# WEPP

> Mediated Wiki article. Canonical URL: https://mediated.wiki/source/WEPP
> Markdown URL: https://mediated.wiki/source/WEPP.md
> Source: https://en.wikipedia.org/wiki/WEPP
> Source revision: 1350237595
> License: Creative Commons Attribution-ShareAlike 4.0 International (https://creativecommons.org/licenses/by-sa/4.0/)

The **Water Erosion Prediction Project** (**WEPP**) model is a [physically based](/source/Hydrological_transport_model#Physically_based_models) [erosion](/source/Soil_erosion) simulation model built on the fundamentals of [hydrology](/source/Hydrology), [plant science](/source/Plant_science), [hydraulics](/source/Hydraulics), and [erosion](/source/Soil_erosion) mechanics.[1][2] The model was developed by an interagency team of scientists to replace the [Universal Soil Loss Equation](/source/Universal_Soil_Loss_Equation) (USLE) and has been widely used in the United States and the world.[3] WEPP requires four inputs, i.e., [climate](/source/Climate), [topography](/source/Topography), [soil](/source/Soil), and management ([vegetation](/source/Vegetation)); and provides various types of outputs, including [water balance](/source/Water_balance) ([surface runoff](/source/Surface_runoff), [subsurface flow](/source/Subsurface_flow), and [evapotranspiration](/source/Evapotranspiration)), [soil detachment](/source/Erosion) and [deposition](/source/Deposition_(chemistry)) at points along the slope, [sediment delivery](/source/Sediment_transport), and vegetation growth. The WEPP model has been improved continuously since its public delivery in 1995, and is applicable for a variety of areas (e.g., [cropland](/source/Cropland), [rangeland](/source/Rangeland), [forestry](/source/Forestry), [fisheries](/source/Fisheries), and surface [coal mining](/source/Coal_mining)).

## Capability and strength

WEPP is applicable for a wide range of geographic and [land-use](/source/Land_use) and management conditions, and capable of predicting spatial and temporal distributions of soil detachment and deposition on an event or continuous basis at both small (hillslopes, roads, small parcels) and large ([watershed](/source/Drainage_basin)) scales.[4][5][6] Hillslope applications of the model can simulate a single profile having various distributions of [soil](/source/Soil), [vegetation](/source/Vegetation), and plant/management conditions. In WEPP watershed applications, multiple hillslopes, [channels](/source/Stream_channel), and impoundments can be linked together, and [runoff](/source/Surface_runoff) and [sediment](/source/Sediment) yield from the entire [catchment](/source/Drainage_basin) predicted. The model has been parameterized for a large number of soils across the U.S. and model performance has been assessed under a wide variety of [land-use](/source/Land_use) and management conditions. In addition, WEPP can generate long-term daily climatic data with CLIGEN, an auxiliary [stochastic](/source/Stochastic) climate generator.[7] The CLIGEN database contains weather [statistics](/source/Statistics) from more than 2,600 [weather stations](/source/Weather_station) in the United States. The WEPP climate database is supplemented by the [PRISM database](http://www.prism.oregonstate.edu/),[8] which further refines the climatic data based on [longitude](/source/Longitude), [latitude](/source/Latitude), and [elevation](/source/Elevation). WEPP can provide daily [runoff](/source/Surface_runoff), [subsurface flow](/source/Subsurface_flow), and [sediment](/source/Sediment) output categorized into five [particle-size](/source/Particle_size_(grain_size)) classes: primary [clay](/source/Clay), primary [silt](/source/Silt), small [aggregates](/source/Construction_aggregate), large [aggregates](/source/Construction_aggregate), and primary [sand](/source/Sand), allowing calculation of selective [sediment transport](/source/Sediment_transport), and enrichment of the fine sediment sizes.

## Recent improvement

Since its release in 1995, researchers have made several improvements to the WEPP model. These include improved [algorithms](/source/Algorithm) to simulate the effect of [hydraulic structures](/source/Hydraulic_structure) and impoundments on [runoff](/source/Surface_runoff) and [sediment delivery](/source/Sediment_transport),[9] the addition of [Penman–Monteith ET](/source/Penman%E2%80%93Monteith_equation) algorithms,[10] subsurface converging lateral flow to represent variable source area [runoff](/source/Surface_runoff),[11] improved [canopy](/source/Canopy_(biology)) [biomass](/source/Biomass) [routines](/source/Subroutine) for forested applications,[12] and the incorporation of an alternative, [energy-balance](/source/Groundwater_energy_balance)-based winter hydrologic [routine](/source/Subroutine).[13] A number of modern graphical user interface programs have also been created, to assist in easier application of WEPP. The main interface for the model is a standalone [Windows](/source/Windows) application (downloadable via: [https://www.ars.usda.gov/midwest-area/west-lafayette-in/national-soil-erosion-research/docs/wepp/research/](https://www.ars.usda.gov/midwest-area/west-lafayette-in/national-soil-erosion-research/docs/wepp/research/)), that allows a user to simulate hillslope profiles and small watersheds and have full control over all model inputs (Figure 1). Additionally, [web-based interfaces](http://milford.nserl.purdue.edu) allow rapid use of the model while accessing existing [soil](/source/Soil), [climate](/source/Climate), and management databases (Figure 2).

A number of [geospatial](/source/Geospatial) [interfaces](/source/Interface_(computer_science)) to WEPP (example in Figure 3) are also available:

1. [GeoWEPP](http://geowepp.geog.buffalo.edu/)[14][15][16] – an [ArcView](/source/ArcView) or [ArcGIS](/source/ArcGIS) extension that runs in conjunction with the WEPP Windows interface
1. [On-line web-based GIS interface to WEPP](http://milford.nserl.purdue.edu) using the open source [MapServer](/source/MapServer) [GIS](/source/Geographic_information_system) program[17]
1. [Iowa Daily Erosion Project](http://wepp.mesonet.agron.iastate.edu)[18]
1. [NetMap](http://www.netmaptools.org/)[19]

## Forest and rangeland applications

The [U.S. Forest Service](/source/United_States_Forest_Service) has developed a suite of internet [interfaces](/source/Interface_(computer_science)), the [Forest Service WEPP (FS WEPP) interfaces](http://forest.moscowfsl.wsu.edu/fswepp/), for easier applications by [stakeholders](/source/Stakeholder_(corporate)) in forest and [rangeland management](/source/Rangeland_management) (forest engineers, rangeland scientists, federal and state regulatory personnel) and the general public.[20] The interfaces can be readily accessed and run through the internet ([http://forest.moscowfsl.wsu.edu/fswepp/](http://forest.moscowfsl.wsu.edu/fswepp/)), and do not require any in-depth understanding of the [hydrology](/source/Hydrology), [hydraulic](/source/Hydraulics) and [erosion](/source/Erosion) [principles](/source/Principle) embedded in the WEPP model. The FS WEPP interfaces include:

- Cross Drain – to predict sediment yield from a road segment across a [buffer](/source/Riparian_zone)
- Rock:Clime – to create and download a modified WEPP climate file
- WEPP:Road – to predict erosion from a forest road segment
- WEPP:Road Batch – to predict erosion from multiple forest road segments
- Disturbed WEPP – to predict erosion from rangeland and forest disturbances ([wildfire](/source/Wildfire), [harvest operations](/source/Logging))
- Tahoe Basin Sediment Model (under construction) – to predict runoff and erosion for the [Lake Tahoe](/source/Lake_Tahoe) Basin
- WEPP FuME (Fuel Management) – to predict erosion from fuel management practices
- ERMiT (Erosion Risk Management Tool) – to predict the [probability](/source/Probability) of [sediment delivery](/source/Sediment_transport) with various mitigation treatments in each of five years following [wildfire](/source/Wildfire)

## See also

- [Erosion](/source/Erosion)
- [Erosion prediction](/source/Erosion_prediction)
- [Erosion control](/source/Erosion_control)
- [Sediment control](/source/Sediment_control)
- [Hydrology (agriculture)](/source/Hydrology_(agriculture))
- [Hydrological modelling](/source/Hydrological_modelling)
- [Hydrological transport model](/source/Hydrological_transport_model)
- [Runoff model (reservoir)](/source/Runoff_model_(reservoir))

## References

1. Laflen, J.M., L.J. Lane, and G.R. Foster. 1991. WEPP—a next generation of erosion prediction technology. *Journal of Soil Water Conservation* 46(1): 34–38.

1. Laflen, J.M., W.J. Elliot, D.C. Flanagan, C.R. Meyer, and M.A. Nearing. 1997. WEPP predicting water erosion using a process-based model. *Journal of Soil Water Conservation* 52(2): 96–102.

1. Flanagan, D.C., J.E. Gilley and T.G. Franti. 2007. Water Erosion Prediction Project (WEPP): development history, model capabilities, and future enhancements. *Transactions of the ASABE* 50(5):1603-1612.

1. Flanagan, D.C., and M.A. Nearing (eds.). 1995. *USDA-Water Erosion Prediction Project (WEPP) Hillslope Profile and Watershed Model Documentation*. NSERL Report No. 10, National Soil Erosion Research Laboratory, USDA-Agricultural Research Service, West Lafayette, Indiana.

1. Flanagan, D.C., and S.J. Livingston, (eds.) 1995. *WEPP User Summary*. NSERL Rep. No. 11. West Lafayette, IN: USDA ARS NSERL.

1. Flanagan, D.C., J.C. Ascough II, M.A. Nearing and J.M. Laflen. 2001. Chapter 7: The Water Erosion Prediction Project (WEPP) Model. In (R.S. Harmon and W.W. Doe III, eds.): *Landscape Erosion and Evolution Modeling*. Kluwer Academic / Plenum Publishers, New York, NY. 145-199

1. Nicks, A.D., L.J. Lane, and G.A. Gander. 1995. Weather generator. In: Flanagan, D.C. and M.A. Nearing (eds.), *USDA-Water Erosion Prediction Project Hillslope Profile and Watershed Model Documentation*. NSERL Rep. 10. West Lafayette, IN: USDA ARS NSERL.

1. Daly, C. 2009. PRISM Group. Available at: [http://www.prism.oregonstate.edu/](http://www.prism.oregonstate.edu/).

1. Wu, J.Q., and S. Dun. 1998. Upgrading the WEPP watershed version for forest conditions. Final Report to USDA Forest Service, Rocky Mountain Research Station, Moscow, ID.

1. Wu, J.Q., S. Dun, W.J. Elliot, and D.C. Flanagan. 2004. Modification and testing of the evapotranspiration (ET) routines in the WEPP model. Presented at *the 2004 ASAE Annual International Meeting*, August 1−4, 2004, Ottawa, Canada. St. Joseph, MI: ASAE.

1. Wu, J.Q., S. Dun, W.J. Elliot, and D.C. Flanagan. 2004. Subsurface water flow routines in the WEPP model: Modification and validation. Presented at *the 2004 ASAE Annual International Meeting*, August 1−4, 2004, Ottawa, Canada. St. Joseph, MI: ASAE.

1. Dun, S., J.Q. Wu, W.J. Elliot, P.R. Robichaud, D.C. Flanagan, J.R. Frankenberger, R.E. Brown and A.D. Xu. 2009. Adapting the Water Erosion Prediction Project (WEPP) Model for forest applications. *Journal of Hydrology* 366(1−4): 45–54.

1. Singh, P., J.Q. Wu, D.K. McCool, S. Dun, C-H. Lin, and J.R. Morse. 2009. Winter hydrologic and erosion processes in the U.S. Palouse region: field experimentation and WEPP simulation. *Vadose Zone Journal* 8(2): 426–436.

1. Cochrane, T.A., and D.C. Flanagan. 1999. Assessing water erosion in small watersheds using WEPP with GIS and digital elevation models. *Journal of Soil Water Conservation* 54(4): 678–685.

1. Renschler, C.S., D.C. Flanagan, B.A. Engel and J.R. Frankenberger. 2002. GeoWEPP – the geospatial interface to the Water Erosion Prediction Project. ASAE Paper No. 02-2171. 10 pp.

1. Renschler, C.S. 2003. Designing geo-spatial interfaces to scale process models: the GeoWEPP approach. *Hydrological Processes* 17(5): 1005–1017.

1. Flanagan, D. C., J. R. Frankenberger and B. A. Engel. 2004. Web-based GIS application of the WEPP model. Paper No. 042024. Presented at *the 2004 ASAE Annual International Meeting*, August 1−4, 2004, Ottawa, Canada. St. Joseph, MI: ASAE. 12 p.

1. Cruse, R.M., D.C. Flanagan, J.R. Frankenberger, B.K. Gelder, D. Herzmann, D. James, W. Krajewski, M. Kraszewski, J.M. Laflen, and D. Todey. 2006. Daily estimates of rainfall, water runoff, and soil erosion in Iowa. *Journal of Soil Water Conservation*. 61(4): 191–199.

1. Benda, L., D. Miller, K. Andras, P. Bigelow, G. Reeves, and D. Michael. 2007. NetMap: a new tool in support of watershed science and resource management. *Forest Science* 53(2): 206–219.

1. Elliot, W.J. 2004. WEPP internet interfaces for forest erosion prediction. *Journal of the American Water Resources Association* 40(2): 299–309.

## External links

- [WEPP – Official site](https://www.ars.usda.gov/midwest-area/west-lafayette-in/national-soil-erosion-research/docs/wepp/research/) – [National Soil Erosion Research Laboratory (NSERL), USDA Agricultural Research Service](https://www.ars.usda.gov/midwest-area/west-lafayette-in/national-soil-erosion-research/)
- [WEPP Web Interfaces](http://milford.nserl.purdue.edu/wepp/weppV1.html) – [NSERL, USDA Agricultural Research Service](https://www.ars.usda.gov/midwest-area/west-lafayette-in/national-soil-erosion-research/)
- [Forest Service WEPP Interfaces](http://forest.moscowfsl.wsu.edu/fswepp/) – [USDA Forest Service](/source/USDA_Forest_Service) [Rocky Mountain Research Station](/source/Rocky_Mountain_Research_Station)
- [GeoWEPP](http://geowepp.geog.buffalo.edu/) – [SUNY Buffalo](/source/University_at_Buffalo,_The_State_University_of_New_York)
- [NetMap](http://www.netmaptools.org/) – Earth Systems Institute

---
Adapted from the Wikipedia article [WEPP](https://en.wikipedia.org/wiki/WEPP) by Wikipedia contributors ([contributor history](https://en.wikipedia.org/wiki/WEPP?action=history)). Available under [Creative Commons Attribution-ShareAlike 4.0 International](https://creativecommons.org/licenses/by-sa/4.0/). Changes may have been made.