Improving and calibrating channel erosion simulation in the Water Erosion Prediction Project (WEPP) model

JOURNAL OF ENVIRONMENTAL MANAGEMENT

卷:291

Article

Guo, Tian¹  Srivastava, Anurag²  Flanagan, Dennis C.^1,3 

[1] Purdue Univ, Agr & Biol Engn Dept, W Lafayette, IN 47907 USA

[2] Univ Idaho, Soil & Water Syst Dept, Moscow, ID 83843 USA

[3] ARS, USDA, Natl Soil Eros Res Lab, W Lafayette, IN USA

关键词: Soil detachment;    Channel erosion;    Erosion modeling;    Model improvements;    Agriculture;    Watershed hydrology;   

DOI  :  10.1016/j.jenvman.2021.112616

来源: Elsevier

【 摘 要 】

The Water Erosion Prediction Project (WEPP) model has been widely used to assess the impacts of management practices and climate change on runoff and soil loss at both hillslope and watershed scales. However, the representation of channel erosion processes in WEPP has not been changed significantly since it was released. The current (WEPP v2012.8) and previous WEPP versions assume that channel input erodibility parameters are constant through time, which may lead to erroneous channel detachment predictions, especially for cropland with substantial tillage operations. In this research, the temporally constant values of channel erodibility and critical shear stress were replaced by daily updated values, using the same temporal erodibility and critical shear stress adjustments that are applied in hillslope profile simulations for rill detachment. Observed watershed-scale runoff and soil erosion data from six agricultural watersheds were used to calibrate and compare the WEPP model performance in simulating channel runoff volumes and soil losses before and after the modification. The research showed both WEPP v2012.8 and the modified WEPP model (WEPP_CE) could satisfactorily simulate event-based hydrology and soil erosion at the watershed outlets after calibration. The WEPP_CE model with temporally varying channel erodibility and critical shear stress values demonstrated improved representation of the physical processes in channel soil detachment. Continued improvement in the representation of channel erosion processes in WEPP and other process-based models is needed. The improved WEPP model can be used to evaluate the effectiveness of soil conservation practices on hydrology and erosion in further research.

【 授权许可】

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