The acquisition of digital maps is the first step for an Arc Hydro data model implementation. As any GIS system The Arc Hydro data model is also based on a set of thematic layers as main ingredients of the spatial dataset. The new information age has brought not only increasing computing power but also an abundance of digital data availability from different sources world wide. Below you will find a diverse list of sources of digital information with specialized emphasis, quality, resolution, and coverage of the earth.

Besides getting your specific digital maps for an Arc Hydro implementation it is important to know how to relate your digital maps with the standard Arc Hydro feature classes contained in  the data model design. Below you will find a list of Arc Hydro feature classes with its associated digital maps from well known sources of information in the U.S. For your preliminary implementation of the Data Model you may focus of the underlined layers listed below.

• Watershed
  • Description: A tessellation of a basin into drainage areas selected for a particular management purpose.
  • Possible source: http://nhd.usgs.gov, from NHDinArc or NHDinGeo format
• Waterbody
  • Description: Areal water features.
  • Possible source: region.rch layer from NHDinArc, http://nhd.usgs.gov
• MonitoringPoint
  • Description: A permanent monitoring site (gages, stations, etc.)
  • Possible source: NSIP, layer name: al_sites_geo9_point. Only USGS active stream gages (8-digit codes) also from Hydro-Climatic Data Network (HCDN) http://water.usgs.gov/pubs/wri/wri934076/region12.html
• HydroEdge
  • Description: Complex edge feature representing a line in the Hydro Network.
  • Possible source: route.drain layer from NHDinArc, http://nhd.usgs.gov
• HydroPoint
  • Description: Any point feature of hydrologic interest for the water balance, control, and regulation. In Arc Hydro there are 7 types of hydropoints including WaterWithdrawal (diversions) and WaterDischarge (return flows).
  • Possible source: From TCEQ, Control Points representing water right features (diversion points, return flow points, etc.) on the network and for each water right permit. It may contain WP parameters & NextDownIDs used in the WAM model in Texas.
• Catchment
  • Description: Tessellation of a basin into elementary drainage areas defined by topographic rules. (D-8 Algorithm, thresholds, etc.)
  • Possible source: USGS-EDNA layer called CATCH, http://edna.usgs.gov/ or your own DEM derived catchments.

Take a look at the websites below to see if some provide the base maps needed for your specific project! For the main core of the Arc Hydro Data Model you will normally need the underlined layers listed above.

Digital Data Sources for GIS and Water Resources

Data for the United States

Hydrologic Unit Maps (HUC)

Description http://water.usgs.gov/GIS/huc.html

Get the data http://water.usgs.gov/lookup/getspatial?huc250k

The 8-digit hydrologic cataloging units are the basic water resources subdivision of the United States

EPA Reach File 1 (RF1)

Description http://water.usgs.gov/GIS/metadata/usgswrd/erf1.html

Get the data http://water.usgs.gov/lookup/getspatial?erf1

EPA Basins Model

Description http://www.epa.gov/OST/BASINS/

Get the data http://www.epa.gov/OST/BASINS/gisdata.html

Contains a large inventory of environmental data organized by 8-digit hydrologic cataloging units

National Hydrography Dataset (NHD)

Description http://nhd.usgs.gov

Get the data http://nhd.usgs.gov/data.html

NHD Applications Symposium, Dec 2000 http://www.crwr.utexas.edu/giswr/events/122000nhda/

The stream network and water bodies of the United States organized by 8-digit hydrologic cataloging units

National Inventory of Dams http://crunch.tec.army.mil/nid/webpages/nid.cfm

Digital Elevation Models (DEMs) for the United States

USGS Geographic Data Download http://edc.usgs.gov/geodata/

Seamless data distribution from EROS Data Center http://seamless.usgs.gov/

1 arc-second cells (1:24,000 scale) National Elevation Dataset http://edcnts12.cr.usgs.gov/ned/

Other USGS DEM data http://edc.usgs.gov/Webglis/glisbin/guide.pl/glis/hyper/guide/usgs_dem

Elevation Derivatives for National Applications (EDNA) http://edcnts12.cr.usgs.gov/ned-h/index.html

National Severe Storms Laboratory Basin Delineation project NSSL National Basin Delineation Project

US Coastline from National Geophysical Data Center

Coastline Extractor http://rimmer.ngdc.noaa.gov/coast/

USDA Soils Data

Statsgo – State Soil Database (1:250,000 scale) http://www.ftw.nrcs.usda.gov/stat_data.html

Ssurgo – County Soil Database http://www.ftw.nrcs.usda.gov/ssur_data.html

Statsgo is available for the whole United States.  Ssurgo is much more detailed but is available only in some counties.  For an exercise on how to interpret Statsgo, see: http://www.ce.utexas.edu/prof/maidment/giswr98/statland/webfiles/viewstat.htm

Land Use/Land Cover Data

USGS Land Use/Land Cover (LULC) http://nsdi.usgs.gov/products/lulc.html

National Wetlands Inventory Center http://www.nwi.fws.gov/

National Land Cover Dataset

Description http://edcwww.cr.usgs.gov/programs/lccp/nationallandcover.html

Get the data http://edcwww.cr.usgs.gov/pub/edcuser/vogel/states/

National Atlas of the United States http://www.nationalatlas.gov/atlasftp.html

The LULC files have been the standard land use/land cover dataset of the US but are now being superseded by fresh mapping in the National Land Cover Dataset.

Climate

USDA Water and Climate Center (PRISM maps of mean precipitation) http://www.ftw.nrcs.usda.gov/prism/prism.html

National Climate Data Center http://www.ncdc.noaa.gov/

For an exercise using PRISM and land cover data to estimate nonpoint source pollution, see: http://www.ce.utexas.edu/prof/maidment/giswr98/nonpoint/webfiles/corpus.html

Water Resources

USGS National Water Information System http://water.usgs.gov/usa/nwis/

Real Time USGS Data on Water Watch http://water.usgs.gov/nwis/rt

Texas Data

Texas Natural Resource Information System http://www.tnris.state.tx.us/

TNRIS Vector Data http://www.tnris.state.tx.us/DigitalData/data_cat.htm

Global Data

ESRI Geography Network http://www.geographynetwork.com/

Digital Chart of the World http://www.maproom.psu.edu/dcw/

Geocommunity website  http://gisdatadepot.com/catalog/

GTOPO30 - 30 arc-second cell (1:1,000,000 scale) global DEM http://edcdaac.usgs.gov/gtopo30/gtopo30.html

Hydro1K – hydrologic derivative datasets from GTOPO30 http://edcdaac.usgs.gov/gtopo30/hydro/index.html

EROS Data Center Gateway http://edcimswww.cr.usgs.gov/pub/imswelcome/

Global Water and Energy Experiment (GEWEX) http://www.gewex.org/

For other useful web links, see: http://www.ce.utexas.edu/prof/maidment/gishydro/docs/websites/othr_web.htm

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