20230308 17045400 1.0 TRUE Global Sub-Basins (level 4) All HydroBASINS layers were derived from World Wildlife Fund’s HydroSHEDS data based on a grid resolution of 15 arc-seconds (approximately 500 m at the equator). Watersheds were delineated in a consistent manner at different scales, and a hierarchical sub-basin breakdown was created following the topological concept of the Pfafstetter coding system. The resulting polygon layers are termed HydroBASINS and represent a subset of the HydroSHEDS database. This shapefile contains (sub-)basin polygons for Siberia at Pfafstetter level 4. The HydroBASINS product has been developed on behalf of World Wildlife Fund US (WWF), with support and in collaboration with the EU BioFresh project, Berlin, Germany; the International Union for Conservation of Nature (IUCN), Cambridge, UK; and McGill University, Montreal, Canada. We kindly ask users to cite HydroBASINS in any published material produced using the data. If possible, online links to the HydroSHEDS website (http://www.hydrosheds.org) should be provided. Citations and acknowledgements of the HydroBASINS data should be made as follows: Lehner, B., Grill G. (2013): Global river hydrography and network routing: baseline data and new approaches to study the world’s large river systems. Hydrological Processes, 27(15): 2171–2186. Data is available at www.hydrosheds.org.