How do I choose an appropriate Stream Area Threshold (SAT)?
There are some research studies that suggest typical values for SAT in particular geographic areas based on empirical measurements or erosional investigations. To use these values for generation of stream networks you will need to convert them from area to number of pixels by dividing the area by pixel area (pixel height x pixel width). However, it can also be useful to vary the SAT value significantly and generate stream networks and associated hydrologic parameters at many different scales. If you observe differences in parameters over project subcatchments that are consistently evident at a number of different SAT values then this is good evidence that these subcatchments may have a different rainfall response which should be taken into account in any further hydrologic or hydraulic modelling.
