User:Abenk
Automatically Calculating USLE using GISus-M
What is USLE
The Universal Soil Loss Equation (USLE) allows one to calculate the long-term average soil erosion rates for mainly agricultural lands. When calculating the USLE, five major factors must be taken into consideration:
A = R * K * LS * C * P
Where:
A is the potential long-term erosion rate in tonnes per hectare
R is the rainfall run off factor
K is the soil erodibility factor
LS is the slope length-gradient factor
C is the crop factor
P is the conservation practices factor
Classically, the LS factor was estimated by hand, with complex slopes being broken down into segments. However with the advent of high-resolution open source data, such as South-Western Ontario Orothophotography (SWOOP), LS factor can be calculated through computational means. SWOOP 2010 has a resolution of 20cm and a horizontal accuracy of 50cm, and as such is suitable for calculating the USLE.
GISus-M
GISus-M was created by the Universidade Federal do Reconcavo da Bahia, and is an add-in for ArcMap that is written in C#. To use the add-in, the user must run the ESRIADDIN file that is contained in the .rar archive. To run GISus-M in ArcMap, one must have prepared all the requisite files for calculating USLE, namely, a raster representing the R, K, LS, and C factors - the P factor is optional and can be included with the C factor.
