Entropy Approach in Investigating The Interaction Between Human Disturbance and Soil Erosion

Arid and semi-arid watersheds are susceptible to soil erosion for the lack of vegetation and the spatially/temporarily uneven precipitation. Human disturbance, such as grazing, effectively decreases the available vegetation and aggravate the situation. Although the interaction between erosion and human disturbance has been speculated for a long time, its numerical relationship is still obscure in a large scale because other factors, such as scale and topography, also get involved. In the current research, we will use the entropy approach to modulate the erosion of soil in the tributaries of Cowhouse Creek in central Texas. The observation data from the 33 subwatersheds of Cowhouse Creek will be used to validate the modulation. We will try to combine the effects of eroding probability and reinfiltration probability in the entropy theory and compare the predicted result with our observations. The eroding probability will be affected by human disturbance, land use, topography, and climate. The reinfiltration probability will be affected by topography alone. The topography information will be extracted from a DEM (digital elevation model) model. The difference in soils will not be considered in the current research. The magnitude of effects from human disturbance can then be isolated for cases with different scale and topography. The significance of human disturbance for different subwatersheds will be presented.