Prediction of Sediment Yield from Southern Plains Grasslands with the Modified Universal Soil Loss Equation

Abstract

Amounts of sediment per runoff event from grassland watersheds in the Texas Blackland Prairie, Southern High Plains, Central Rolling Red Prairies, and Central Rolling Red Plains land resource areas of Oklahoma and Texas were predicted using the modified Universal Soil Loss Equation (MUSLE). In this equation, Y = 11.8(Qqp)^0.56 KCPSL where Y = sediment yield in metric tons, Q = runoff volume in m3, qp = peak runoff rate in m3/sec, K = soil erodibility factor, C = crop management factor, P = erosion control-practice factor, and SL = slope length, gradient factor. Periods of study were 3 to 5 years and included treatments involving grazing density, fertilization, cultivation, and burning. Over the range of watersheds, average measured sediment yield varied from less than 10 to more than 800 kg/ha/event. In most cases, the predicted values compared favorably to the field measured values.