ESTIMATING SOIL EROSION AND DEPOSITION UNDER FUTURE CLIMATE AND LAND COVER CHANGE SCENARIO – USPED MODEL APPLICATION IN THE MISSISSIPPI PLAINS

We used the Unit Stream Power - based Erosion Deposition (USPED) models, together with modeled future land cover and climate data to estimate the lateral movement of soils on the Mississippi Alluvial Plain and Valley Loess Plains, USA.

Land cover maps from FORE-SCE model (250m resolution, used to generate the Cover factor for the USPED), SRTM DEM data (90m resolution), STATSGO soil erodibility map (K factor), and CGCM2 climate data (10km resolution, IPCC SREA A2) were used to simulate 2001–2050 soil erosion and deposition across the region. The major purpose of this model application is to calculate the sediment supply for river systems.

Major adjustments were made for the USPED application: 1) a land cover weight layer was used in the surface flow accumulation calculation for USPED so that a more realistic transport capacity could be obtained, 2) a carbon factor was used to convert soil erosion to C erosion, and 3) an average distance of C movement was defined and derived from the flow accumulation value, which was used to calculate the SOC oxidation loss to the atmosphere during the lateral movement of eroded material.