What is DEP?

The Daily Erosion Project (DEP) estimates soil erosion and water runoff occurring on hill slopes in Iowa and surrounding states. Estimates are based on hill slope conditions (e.g. topography, crop, precipitation) identified via remote sensing tools like satellites. The DEP team then posts daily estimates of average hill slope soil loss (and water runoff) occurring for each watershed in the DEP coverage area. 

Why does erosion matter?

Soil erosion is the movement of soil particles down and from sloping land. These moving soil particles reduce soil productivity and degrade water quality.  Soil erosion thins and can completely remove topsoil, the soil layer richest in organic matter and plant nutrient concentration. These lost nutrients must be replaced for crop production purposes, adding extra cost in addition to lost crop yield potential.

The WEPP Model

WEPP is an erosion prediction model useful in small watersheds (field-sized) and can simulate up to large fields, mimicking the natural processes important in soil erosion. Everyday it updates the soil and crop conditions that affect soil erosion. When rainfall occurs, the plant and soil characteristics are used to determine if surface runoff will occur, then the program will ccalculate estimated erosion.