DAILY ESTIMATES OF SOIL EROSION AND RUNOFF IN IOWA

The largest water quality impairment in the Midwest US is farmland sediment. Yet few understand the severity or impact of erosion. The project objective is to estimate, at the township level (~10 X 10 km), daily soil erosion and runoff for Iowa and to deliver a map to the public showing daily soil erosion estimates. WEPP, a daily simulation model, is used to compute soil erosion and surface runoff. WEPP uses break point precipitation obtained by Doppler radar and other weather data from an Iowa Weather network. The National Resources Inventory data points provide soils, topography, cropping and soil management information required for running WEPP. Daily estimates illustrate a high level of spatial variability in runoff and erosion related to topography, rainfall characteristics, soils and crop management practices.