SE.HY sub-basins; View service

River basins are demarcated by watersheds and one or more outlets. If a river basin is defined for an outlet point within an existing river basin this is how sub-basins are formed. An outlet for a sub-area then becomes the entry point for the downstream compartment. Water bodies are abstract boundaries that are made after height information. Water parts is created in map data at the highest possible locations starting at selected outlet locations so the creation of a demarcated area upstream; It is assumed that precipitation flows off at different directions at a watershed, as if the water drains on the ground or as if: the watershed continues vertically into the ground. For a water catchment area, the water flow in the outlet can be calculated using: information about the area, land, lakes, watercourse lengths, precipitation, evaporation, snow storage etc. The product contains 52358 polygons representing sub-basins that together: covers the whole of Sweden.