Topographic(LS) Factor

Both the Length (L) and Steepness (S) of the land slope substantially affect the rate of soil erosion by water. The effects of each of these factors have been evaluated in independent research and are represented in the soil loss (RUSLE) equation by the topographic factor (LS). LS represents the impact of slope length on erosion and is influenced by the shape and angle of the slope. An increase in the slope length and slope steepness increases erosion. The former has a greater impact than the latter. The app computes the topographic factor (LS), i.e., a ratio of soil loss from a site to that from a reference site having the same soil and slope but with a length of 22.1m. and uniform 9% grade. We use this formula = (/22.13)m * (0.065+0.046S+0.0065S2) Where is the slope length in meters and in entered by the user; S is the slope gradient expressed in %, and is also entered by the app user. M varies with the slope steepness m = 0.2 for S<1%; 0.3 for 1%==12%.