Elevation (Water Overlay)
The terrain height defines the height of the terrain on and in which the hydrology is modeled. Terrain height includes the relief on the surface of dry land, but also the height of the stream beds of water bodies. Additionally, the height of constructions is also taken into account to form the Digital Surface Model the Water Module calculates with.
By default the terrain height model will be derived from data sources relevant to the geographical location of the project area. However, especially in water bodies the level of detail of the terrain height may be insufficient. For these situations it's possible to load in a(n additional) GeoTiff of terrain heights, load in a GeoJSON file with water depths, or manually modify the elevation model.
During a session, a number of actions can directly affect the terrain height. Actions such as the creation of levees, or the creation of open water, both affect the topography. Placing or removing constructions also affects the terrain height, in terms of where water can flow.