Global Lakes and Wetlands Database

The global lakes and wetlands database GLWD has been developed in partnership with the Center for Environmental Systems Research, University of Kassel, Germany. It is available for download as three separate ArcView layers (two polygon shapefiles and one grid). The files have been compressed using WinZip and are 46 MB in total size. The database consists of (1) large lakes and reservoirs, (2) smaller water bodies, and (3) wetlands. The first level comprises shoreline polygons of 3067 of the largest lakes (>=50 km**2) and 654 of the largest reservoirs (storage capacity >=0.5 km**3) worldwide. The second level comprises the shoreline polygons of permanent open water bodies with a surface area >=0.1 km**2. The 250,000 polygons in Level 2 are attributed to lakes, reservoirs and rivers. Level 3 comprises lakes, reservoirs, rivers and wetlands at 30-second resolution. According to the GLWD, lakes and reservoirs cover a total of approximately 2.7 million km**2 or 2.0% of the global land surface area, while wetlands are about 8-10 million km**2 or 6.2-7.6%. Data Sources used include: - MSSL Global Lakes Database (Birkett and Mason, 1995) - Large Reservoirs (Vorosmarty, et al. 1997) - World Register of Dams (ICOLD, 1998) - Digital Chart of the World, hydrography layer (ESRI, 1993) - ArcWorld 1:3M hydrography layer (ESRI, 1992) - WCMC Global Wetlands Map (WCMC, 1993) - Global Land Cover Characterization (Loveland, et al, 2000)