Estimation of runoff volume and sediment load is the main problem that affects the performance of dams due to the reduction in the storage capacity of their reservoirs and their effect on dam efficiency and operation ...Estimation of runoff volume and sediment load is the main problem that affects the performance of dams due to the reduction in the storage capacity of their reservoirs and their effect on dam efficiency and operation schedule. The simulation models can be considered for this purpose if the continuous field measurements are not available. Soil and Water Assessment Tool (SWAT) and Water Erosion Prediction Project (WEPP) models were applied to estimate the annual runoff volume and sediment load for Duhok Dam Reservoir in north of Duhok/Iraq for the period 1988-2011. The estimated annual runoff volume varied from 2.3 to 34.7 MCM for considered period. Those values were affected by rainfall depth, intensity and runoff coefficient. The resultant annual runoff coefficient for the studied area ranged from 0.05 to 0.35 (average was 0.18) causing an average runoff volume of about 14 MCM. The results of sediment routing indicated that the values of sediment yields varied from 50 to 1400 t/km2/year depending on sub basin properties. The average annual sediment load from the whole watershed is about 120 × 10<sup>3</sup> ton. The estimated total sediment arrived to Duhok Reservoir for the considered period 1988-2011 was about 2.9 × 10<sup>6</sup> ton. The results indicate that both models gave reasonable results in comparison with measured values. Based on statistical criteria, the results of both models are close to gather.展开更多
The influence of ecological technology measures on the annual sediment loads of rivers complies with the principles of statistics. In this paper, the annual sediment load of the Wuding River is taken as the dependent ...The influence of ecological technology measures on the annual sediment loads of rivers complies with the principles of statistics. In this paper, the annual sediment load of the Wuding River is taken as the dependent variable and the rainfall, rainstorms during the flood period of the Wuding River and areas of ecological technology measures are taken as the independent variables to analyze the influence of ecological technology measures on the annual sediment load of the Wuding River during the years 1956 to 2007. This research uses a stepwise regression method. The result shows that 1） the non-linear regression equation composed of three independent variables including 7–8 monthly rainfalls along the Wuding River, areas of ecological technology measures and maximum daily rainfall along the Wuding River has been calculated and set up; the correlation coefficient is R2=0.857 and the significance level is α=0.001. 2） R2=0.717 is adjusted and the regression equation reveals a change of annual sediment load exceeding 71.7% over 52 years; 3） The standardized regression coefficient for ecological technology measure area has the maximum absolute value of the three independent variables shows maximum influence on the change of annual sediment load; and 4） Because of implementing the ecological technology measures, until to year of 2007, when the 7–8 monthly rainfall and maximum daily rainfall are the maximum values in the research section, the annual sediment load is calculated as 149 million ton, which is 36% of the maximum value in the history.展开更多
文摘Estimation of runoff volume and sediment load is the main problem that affects the performance of dams due to the reduction in the storage capacity of their reservoirs and their effect on dam efficiency and operation schedule. The simulation models can be considered for this purpose if the continuous field measurements are not available. Soil and Water Assessment Tool (SWAT) and Water Erosion Prediction Project (WEPP) models were applied to estimate the annual runoff volume and sediment load for Duhok Dam Reservoir in north of Duhok/Iraq for the period 1988-2011. The estimated annual runoff volume varied from 2.3 to 34.7 MCM for considered period. Those values were affected by rainfall depth, intensity and runoff coefficient. The resultant annual runoff coefficient for the studied area ranged from 0.05 to 0.35 (average was 0.18) causing an average runoff volume of about 14 MCM. The results of sediment routing indicated that the values of sediment yields varied from 50 to 1400 t/km2/year depending on sub basin properties. The average annual sediment load from the whole watershed is about 120 × 10<sup>3</sup> ton. The estimated total sediment arrived to Duhok Reservoir for the considered period 1988-2011 was about 2.9 × 10<sup>6</sup> ton. The results indicate that both models gave reasonable results in comparison with measured values. Based on statistical criteria, the results of both models are close to gather.
基金National Key Research and Development Program of China(2016YFC0503700)
文摘The influence of ecological technology measures on the annual sediment loads of rivers complies with the principles of statistics. In this paper, the annual sediment load of the Wuding River is taken as the dependent variable and the rainfall, rainstorms during the flood period of the Wuding River and areas of ecological technology measures are taken as the independent variables to analyze the influence of ecological technology measures on the annual sediment load of the Wuding River during the years 1956 to 2007. This research uses a stepwise regression method. The result shows that 1） the non-linear regression equation composed of three independent variables including 7–8 monthly rainfalls along the Wuding River, areas of ecological technology measures and maximum daily rainfall along the Wuding River has been calculated and set up; the correlation coefficient is R2=0.857 and the significance level is α=0.001. 2） R2=0.717 is adjusted and the regression equation reveals a change of annual sediment load exceeding 71.7% over 52 years; 3） The standardized regression coefficient for ecological technology measure area has the maximum absolute value of the three independent variables shows maximum influence on the change of annual sediment load; and 4） Because of implementing the ecological technology measures, until to year of 2007, when the 7–8 monthly rainfall and maximum daily rainfall are the maximum values in the research section, the annual sediment load is calculated as 149 million ton, which is 36% of the maximum value in the history.
