3. Global lakes and wetlands database


The global lakes and wetlands database GLWD





Former versions

WELAREM1 (2001)


Drawing upon a variety of existing maps, data and information, a new Global Lakes and Wetlands Database (GLWD) has been created. The combination of best available sources for lakes and wetlands on a global scale (1:1 to 1:3 million resolution), and the application of GIS functionality enabled the generation of a database which focuses in three coordinated levels on (1) large lakes and reservoirs, (2) smaller water bodies, and (3) wetlands. Level 1 (GLWD-1) comprises the shoreline polygons of the 3067 largest lakes (area ≥ 50 km2) and 654 largest reservoirs (storage capacity ≥ 0.5 km3) worldwide, and includes extensive attribute data. Level 2 (GLWD-2) comprises the shoreline polygons of permanent open water bodies with a surface area ≥ 0.1 km2 excluding the water bodies contained in GLWD-1. The approx. 250,000 polygons of GLWD-2 are attributed as lakes, reservoirs and rivers. Level 3 (GLWD-3) comprises lakes, reservoirs, rivers and different wetland types in the form of a global raster map at 30-second resolution. For GLWD-3, the polygons of GLWD-1 and GLWD-2 were combined with additional information on the maximum extents and types of wetlands. Class ‘lake’ in both GLWD-2 and GLWD-3 also includes man-made reservoirs, as only the largest reservoirs have been distinguished from natural lakes. GLWD-2 and GLWD-3 do not provide detailed descriptive attributes such as names or volumes.


GLWD-1 and GLWD-2 are distributed as ArcView polygon shapefiles while GLWD-3 is distributed as grid in ArcView/ArcInfo coverage format. Total file size of the database is about 140 MB. Fore more information regarding spatial resolutions and attributes please read the documentation.


Classification of stagnant fresh water bodies.

Data download

Alternative URL




Alternative URL




lakes, wetlands, reservoirs, surface water, fresh water, global map, hydrology

Please cite as

"Lehner, B. and Döll, P. (2004): Development and validation of a global database of lakes, reservoirs and wetlands. Journal of Hydrology 296/1-4: 1-22."