MERIT Hydro: A High‐Resolution Global Hydrography Map Based on Latest Topography Dataset

• Published in: Water resources research 2019-06, Vol.55 (6), p.5053-5073
• Main Authors: Yamazaki, Dai, Ikeshima, Daiki, Sosa, Jeison, Bates, Paul D., Allen, George H., Pavelsky, Tamlin M.
• Format: Article
• Language: English
• Subjects: Accumulation; Algorithms; Arid regions; Basins; Biogeochemical cycle; Biogeochemical cycles; Biogeochemistry; Carbon emissions; Climate models; Datasets; Digital Elevation Models; Drainage area; Drainage channels; Earth science; Elevation; Environmental risk; Equator; Flood risk; Flow; Flow mapping; Gauges; Geologic depressions; global hydrology; High water levels; Hydrography; Hydrologic cycle; Hydrologic data; Hydrology; Open systems; Resolution; Risk assessment; River basins; River channels; River hydrology; river network; River networks; Rivers; Runoff; Satellites; Spatial data; Streamlines; Streams; Surface flow; Surface water; topography; Topography (geology); Water bodies; Water levels; Water resources; Watersheds; Width
• ISSN: 0043-1397; 1944-7973
• DOI: 10.1029/2019WR024873

High‐resolution raster hydrography maps are a fundamental data source for many geoscience applications. Here we introduce MERIT Hydro, a new global flow direction map at 3‐arc sec resolution (~90 m at the equator) derived from the latest elevation data (MERIT DEM) and water body data sets (G1WBM, Global Surface Water Occurrence, and OpenStreetMap). We developed a new algorithm to extract river networks near automatically by separating actual inland basins from dummy depressions caused by the errors in input elevation data. After a minimum amount of hand editing, the constructed hydrography map shows good agreement with existing quality‐controlled river network data sets in terms of flow accumulation area and river basin shape. The location of river streamlines was realistically aligned with existing satellite‐based global river channel data. Relative error in the drainage area was