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Water Erosion Prediction Project

Water Erosion Prediction Program (WEPP) predicts water erosion with a process-based, distributed parameter, continuous simulation, model for use on personal computers running Windows 95/98/NT/2000/XP/Vista/Windows7.

WEPP is available for use by conservation planners in situations where its advanced functionality such as soil erosion and water management risk statistics, conservation system effectiveness in wet and dry years, and soil hydrology are desired.  NRCS regional and state agronomists can assist planners in the use of WEPP.  The WEPP model computes both sheet and rill erosion detachment and deposition on various types of hillslopes, as well as the total sediment delivery to the end of the slope along with water budget information.  
WEPP is available on the world wide web and is compatible with Google Chrome, or Firefox browsers.  It accesses a national cloud-based database for soils, climate, crops, operations and other data needed for all model sub processes. Model and database updates or downloads are automated.  

WEPP is a process-based, continuous simulation, deterministic model that has seven process-based sub models including:  Soil, Climate, Management, Hydrology, Plant Growth, Residue Decomposition, and Erosion.  

Daily climate is generated by CLIGEN which produces individual storm parameter estimates, including time to peak, peak intensity, and storm duration over a 100 year simulation period.  Additionally when using the digital map feature, PRISM automatically adjusts climate including temperature and precipitation to actual latitude and longitude of the site.  

A modified EPIC plant growth model incorporates response to changing environmental conditions such as soil moisture, rainfall, temperature, irrigation and solar radiation.  Residue decomposition rate is determined by a process-based decomposition sub model which adjusts for soil and climate conditions of the site.

Hydrology outputs include precipitation, soil evaporation, plant transpiration, runoff, water drainage, irrigation, and soil water balance/hydrologic status that includes average, minimum and maximum over the simulation period.  Irrigation water use is estimated based on crop water use, available water capacity of soil and soil water deficit.  A 100-year statistical analysis that includes average, wet year, dry year and additional statistical graphs and outputs for rainfall, erosion, irrigation, runoff, crop transpiration, soil evaporation, and sediment delivery is generated for use in risk-based conservation planning.

This site provides access to the WEPP model user interface, for appropriate uses by NRCS, partners, and other users. The site includes links for USDA-ARS and USFS.  The USDA-Agricultural Research Service is the lead agency for developing the science in the WEPP model and the model interface.  


WEPP Model User Interface

The WEPP model web interface can be used in Google Chrome or Firefox internet browsers.  A comprehensive user guide is located under the help menu.  Contact your local NRCS State Agronomist or email contacts listed above for username and password if needed. 


For further information, contact: 

Chris Coreil | 817-509-3213 | chris.coreil@usda.gov
National Erosion Specialist
NRCS, Central National Technology Support Center, Fort Worth, Texas

Michael Kucera | 402-437-4133 | michael.kucera@usda.gov
Agronomist/National Erosion Database Steward
NRCS, National Soil Survey Center, Lincoln, Nebraska