Burn-in stream network and selecting DEM threshold
What is it?
Burn-in stream network allows users to reduce the DEM elevation along the burn-in lines, so that the resulting stream network matches the user stream network.DEM cell threshold is an important step in determining the number of subbasins within a watershed. Threshold is the number of cells or area required to form a stream. If a cell has at least the number of threshold cells or area draining into it, the cell will be a part of stream. Selecting lower number of threshold cells results in higher number of subbasins.
How to use it:
Burn in existing stream network
User can either use the stream file uploaded to the server or can upload a new one.To use a stream file already uploaded to the server, click "Use Uploaded File". A list of already uploaded files appear. Click on the desired file name.
To upload a new stream file, check the box next to 'Import' and click 'Import'. Browse to the desired stream file. Burn file is a shapefile.
Once a file selected, click 'Burn'. Stream network is burn in DEM and is displayed over the background map.
Define threshold
Default number of cells and area in hectares in displayed as threshold. Users can change either number of cells or area to define threshold. Lower the threshold, higher the number of subbasins and vice versa.
Once threshold is selected, click 'Create streams' to run TauDEM.