DDM30 dataset information page

Short Description

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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

  1. the digital drainage direction map with a resolution of 5’ of Graham et al. (1999) for South America, Australia, Asia and Greenland,
  2. 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

Data type: Hydrography
Data origin: Modeled
Data format: BIL, ArcExport
Other format:
Data resolution: 30’ longitude by 30’ latitude

Data Coverage

Spatial data coverage: Global (without Antarctica)
Temporal data coverage: Time snap shot
Time period covered:


Download data: Water Modeling/DDM30/index.html
Data source: