How does the DEP erosion model work?
The Daily Erosion Project (DEP) uses a tested and proven soil erosion model (the Water Erosion Prediction Project model or WEPP) that estimates soil erosion and water runoff occurring on hill slopes. Estimates are based on hill slope conditions: for example, slope steepness, slope length, tillage used and crop growing in each field, soil type and rainfall. The conditions on each hill slope are identified from remote sensing: LiDAR for topography, satellite imagery for soil and crop management and field boundaries, NEXRAD radar for precipitation, and electronic data bases for details such as soil type. Sheet and rill soil erosion estimates are made for approximately 240,000 randomly selected hill slopes in Iowa with a similar density of hill slope erosion estimates occurring across all of the DEP coverage area. From these DEP erosion estimates, we post daily the average hill slope soil loss (and water runoff) occurring for each HUC12 watershed in the DEP coverage area.