DDM30 dataset information page
|A global 30 minute drainage direction map|
Statement: Global drainage direction map
Abstract: The global drainage direction map DDM30 is a raster map which describes the drainage directions of surface water with a spatial resolution of 30’ longitude by 30’ latitude. 66896 individual grid cells, covering the entire land surface of the globe (without Antarctica), are connected to each other by their respective drainage direction and are thus organized into drainage basins. Each cell can drain only into one of the eight neighboring cells.
DDM30 is based on
- the digital drainage direction map with a resolution of 5’ of Graham et al. (1999) for South America, Australia, Asia and Greenland,
- the HYDRO1k digital drainage direction map (as flow accumulation map) with a resolution of 1 km (USGS, 1999) for North America, Europe, Africa and Oceania (without Australia).
Both given base maps were up scaled to a resolution of 30’.
|Data format:||BIL, ArcExport|
|Data resolution:||30’ longitude by 30’ latitude|
Spatial data coverage: Global (without Antarctica)
Temporal data coverage: Time snap shot
Time period covered: