dublin Core guidelines) to maximize discoverability of your experimental datasets or use search for existing datasets based on metadata categories. +
G
The GIMMS (Global Inventory Modeling and Mapping Studies) data set is a normalized difference vegetation index (NDVI) product available for a 25 year period spanning from 1981 to 2006. The data set is derived from imagery obtained from the Advanced Very High Resolution Radiometer (AVHRR) instrument onboard the NOAA satellite series 7, 9, 11, 14, 16 and 17. This is an NDVI dataset that has been corrected for calibration, view geometry, volcanic aerosols, and other effects not related to vegetation change. +
The GRDC is an international archive of data up to 200 years old, and fosters multinational and global long-term hydrological studies. Originally established two decades ago, the aim of the GRDC is to help earth scientists analyse global climate trends and assess environmental impacts and risks. Positioned as a facilitator for exchanges between data providers and data users, the GRDC has become a focal point for international cooperation. Researchers, universities and other organisations make use of the facilities available for research programmes and projects.
The Global Runoff Database at GRDC is a unique collection of river discharge data collected at daily or monthly intervals from more than 7300 stations in 156 countries. This adds up to around 280 000 station-years with an average record of 38 years. The GRDC provides discharge data and data products for non-commercial applications.
The GRDC operates under the auspices of the World Meteorological Organisation (WMO) and supports research on global climate change and integrated water resources management. The German Federal Institute of Hydrology (Bundesanstalt für Gewässerkunde or BfG) hosts the GRDC in Koblenz near the confluence of the Moselle and Rhine Rivers. +
The GSHHG is a high-resolution geography data set, amalgamated from two databases in the public domain: World Vector Shorelines (WVS) and CIA World Data Bank II (WDBII). The former is the basis for shorelines while the latter is the basis for lakes, although there are instances where differences in coastline representations necessitated adding WDBII islands to GSHHG. The WDBII source also provides political borders and rivers. GSHHG data have undergone extensive processing and should be free of internal inconsistencies such as erratic points and crossing segments. The shorelines are constructed entirely from hierarchically arranged closed polygons.
GSHHG combines the older GSHHS shoreline database with WDBII rivers and borders, available in either ESRI shapefile format or in a native binary format. Geography data are in five resolutions: crude(c), low(l), intermediate(i), high(h), and full(f). Shorelines are organized into four levels: boundary between land and ocean (L1), boundary between lake and land (L2), boundary between island-in-lake and lake (L3), and boundary between pond-in-island and island (L4). +
The Global Human Settlement Layer (GHSL) project is supported by European Commission, Joint Research Center and Directorate-General for Regional and Urban Policy. The GHSL produces new global spatial information, evidence-based analytics, and knowledge describing the human presence in the planet. The GHSL relies on the design and implementation of new spatial data mining technologies allowing to process automatically and extract analytics and knowledge from large amount of heterogeneous data including: global, fine-scale satellite image data streams, census data, and crowd sources or volunteering geographic information sources. Spatial data reporting objectively and systematically about the presence of population and built-up infrastructures are necessary for any evidence-based modelling or assessing of i) human and physical exposure to threats as environmental contamination and degradation, natural disasters and conflicts, ii) impact of human activities on ecosystems, and iii) access to resources. The project produces thematic information and evidence-based analytical knowledge supporting the implementation of EU regional urban policy and the 4 international post-2015 frameworks, namely: Sustainable Development Goals, Global Urban Agenda, Climate Change and the Sendai Framework for Disaster Risk Reduction. Also, the project supports international scientific partnerships facilitating science-policy interface in the frame of the Group of Earth Observation (GI-21: Human Planet Initiative https://www.earthobservations.org/activity.php?id=51 ), and bi-lateral scientific collaborations with space agencies and scientific organizations of Brazil, China and South Africa.
This data package contains an assessment of the REGIOOECD “degree of urbanization” model using as input the population GRID cells in four epochs (2015, 2000, 1990, and 1975). +
The Global Seismic Hazard Assessment Program (GSHAP) was launched in 1992 by the International Lithosphere Program (ILP) with the support of the International Council of Scientific Unions (ICSU), and endorsed as a demonstration program in the framework of the United Nations International Decade for Natural Disaster Reduction (UN/IDNDR).
In order to mitigate the risk associated to the recurrence of earthquakes, the GSHAP promotes a regionally coordinated, homogeneous approach to seismic hazard evaluation; the ultimate benefits are improved national and regional assessments of seismic hazards, to be used by national decision makers and engineers for land use planning and improved building design and construction. +
H
The HWSD is a 30 arc-second raster database with over 16000 different soil mapping units that combines existing regional and national updates of soil information worldwide (SOTER, ESD, Soil Map of China, WISE) with the information contained within the 1:5 000 000 scale FAO-UNESCO Soil Map of the World (FAO, 19711981).
The resulting raster database consists of 21600 rows and 43200 columns, which are linked to harmonized soil property data. The use of a standardized structure allows for the linkage of the attribute data with the raster map to display or query the composition in terms of soil units and the characterization of selected soil parameters (organic Carbon, pH, water storage capacity, soil depth, cation exchange capacity of the soil and the clay fraction, total exchangeable nutrients, lime and gypsum contents, sodium exchange percentage, salinity, textural class and granulometry).
26 March, 2009 - Version 1.1 now includes SOTER/SOTWIS data for The Democratic Republic of the Congo, Burundi, Rwanda, Senegal, and Gambia.
Reliability of the information contained in the database is variable: the parts of the database that still make use of the Soil Map of the World such as North America, Australia, West Africa and South Asia are considered less reliable, while most of the areas covered by SOTER databases are considered to have the highest reliability (Central and Southern Africa, Latin America and the Caribbean, Central and Eastern Europe). +
The HydroLAKES database was designed as a digital map repository to include all lakes with a surface area of at least 10 ha. Version 1 comprises the shoreline polygons of 1,427,688 individual lakes. HydroLAKES aims to be as comprehensive and consistent as possible at a global scale and contains both freshwater and saline lakes, including the Caspian Sea, as well as human-made reservoirs and regulated lakes. The HydroLAKES database was created by compiling, correcting, and unifying several near-global and regional datasets, foremost the SRTM Water Body Data (SWBD; Slater et al., 2006) for regions from 56˚S to 60˚N, and CanVec (Natural Resources Canada, 2013) for most North American lakes. Map generalization methods were applied and some polygon outlines were smoothed during the mapping process to ensure spatial consistency of the data. The resulting map scale is estimated to be between 1:100,000 and 1:250,000 for most lakes globally, with some coarser ones at 1:1 million. +
I
The ICE-5G (VM2) model mathematically analyses glacio-isostatic adjustment processes and provides model data on global ice sheet coverage, ice thickness and paleotopography at 10 min spatial resolution for 21ka and 0ka, and at 1degree spatial resolution for intervals in between these snapshots. These are NETCDF files. +
N
The Indian National River Linking Project (NRLP), or Indian Rivers Interlinking project (IRI), proposes a major redistribution of water resources over the Indian subcontinent. A large engineering effort is proposed to redistribute monsoonal water from the Himalayas and foothills, store water in reservoirs, and route it via canals ("links") to the drier regions of Southern India. A total of 29 links and 43 dams and barrages are proposed as part of the project.
The plan would provide water resources for agriculture, drinking water and industrial use to a growing population in central and southern India, while potentially improving flood control in the northern and mountainous areas. The project would also result in a major reorganization of watersheds, with possible impacts on ecosystems and the environment. There would be impacts on trans-boundary rivers.
Here provided are two databases: (1) the dams database, with locations, operating specifications, sources, and notes on population expected to be displaced; and (2) the canals database, with locations, operating specifications, and further notes. The databases are available as shapefiles for GIS visualization - click a feature to see its database information. A "rivers" shapefile is also available for help in generating visualizations. Note that the rivers are not currently labeled in the shapefile. Raw txt/csv format is also available for the canals and dams databases. An annotated reference list is included to give specifics on the sources from which each number was obtained and/or calculated.
The databases are constructed from hundreds of government reports, geo-referenced maps, planning and design documents and Open Street Map data. For full methodology and calculations regarding displaced populations, see the accompanying manuscript: Higgins et al., 2017. For the graph database tool used to calculate basin connectivity changes and water discharge changes for given river mouths, see the github page: https://github.com/sahiggin/NRLP .
M
The MERIT DEM was developed by removing multiple error components (absolute bias, stripe noise, speckle noise, and tree height bias) from the existing spaceborne DEMs (SRTM3 and AW3D). It represents the terrain elevations at a 3sec resolution (~90m at the equator), and covers land areas between 90N-60S. The data is freely available for research and education purpose. +
N
The Multi-Resolution Land Characteristics Consortium (MRLC) has completed the National Land Cover Database (NLCD) 2001 products for the conterminous United States, Hawaii, Alaska and Puerto Rico at 30 m cell resolution. The NLCD 2001 products (land cover, impervious surface and canopy density) were generated from a standardized set of data layers mosaicked by mapping zone. Typical zonal layers included multi-season Landsat 5 and Landsat 7 imagery centered on a nominal collection year of 2001, and Digital Elevation Model based derivatives at 30 meters spatial resolution. NLCD 2001 used an improved classification algorithm from NLCD 1992, resulting in a more precise rendering of spatial boundaries between 16 classes of land cover (additional classes are available in coastal areas and Alaska only). +
The National Elevation Dataset (NED) is the primary elevation data product of the USGS. The NED is a seamless dataset with the best available raster elevation data of the conterminous United States, Alaska, Hawaii, and territorial islands. The NED is updated on a nominal two month cycle to integrate newly available, improved elevation source data. All NED data are public domain. The NED is derived from diverse source data that are processed to a common coordinate system and unit of vertical measure. NED data are distributed in geographic coordinates in units of decimal degrees, and in conformance with the North American Datum of 1983 (NAD 83). All elevation values are in meters and, over the conterminous United States, are referenced to the North American Vertical Datum of 1988 (NAVD 88). The vertical reference will vary in other areas. NED data are available nationally (except for Alaska) at resolutions of 1 arc-second (about 30 meters) and 1/3 arc-second (about 10 meters), and in limited areas at 1/9 arc-second (about 3 meters). In most of Alaska, only lower resolution source data are available. As a result, most NED data for Alaska are at 2-arc-second (about 60 meters) grid spacing. Part of Alaska is available at the 1- and 1/3-arc-second resolution, and plans are in development for a significant improvement in elevation data coverage of the state. +
The National Hydrography Dataset (NHD) is the surface-water component of The National Map. The NHD is a comprehensive set of digital spatial data that represents the surface water of the United States using common features such as lakes, ponds, streams, rivers, canals, streamgages, and dams. Polygons are used to represent area features such as lakes, ponds, and rivers; lines are used to represent linear features such as streams and smaller rivers; and points are used to represent point features such as streamgages and dams. Lines also are used to show the water flow through area features such as the flow of water through a lake. The combination of lines is used to create a network of water and transported material flow to allow users of the data to trace movement in downstream and upstream directions. +
The National Ocean Service (NOS) Hydrographic Data Base (NOSHDB), maintained by NGDC in conjunction with NOS, provides extensive survey coverage of the coastal waters and Exclusive Economic Zone (EEZ) of the United States and its territories. The NOSHDB contains data digitized from smooth sheets of hydrographic surveys completed between 1851 and 1965, and from survey data acquired digitally on NOS survey vessels since 1965.
Over 76 million soundings from over 6600 surveys are now included in the NOSHDB. These data may be searched and downloaded online using the Hydrographic Survey Data Map Service (an interactive map and data discovery tool at NGDC; http://map.ngdc.noaa.gov/website/mgg/nos_hydro/viewer.htm). The NOSHDB data with search and retrieval software are also available on a DVD-ROM or CD-ROM set.
Data products from NOS surveys, including BAG files, descriptive reports (DRs), smooth sheet images, survey data images, textual gridded data, and sidescan sonar mosaics, are available for download from NGDC using the Hydrographic Survey Data Map Service. +
S
The Natural Resources Conservation Service (NRCS) - National Cartography and Geospatial Center (NCGC) previously archived and distributed the State Soil Geographic (STATSGO) Database. The STATSGO spatial and tabular data were revised and updated in 2006. STATSGO has been renamed to the U.S. General Soil Map (STATSGO2). It is available for download from the Soil Data Mart (http://soildatamart.nrcs.usda.gov/).
The dataset was created by generalizing more detailed soil survey maps. Where more detailed soil survey maps were not available, data on geology, topography, vegetation, and climate were assembled, together with Land Remote Sensing Satellite (LANDSAT) images. Soils of like areas were studied, and the probable classification and extent of the soils were determined.
Map unit composition was determined by transecting or sampling areas on the more detailed maps and expanding the data statistically to characterize the whole map unit.
This dataset consists of geo-referenced vector and tabular digital data. The map data were collected in 1- by 2-degree topographic quadrangle units and merged into a seamless national dataset. It is distributed in state/territory and national extents. The soil map units are linked to attributes in the tabular data, which give the proportionate extent of the component soils and their properties.
The tabular data contain estimated data on the physical and chemical soil properties, soil interpretations, and static and dynamic metadata. Most tabular data exist in the database as a range of soil properties, depicting the range for the geographic extent of the map unit. In addition to low and high values for most data, a representative value is also included for these soil properties. +
P
The PSMSL was established in 1933, and is the global data bank for long term sea level change information from tide gauges. The PSMSL collect data from several hundred gauges situated all over the globe. As of December 2006, the database of the PSMSL contains over 55000 station-years of monthly and annual mean values of sea level from almost 2000 tide gauge stations around the world received from almost 200 national authorities. On average, approximately 2000 station-years of data are entered into the database each year. +
S
The SRTM Water Body Data files are a by-product of the data editing performed by the National Geospatial-Intelligence Agency (NGA) to produce the finished SRTM Digital Terrain Elevation Data Level 2 (DTED® 2). In accordance with the DTED® 2 specification, the terrain elevation data have been edited to portray water bodies that meet minimum capture criteria. Ocean, lake and river shorelines were identified and delineated. Lake elevations were set to a constant value. Ocean elevations were set to zero. Rivers were stepped down monotonically to maintain proper flow. After this processing was done, the shorelines from the one arc second (approx. 30-meter) DTED® 2 were saved as vectors in ESRI 3-D Shapefile format.
In most cases, two orthorectified image mosaics (one for ascending passes and one for descending passes) at a one arc second resolution were available for identifying water bodies and delineating shorelines in each 1 x1 cell. These were used as the primary source for water body editing. The guiding principle for this editing was that water must be depicted as it was in February 2000 at the time of the shuttle flight. A Landcover water layer and medium-scale maps and charts were used as supplemental data sources, generally as supporting evidence for water identified in the image mosaics. Since the Landcover water layer was derived mostly from Landsat 5 data collected a decade earlier than the Shuttle mission and the map sources had similar currency problems, there were significant seasonal and temporal differences between the depiction of water in the ancillary sources and the actual extent of water bodies in February 2000 in many instances. In rare cases, where the SRTM image mosaics were missing or unusable, Landcover was used to delineate the water in the SRTM cells. The DTED® header records for those cells are documented accordingly. +
The SSURGO database contains information about soil as collected by the National Cooperative Soil Survey over the course of a century. The information can be displayed in tables or as maps and is available for most areas in the United States and the Territories, Commonwealths, and Island Nations served by the USDA-NRCS. The information was gathered by walking over the land and observing the soil. Many soil samples were analyzed in laboratories. The maps outline areas called map units. The map units describe soils and other components that have unique properties, interpretations, and productivity. The information was collected at scales ranging from 1:12,000 to 1:63,360. More details were gathered at a scale of 1:12,000 than at a scale of 1:63,360. The mapping is intended for natural resource planning and management by landowners, townships, and counties. Some knowledge of soils data and map scale is necessary to avoid misunderstandings. +
The Shuttle Radar Topography Mission (SRTM) obtained elevation data on a near-global scale to generate the most complete high-resolution digital topographic database of Earth between 56 degrees south and 60 degrees north latitude. SRTM consisted of a specially modified radar system that flew onboard the Space Shuttle Endeavour during an 11-day mission in February of 2000.
NASA has released version 2 of the Shuttle Radar Topography Mission digital topographic data (also known as the "finished" version). Version 2 is the result of a substantial editing effort by the National Geospatial Intelligence Agency and exhibits well-defined water bodies and coastlines and the absence of spikes and wells (single pixel errors), although some areas of missing data ('voids') are still present. The Version 2 directory also contains the vector coastline mask derived by NGA during the editing, called the SRTM Water Body Data (SWBD), in ESRI Shapefile format.
Version 2.1 is a recalculation of the SRTM3 (nominal 90 meter sample spacing) version made by 3x3 averaging of the full resolution edited data. Version 2 had been generated by masking in edited samples from the lower-resolution publicly released by the NGA, and contained occasional artifacts, and in particular a slight vertical “banding” in databeyond 50° latitude. These have been eliminated in Version 2.1
SRTM data are distributed in two levels: SRTM1 (for the U.S. and its territories
and possessions) with data sampled at one arc-second intervals in latitude and
longitude, and SRTM3 (for the world) sampled at three arc-seconds. Three arc-second data are generated by three by three averaging of the one arc-second samples. +
The Southern Alaska Coastal Relief Model is a 24 arc-second digital elevation model ranging from 170° to 230° and 48.5° to 66.5° N. It integrates bathymetry and topography to represent Earth's surface and spans over the Gulf of Alaska, Bering Sea, Aleutian Islands, and Alaska's largest communities: Anchorage, Fairbanks, and Juneau. The relief model was built from a variety of source datasets acquired from the National Geophysical Data Center, National Ocean Service, United States Geological Survey, National Aeronautics and Space Administration, and other U.S. and international agencies.
The CRM provides a framework to enable scientists to model tsunami propagation and ocean circulation. In addition, it may be useful for benthic habitat research, weather forecasting, and environmental stewardship. +
R
The U.S. Geological Survey Real-Time Permafrost and Climate Monitoring Network in Arctic Alaska is a collaborative effort with BLM, U.S. Fish and Wildlife Service, private organizations and universities, all managed by USGS.
The network was established to provide high quality real-time environmental data to aid in land management decision making.
This real-time network is a subset of a larger U.S. Geological Survey permafrost and climate monitoring research network. Many of the stations are co-located with deep boreholes, thus forming the basis for comprehensive permafrost monitoring observatories. The objectives of the larger network include climate change detection, monitoring how permafrost and vegetation respond to climate change, and acquiring improved data for current permafrost characterization and impact assessment models. +
N
The United States Geological Survey (USGS) has collected water-resources data at approximately 1.5 million sites across the United States, Puerto Rico, and Guam.
The types of data collected are varied, but generally fit into the broad categories of surface water and ground water. Surface-water data, such as gage height (stage) and streamflow (discharge), are collected at major rivers, lakes, and reservoirs. Ground-water data, such as water level, are collected at wells and springs.
Water-quality data are available for both surface water and ground water. Examples of water-quality data collected are temperature, specific conductance, pH, nutrients, pesticides, and volatile organic compounds.
This web site serves current and historical data. Data are retrieved by category of data, such as surface water, ground water, or water quality, and by geographic area. Subsequent pages allow further refinement by selecting specific information and by defining the output desired.
Real-time data typically are recorded at 15-60 minute intervals, stored onsite, and then transmitted to USGS offices every 1 to 4 hours, depending on the data relay technique used. Recording and transmission times may be more frequent during critical events. Data from real-time sites are relayed to USGS offices via satellite, telephone, and/or radio and are available for viewing within minutes of arrival. (Note that all real-time data are provisional and subject to revision). +
W
The World Glacier Inventory contains information for over 100,000 glaciers through out the world. Parameters within the inventory include geographic location, area, length, orientation, elevation,and classification of morphological type and moraines. The inventory entries are based upon a single observation in time and can be viewed as a 'snapshot' of the glacier at this time. The core of this collection is data from the World Glacier Monitoring Service, Zurich. The development of the data product was funded through NOAA's Environmental Services Data and Information Management (ESDIM) program. +
The World Ocean Atlas 2001 (WOA01) contains ASCII data of statistics and objectively analyzed fields for one-degree and five-degree squares generated from World Ocean Database 2001 observed and standard level flagged data.
The ocean variables included in the atlas are: in-situ temperature, salinity, dissolved oxygen, apparent oxygen utilization, percent oxygen saturation, dissolved inorganic nutrients (phosphate, nitrate, and silicate), chlorophyll at standard depth levels, and plankton biomass sampled from 0 - 200 meters. +
The World Vector Shoreline (WVS) is a digital data file at a nominal scale of 1:250000, containing the shorelines, international boundaries and country names of the world. The World Vector Shoreline is a standard US Defense Mapping Agency (DMA) product that has been designed for use in many applications. The WVS is divided into ten ocean basin area files. Together the ten files form a seamless world, with the exception of Central America, where there is an overlap between the Western North Atlantic file and the Eastern North Pacific File.
The main source material for the WVS was the DMA's Digital Landmass Blanking (DLMB) data which was derived primarily from the Joint Operations Graphics and coastal nautical charts produced by DMA. The DLMB data consists of a land/water flag file on a 3 by 3 arc-second interval grid. This raster data set was converted into vector form to create the WVS. For areas of the world not covered by the DLMB data (e.g. the Arctic and Antarctic), the shoreline was taken from the best available hard copy sources at a preferred scale of 1:250000. The WVS data are stored in chain-node format, and include tags to indicate the landside/waterside of the shoreline. +
G
The basic concept adopted to develop this database is to integrate the best land cover data available, from local to global, into one single database using international standards; this task requires the harmonization among different layers and legends to create a consistent product.
Here are criteria and steps for the harmonization:
* absorb, overcome and minimize the thematic and spatio-temporal differences between individual databases;
* create an efficient and practical mechanism to harmonize various datasets using the land cover elements;
* use data fusion techniques to overcome some of the harmonization issues;
identify agreement/disagreement between a limited number of global dataset at pixel level;
* create land cover database;
* validate land cover database;
* develop a fully automated “procedure” to update the database when new datasets may become available. +
