Provides an analysis of the state of the world's river basins, including the environmental goods and services they provide. PDF profiles with maps, data, and indicators for 154 of the world's largest basins are available online.

Executive Summary

This report for the first time presents and analyzes a wide range of global data at the watershed level, assessing 154 watersheds around the world. The analysis focuses on watershed, as ecological units and on the risks of degradation from human activities, which may undermine their ability to provide ecological services and maintain intact the biodiversity found within them. The analysis is based on 15 global indicators that characterize watersheds according to their value, current condition, and vulnerability to potential degradation. These indicators, presented in more than 150 maps, give a unique global perspective on the largess transboundary watersheds, as well as many smaller basins and sub-basins.

Watershed Boundaries

River basin boundaries 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. The resulting basin boundaries are from Revenga, C., S. Murray, J. Abramovitz, and A. Hammond, 1998. Watersheds of the World: Ecological Value and Vulnerability. Washington, DC: World Resources Institute.

Copyright, acknowledgements and license agreement

The Watersheds of the World CD is a collaborative product of four organizations: IUCN-The World Conservation Union, the International Water Management Institute (IWMI), the Ramsar Convention Bureau, and the World Resources Institute (WRI).

Research, data compilation and map production

Carmen Revenga, Project Manager (WRI)
Janet Nackoney, GIS Analyst (WRI)
Eriko Hoshino, Research Analyst (WRI)
Yumiko Kura, Research Analyst (WRI)
Jon Maidens, Data Analyst (WRI)

CD Production and Design:
Elroy Bos: Project Coordinator (IUCN)
Leonard Chabloz: Graphic Designer (Independent Consultant)

Published by:

IUCN, IWMI, Rasmar Convention Bureau and WRI
World Resources Institute
10 G Street NE
Washington, DC 20002
© 2003 World Resources Institute. All rights reserved.
ISBN: 1-56973-548-8

License agreement:

IMPORTANT! By using the Watersheds of the World_CD, you agree to the following provisions. If you do not agree with these provisions, return the materials to the World Resources Institute within three days of receipt.

The Information and the CD on which the information is contained are licensed to you, the end-user, for your own personal or internal institutional value. You do not obtain title to the intellectual property embodied on the CD or any copyrights or proprietary rights to such contents. You may not transfer, sublicense, rent, lease, convert, copy, modify or translate the copyrighted materials contained therein.

The enclosed data, information and maps are provided "as is." All warranties and representations of any kind with regard to the contents of this CD are herby disclaimed, including the implied warranties of merchantability and fitness for a particular purpose. Under no circumstances will the World Resources Institute, IUCN-The World Conservation Union, the International Water Management Institute or the Ramsar Convention Bureau be liable for any consequential, incidental, special, or exemplary damages resulting from use of the software. Some states do not allow the limitation of exclusion of liability for incidental or consequential damages, so the above limitation or exclusion may not apply to you.


IUCN, IWMI, Ramsar and WRI would like to thank the Netherlands’ Ministry of Foreign Affairs, the Water and Nature Initiative of IUCN, the Challenge Program on Water and Food, and the Comprehensive Assessment of Water Management in Agriculture for their in-kind and financial support to the project.

Special thanks go to the following institutions that provided key data and information: BirdLife International, Conservation International’s Center for Applied Biodiversity Science, the Species Survival Commission of IUCN, and Wetlands International.

The authors would also like to thank the following colleagues and collaborators for their contributions and support: Dan Tunstall (WRI), Ger Bergkamp (IUCN), David Molden (IWMI), Upali Amarasinghe (IWMI), Delmar Blasco (Ramsar), Nick Davidson (Ramsar), Ania Grobicki (Challenge Program on Water and Food), Mike Evans (BirdLife International), Simon Stuart (SSC/CABS), Janice Long (CI/CABS), Rob Waller (CI/CABS), Scott Fraizer (Wetlands International), Ellen Amting (Wetlands International), Ximing Cai (IFPRI), David Dole (River Murray Water), David Coates (Bangladesh Fourth Fisheries Project), and Theo Visser.