Water Erosion Prediction Project Enhanced capabilities required WEPP is a joint effort of several federal agencies ARS NRCS FS and their cooperators The USLE equation has been used for the last 30 years by federal and state agencies private industry and individuals to evaluate soil erosion caused by water New environmental concerns New erosion modeling applications Food Security Act of 1985 and Farm bills of 1990 1996 2001 and 2006 In addition to estimating rates of sheet and rill erosion Significant advancement in erosion prediction technology Estimates are needed for erosion by concentrated flow gully Sediment delivery to locations on the landscape Location and amount of deposition along the landscape and in waterways Objective Project will provide agencies with a new generation of process oriented technology for estimating erosion by water Modern erosion theory Experimental research Computer technology Availability of data bases Improved erosion prediction technology is based on Modern hydrologic and erosion science Process oriented Conceptually a significant improvement over USLE 1 WEPP model To run on computers in local offices of the user agencies First tested in 1989 with wider use planned in 1990s However RUSLE and RUSLE 2 have been used for most of the last 15 years RUSLE and RUSLE 2 seem to be incorporating WEPP model parameters Technology is modular so that new research finding can be incorporated without major revisions Validation con t These studies will provide parameter values needed to ensure the WEPP erosion prediction technology will apply across a broad range of climates soils topographies and land uses Validation Research will include laboratory and field studies on more than 75 cropland rangeland and forestland soils and site conditions across the U S This experimental research will be conducted to understand how inherent soil properties and those modified by climate and land use affect infiltration and erodibility Major applications Conservation planning Project planning Inventory and assessment 3 models for field size units 3 models for field size units con t A landscape profile hillslope version that applies to landscape profiles similar to those for the USLE except that the WEPPP model considers depositional areas A small watershed version that uses a representative landscape profile and considers waterways within the application area A grid version that computes sediment movement at all points and in all waterways over a field sized areas 2 WEPP models Describe the influence of climate soil topography over management and supporting practices on erosion deposition sediment yield and sediment characteristics 3
View Full Document
Unlocking...