3. Create LS Raster

Description

Generates the LS parameter raster as well as the specific catchment area raster. The LS parameter originates from the Revised Universal Soil Equation or Revised Universal Soil Loss Equation (RUSLE) which is commonly used to estimate the rate of soil loss by water. The following equation is used:

A=R*K*L*S*C*PWhere:A: Mean annual soil loss (t/ha/year)

R: rainfall erosivity factorK: Soil erodibility factor

L: Slope length

S: Slope steepness

C: Landcover management factor

P: Erosion control practices (assume to be 1/none)

L*S is combined here to create the LS factor. Additionally,

LS= Power(facc * cell size / 22.1, 0.4) * Power(Sin(slp * 0.01745) / 0.09, 1.4) * 1.4

Where:

facc is the flow accumulation.

slp is the slope in degrees.

Usage

Parameters

Direction	Type	Parameter Name	Data Type	Dialog Reference
Input	Required	Input DEM	GPRasterLayer	Input elevation raster.
Output	Required	Output LS Raster	GPRasterLayer	Output LS Raster created using the equation: LS= Power(facc * cell size / 22.1, 0.4) * Power(Sin(slp * 0.01745) / 0.09, 1.4) * 1.4
Output	Required	Output Slope Raster	GPRasterLayer	Derived slope raster, in degrees.
Output	Required	Output Specific Catchment Area Raster	GPRasterLayer