SE.HY sub-basins, watersheds

A catchment area is the area from which water is drained upstream of a certain point. The catchment area is bounded by hill backs, which divide the flow from rain and melt water in different directions. The watershed is the limit of the catchment area.For a river basin, the water flow in the outlet can be calculated using information about the area, land, lakes, watercourse lengths, precipitation, evaporation, snow storage, etc. Sub-basins usually refer to the finest subdivision into river basins, but the word sub-basin can in principle mean an arbitrary part of a larger river basin. The product, based on version SVAR 2016:6, contains 53 538 polygons representing Swedish sub-basins and Swedish islands in the sea. A subset of the Norwegian and Finnish sub-basins is also included in the product. Supply description of sub-basins: https://opendata-download.smhi.se/svar/SVAR_Basprodukter_2016_6.pdf