Mapping watersheds invites comparisons

Computerized maps of environmental features for 154 of the largest river watersheds around the globe will soon be available to the public, free of charge. A group of research and conservation groups unveiled a draft of the interactive database at the Third World Water Forum in Japan last month. When completed, the database will be accessible through the Internet and on compact disks.

A driving force behind the project was international interest in freshwater biodiversity, notes Daniel B. Tunstall, director of information programs with the World Resources Institute in Washington, D.C., a codeveloper of the new database. Research by several organizations, including the U.N. Convention on Biodiversity, has shown that “freshwater species of fish and invertebrates are more threatened [with extinction] than any other,” he says.

The new project maps the number of known fish species within a watershed–the area drained by a river system–and the share of those species that are found only in its waters.

Other mapped features include human-population density, types of land cover, and major cities.

Tunstall expects policy makers around the globe to use the maps and data to study the natural benefits of river systems, such as flood control, recharging groundwater, supporting biodiversity, and supplying drinking water.


If you have a comment on this article that you would like considered for publication in Science News, send it to Please include your name and location.

Janet Raloff is the Editor, Digital of Science News Explores, a daily online magazine for middle school students. She started at Science News in 1977 as the environment and policy writer, specializing in toxicology. To her never-ending surprise, her daughter became a toxicologist.

More Stories from Science News on Earth