Hydrologic processes and the resulting phenomena are studied and reported in logic „water” units at local, regional, national or international levels. A catchment is commonly recognised as the abstract unit of study and reporting in hydrology, the basin as the physiographic unit where hydrologic processes take place. Determined by the topographical and geological conditions, a basin is bounded by a watershed (line). Within the basin, all waters flow to a common outlet, which is determined by the lowest point on the bounding watershed. Geometrically, a basin may be described by its bounding watershed and a planar basin area.
The widespread use of GIS in hydrology and environmental sciences, led to an increasing demand for basin polygons. The evaluation of our user statistics confirms this, since shapefiles are supplied with around 75% of all requests. In 2011 Prof. Bernhard Lehner, Associate Professor in the Department of Geography of McGill University in Canada, derived more than 7500 watersheds that were represented in the Global Runoff Database at that time. The GRDC remains grateful for his work and for the permission to make available the generated watershed polygons to the users of the GRDC data set. The HydroSHEDS (Hydrological data and maps based on SHuttle Elevation Derivatives at multiple Scales) drainage network (Lehner et al., 2008a) offers the unique opportunity to generate watershed boundaries for GRDC gauging stations using a proofed dataset and applying a consistent methodology that is published as Report 41 in the GRDC Report Series.
Meanwhile the station number has been increased to over 10,000 stations. For the new stations the watershed boundary was derived, so that currently about 97% of all GRDC gauging stations have a shapefile. In order to be able to compare the calculations, the methodology has been adopted with slightly changes from the previous product of Prof. Bernhard Lehner, which is described below. The smaller deviations refer to the manual procedure where the comparison of the long-term annual discharge is no longer considered. Additionally, for smaller catchments that the HydroSHEDS dataset could not represent appropriately, the new HydroSHEDS v1 (Lehner et al., 2008b) was used, which has a higher resolution of 3 arc-second (~90m).
Acknowledgments:
HydroSHEDS version 1 has been developed by World Wildlife Fund (WWF), in partnership or collaboration with McGill University, Montreal, Canada; the U.S. Geological Survey (USGS); the International Centre for Tropical Agriculture (CIAT); The Nature Conservancy (TNC); the Australian National University, Canberra, Australia; and the Center for Environmental Systems Research (CESR), University of Kassel, Germany. Major funding for this project was provided to WWF by Diversey Holdings, Ltd.; additional financial support was provided by The Nature Conservancy, the International Union for Conservation of Nature (IUCN), the EU BioFresh project, and McGill University.
Recommended citation:
GRDC (2023): Watershed Boundaries of GRDC Stations / Global Runoff Data Centre. Koblenz, Germany: Federal Institute of Hydrology (BfG).
Download:
The Watershed Boundaries of GRDC Stations are provided as GEOJSON files from the GRDC Data Portal (download all stations in monthly format) or can be accessed in the following formats:
| Format |
|---|
| Shapefile (ZIP, 44MB) |
| GEOJSON (ZIP, 52MB) |