I am trying to use QGIS to assess what areas will flood if the river floods a specific height. I have a DEM of the area as well as a vector file of the lines of the river of interest. I cannot get a raster file of the river height. Is there any way to do this?
4
-
You might check with these folks: hatarilabs.com– Stu SmithApr 6, 2021 at 1:44
-
1Could you please clarify what you mean by "areas will flood if the river floods a specific height.". If it is a flat water level, you can simply just mark the area in the DEM that fills to that level. However most river systems are a bit more complex than that, youll likely have a slope and varying levels in tributaries.– itsguptaApr 6, 2021 at 3:21
-
For example if the river level rises 1 foot, what will flood, I can't just fill the DEM to a set level because the river does not run at a constant elevation– Connor StackApr 6, 2021 at 18:22
-
Search for HAND - height above nearest drainage.– FelixIPSep 17, 2021 at 2:48
Add a comment
|
1 Answer
If you have GRASS enabled in your processing toolbox, you can use r.lake. This method takes a DEM, a water level and a starting point as input. The output is a raster map with the flooded area.
-
It is clear from tool name that this tool is wrong one for river flooding.– FelixIPSep 17, 2021 at 2:45