The Global Lakes and Wetlands Database (GLWD) includes the best available data sources and GIS functionality for global lakes and wetlands focused on three scales (1) large lakes and reservoirs, (2) smaller water bodies, and (3) wetlands. The map scaless provided range from 1:1 to 1:3 million resolution. Level 1 (GLWD-1) comprises the 3,067 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 permanent open water bodies with a surface area ≥ 0.1 km2 excluding the water bodies contained in GLWD-1. Level 3 (GLWD-3) comprises lakes, reservoirs, rivers and different wetland types in the form of a global raster map at 30-second resolution.
