After running my SWY, I don’t understand the results I got for base flow and quick flow. The base flow is even more fascinating. I classify the results in symbology and the values are too huge for me to understand. For the base flow (-1,340,275.63 - 2,846,626,304). The values for QF range from (0-1,492.992). Can I use the direct values for QF in my interpretation? What should I also do about the base flow values? I have attached a snapshot of the results.
The QF.tif result is the total annual quickflow runoff for each pixel, with units of millimeters. It is based mostly on precipitation and curve number, so if you have high values for precipitation, those can lead to some high values of quickflow.
As the User Guide says, B_sum.tif is “the flow through a pixel, contributed by all upslope pixels, that is not evapotranspired before it reaches the stream”. So it is very possible for this to be a large number, if there is a lot of precipitation, and/or a large upslope contributing area, and/or low evapotranspiration. If you want to see the contribution of an individual pixel to baseflow, look at B.tif.
It is ok to use the direct values of QF in your interpretation, with the caveat that we can’t feel confident in the absolute values unless we’ve compared them against observed data and calibrated the model. For baseflow, since the model is so very simplified, we recommend only using them as relative values, showing which areas are contributing more or less to baseflow.
