Water Resources eAtlas
 

01 Primary Watersheds Map
Watersheds of the World : Global Maps

     

 

 

 

Map Description
  
This map shows the location of 114 major watersheds of the world. It includes the world’s largest transboundary watersheds and other small basins that are representative of a particular geographic area. Omitted regions, shown in white, are primarily smaller coastal drainage basins or regions with no permanent rivers. Basins are labeled and numbered by geographic region. The principal subbasins of these large watersheds are not highlighted in this map, however, profiles for each one of the subbasins are available in the CD-Rom.

 
 
 
Mapping Details
  
River basin boundaries presented in this map are based on two datasets: a revised version of the Major Watersheds of the World dataset distributed on the GlobalARC CD-ROM by the U.S. Army Corps of Engineers Construction Engineering Research Laboratories (CERL) and the EROS Data Center HYDRO1k basin boundaries developed at the U.S. Geological Survey. The CERL basins were digitally derived using ETOPO5, 5-minute gridded elevation data, and known locations of rivers. The HYDRO1k is a geographic database derived from the USGS' 30 arc-second digital elevation model of the world (GTOPO30). Because of the low resolution of the elevation data used to derive the CERL base data layer, boundaries are coarse and an effort was made to refine the basin boundaries as follows. WRI revised and checked basin boundaries by overlaying ArcWorld 1:3 million rivers. In cases where rivers (except canals) crossed basin boundaries, the boundary was edited using a 1-kilometer Digital Elevation Model as a guide and redrawing the boundaries along identifiable ridges. In some cases, polygons were split to separate subbasins. After editing the boundaries, all subbasins were identified and labeled for each primary basin, using several world atlases as references.

 
 
 
Map Projection
  
Robinson

 
 
 
Sources
  

Revenga, C., S. Murray, J. Abramovitz, and A. Hammond, 1998. Watersheds of the World: Ecological Value and Vulnerability. Washington, DC: World Resources Institute.

U. S. Geological Survey’s Hydro 1k data available at: http://edcdaac.usgs.gov/gtopo30/hydro/

 
 
   
 

 

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