Modeling of Sediment Yield From Anjeni‐Gauged Watershed, Ethiopia Using SWAT Model¹

Abstract

Setegn, Shimelis G., Bijan Dargahi, Ragahavan Srinivasan, and Assefa M. Melesse, 2010. Modeling of Sediment Yield From Anjeni‐Gauged Watershed, Ethiopia Using SWAT Model. Journal of the American Water Resources Association (JAWRA) 46(3):514‐526. DOI: 10.1111/j.1752‐1688.2010.00431.x Abstract: The Soil and Water Assessment Tool (SWAT) was tested for prediction of sediment yield in Anjeni‐gauged watershed, Ethiopia. Soil erosion and land degradation is a major problem on the Ethiopian highlands. The objectives of this study were to evaluate the performance and applicability of SWAT model in predicting monthly sediment yield and assess the impacts of subbasin delineation and slope discretization on the prediction of sediment yield. Ten years monthly meteorological, flow and sediment data were used for model calibration and validation. The annual average measured sediment yield was 24.6 tonnes/ha. The annual average simulated sediment yield was 27.8 and 29.5 tones/ha for calibration and validation periods, respectively. The study found that the observed values showed good agreement with the simulated sediment yield with Nash‐Sutcliffe efficiency (NSE) = 0.81, percent bias (PBIAS) = 28%, RMSE‐observations standard deviation ratio (RSR) = 0.23, and coefficient of determination (R²) = 0.86 for calibration and NSE = 0.79, PBIAS = 30%, RSR = 0.29, and R² = 0.84 for validation periods. The model can be used for further analysis of different management scenarios that could help different stakeholders to plan and implement appropriate soil and water conservation strategies.

Sustaining reservoir use through sediment trapping in NW Ethiopia

“…This result agrees with the findings of previous studies in northwest Ethiopian highlands. For example, ~25 t ha -1 y -1 (Setegn et al, 2010;Yeshaneh et al, 2014) and 8.6-55 t ha -1 y -1 (Mekonnen et al, 2015b). The result was also within the range of 3-49 t ha -1 y -1 found by Tamene et al (2006a) ) is the contribution of Minizr catchment.…”

“…For example, in northwest Ethiopia, average annual sediment yield of 24.6 t ha -1 at Anjeni catchment (Setegn et al, 2010) and 13.6 t ha -1 at Angereb catchment (Amare, 2005) were reported. In the northern part of Ethiopia, the annual sediment yield of 10 catchments was estimated at 4-18 t ha -1 (Haregeweyn et al, 2008) and 3.4-49 t ha -1 (Tamene et al, 2006a) for another 11 catchments in the same region.…”

“…Some examples of models that have been used to predict catchment sediment yield are: Water Erosion Prediction Project (Zeleke, 2000) and Soil and Water analysis Tool (Setegn et al, 2010) at Anjeni catchment, northwest Ethiopia, and the Agricultural Non-Point Source Pollution model (Haregeweyn & Yohannes, 2003) at Augucho catchment, eastern Ethiopia. However, such models require large input datasets and if such models are applied in conditions where the necessary data are not available and, therefore, a proper calibration cannot be performed, the results may become unreliable Haregeweyn et al, 2013).…”

Model parameter transfer for streamflow and sediment loss prediction with SWAT in a tropical watershed

“…We compared the modeled sediment yield results for Minchet catchment to WLRC compiled sediment yield results and to other studies (Bosshardt, 1997;Setegn et al, 2010;Guzman et al, 2013;Lemann et al, 2016), which show reported mean annual sediment yields from 19.3 ha −1 y −1 to 29.5 ha −1 y −1 and resulting in an overall mean annual sediment yield of 26.12 ha −1 y −1 for the period of 1984 to 1993. The long term mean annual measured sediment yield from the WLRC grab samples for our study from 1984 to 2014 are 20.65 ha −1 y −1 while the SWAT modeled annual mean was 18.8 ha −1 y −1 (-8.95%).…”

“…There have been numerous studies conducted in the Ethiopian highlands on modelling discharge and soil erosion with SWAT (Ndomba et al, 2008;Mekonnen et al, 2009;Setegn et al, 2010;Easton et al, 2010;Betrie et al, 2011;Notter et al, 2012;Yesuf et al, 2016;Lemann et al, 2016) to cite an incomplete list only. All of them focused on modeleling with limited measured data and none did attempt the model parameter transfer for lack of appropriate opportunities.…”