Simulations of hillslope soil erosion patterns with the WEPP model in Tanzania

O. Vigiak, S. Chitrakar, G. Sterk, D. Flanagan

Research output: Contribution to conferencePosterProfessional

Abstract

The Water Erosion Prediction Project (WEPP) model simulates erosion processes along hillslope profiles. In this study, WEPP performance in depicting patterns of erosion and deposition along a slope was tested. Event based simulations were compared to observations of soil erosion along two longitudinal transects in the Tanzanian Highlands. Transects were comprised of different annual and perennial tropical crops, but had only a single soil type. Measurements of runoff and soil loss in Gerlach troughs at different transect positions allowed calibration of three important WEPP soil parameters: effective hydraulic conductivity, soil moisture and interrill erodibility. Model calibration on 4 events yielded a root mean square error (RMSE) of soil loss predictions of 1.14. Model validation on 5 other events yielded a RMSE of 0.15, confirming the simulation goodness-of-fit. Finally, model simulations of erosion and deposition along the hillslope were compared to the soil erosion pattern observed by qualitative surveys. WEPP simulations showed generally good agreement with the observations, but had less agreement in the lower transect sections, where soil loss was overpredicted. This was acceptable when considering that transect lengths (above 200 m) were greater than the WEPP recommended limits. In conclusion, the WEPP model performed well in the Tanzanian Highland environment
Original languageEnglish
Publication statusPublished - 2004
EventThe 68th ASA-CSSA-SSSA with Canadian Society of Soil Science Annual meeting "Science to Secure Food & The Environment" -
Duration: 31 Oct 20044 Nov 2004

Conference

ConferenceThe 68th ASA-CSSA-SSSA with Canadian Society of Soil Science Annual meeting "Science to Secure Food & The Environment"
Period31/10/044/11/04

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