World Wildlife Fund

WASHINGTON - A team of scientists from World Wildlife Fund (WWF) has developed data and created maps of the world's rivers that provide researchers with a host of valuable information about where streams and watersheds occur on the earth's landscape and how water drains the land surface. The new product, known as HydroSHEDS, provides this information globally at a resolution and quality never before available. The product is based on newly available high-resolution elevation data obtained during NASA's Shuttle Radar Topography Mission (SRTM). HydroSHEDS stands for "Hydrological data and maps based on SHuttle Elevation Derivatives at multiple Scales."

Although high-quality river maps exist for individual rivers and even entire nations, there is a lack of seamless high-quality data on global and continental scales. Data for many international river basins are patchy, and remote areas are often poorly mapped. For some regions of the world, such as the Congo Basin in Africa and parts of the Amazon Basin in South America, HydroSHEDS will provide the first high-resolution digital river maps produced for these large areas. Importantly, these previously poorly mapped systems are often those of exceptionally high conservation interest.

At the most basic level, HydroSHEDS will allow scientists to create digital river and watershed maps. These maps can then be coupled with a variety of other datasets or applied in computer simulations, such as hydrologic models that estimate flow regimes. The kind of hydrographic information provided by HydroSHEDS allows scientists and managers to perform analyses ranging from basic watershed delineation to sophisticated flow modeling.

"With HydroSHEDS, scientists will have foundational information for understanding poorly explored watersheds, and that will invariably advance conservation," said Bernhard Lehner, conservation hydrologist with WWF's Conservation Science Program and the project leader of HydroSHEDS. "WWF has already applied HydroSHEDS to classify parts of the Amazon headwaters, an area where no high-resolution river maps existed. The effort allowed researchers to begin classifying aquatic habitats, a high priority in an ecoregion where very little is known about species occurrences and distributions."

HydroSHEDS developers expect a wide range of scientists will use the data. For instance, taxonomists will ultimately be able to link their field site locations directly to digital river maps. In the future, WWF researchers also hope to use HydroSHEDS to assess the possible impacts of climate change on freshwater ecosystems.

HydroSHEDS was developed by the Conservation Science Program of World Wildlife Fund, in partnership with the U.S. Geological Survey, the International Center for Tropical Agriculture, The Nature Conservancy, and the Center for Environmental Systems Research of the University of Kassel, Germany, and with the support of JohnsonDiversey. JohnsonDiversey is a leading provider of cleaning and sanitation products and solutions to the commercial marketplace.

South America is the first continent for which data are completed. Other continents will be available over the course of the next year.

HydroSHEDS data are freely available for non-commercial use and can be accessed at: www.worldwildlife.org/hydrosheds or http://hydrosheds.cr.usgs.gov