The National Soil Erosion Research Laboratory

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WEPP is expected to become a major component of the "conservation toolkit." It is a computer program designed to be employed by the same personnel currently using USLE. By analyzing how farming and land use affect soil erosion and sediment delivery, WEPP promises better conservation planning, better project planning, and optimum resource inventory and assessment. It will help users select the best erosion control practices, aid in choosing optimum locations for future project sites, and evaluate erosion and sedimentation over specified areas. There are several other programs used to predict soil erosion.

WEPP is a process-oriented, continuous simulation, erosion prediction model. It is applicable to small watersheds (field-sized) and can simulate small profiles (USLE types) up to large fields. It mimics the natural processes that are 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. If predicted, then the program will compute estimated sheet & rill detachment and deposition, and channel detachment and deposition.

The WEPP model includes a number of conceptual components which are used to predict and calculate these estimates of soil detachment and deposition.

They include:


1.  Climate - (Rainfall, Parameters, Temperature, Solar Radiation, Wind)



2.  Winter - (Freeze - Thaw, Snow Accumulation, Snow Melting)



3.  Irrigation - (Stationary Sprinkler, Furrow)



4.  Hydrology - (Infiltration, Depressional Storage, Runoff)



5.  Water Balance - (Evapotranspiration, Percolation, Drainage)



6.  Soils - (Types and Properties)


7.  Crop Growth - (Cropland, Rangeland, Forestland)



8.  Residue Management and Decomposition


9.  Tillage Impacts On Infiltration and Erodibility


10.  Erosion - (Interrill, Rill, Channel)



11.  Deposition - (Rills, Channels, and Impoundments)



12.  Sediment Delivery, Particle Sorting and Enrichment


WEPP can be applied at the field scale to simulate single hillslope erosion or more complex watershed scale erosion:

Hillslope Applications
Watershed Applications

To insure that the WEPP model code was applicable to a wide range of conditions Field experiments conducted. 

The history of the WEPP project is outlined.

The WEPP video archive can be found here.


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