Hi, i'm using the follow equation to create an LS factor for RUSLE, if anyone has used a similar equation did they divide the output by 10 or 100?
LS = Power(FlowAccumulation * 50 / 22.1, 0.4) * Power(Sin(Slope * 0.01745) / 0.09, 1.4) * 1.4
It has been used in studies [1,2] and my results seem more accurate when dividing by 10.
Thanks.
[1] Prasannakumar, V., Vijith, H., Abinod, S., Geetha, N. 2012. Estimation of soil erosion risk within a small mountainous sub-watershed in Kerala, India using Revised Universal Soil Loss Equation (RUSLE) and geo-information technology. Geoscience Frontiers, 3(2), pp. 209-215.
[2] Parveen, R., Kumar, U. 2012. Integrated Approach of Universal Soil Loss Equation (USLE) and Geographical Information System (GIS) for Soil Loss Risk Assessment in Upper South Koel Basin, Jharkhand. Journal of Geographic Information System. 4, pp. 588-596.
This comment has arisen before
https://community.esri.com/message/254894#comment-254894
You would be advised to go through all the threads on GeoNet using ... usle or rusle as key word searches
There are many and most come down to using the wrong formulation for slope (ie in degrees or % rise), if the slope is given as %rise (% change) then an obvious division by 100 would make sense to get rid of the % sign. Check the original references to and those on GeoNet to see how universal the expression is.
The original Slope raster was in degrees, however it is converted to radians in the equation. I originally divided by 100 so may stick with that.
why did you divide it with 100? can you please be more specific.