This paper presents an analysis of the changes of the longitudinal and lateral profiles in the meander- ing reach of the Lower Wei River over the period from October 1973 to October 1976 during the course of degradati...This paper presents an analysis of the changes of the longitudinal and lateral profiles in the meander- ing reach of the Lower Wei River over the period from October 1973 to October 1976 during the course of degradation.Analysis results indicated that retrogressive erosion and subsequent downstream erosion occurred in the reach due to the lowering in the Tongguan elevation and the inflowing water carrying low sediment con- centrations.At the end of the degradation,the main channel widths of the majority ...展开更多
Jing River is a tributary of the Wei River which is the largest tributary of the Yellow River. Sediments eroded from the upland of the Jing River basin are one of the major contributors of sediment entering the lower ...Jing River is a tributary of the Wei River which is the largest tributary of the Yellow River. Sediments eroded from the upland of the Jing River basin are one of the major contributors of sediment entering the lower Wei River(LWR). The Dongzhuang reservoir is designed to be constructed on the lower Jing River for flood control and water resources regulation, and this may change the sustainable management of the LWR as changed channel deposition by trapping sediments and releasing concentration-limited flow. Its effects on the LWR, especially the deposition distribution, should be analyzed. The steady quasi-two-dimensional dynamic model was adopted to estimate the deposition processes in the LWR. Then, the qualitative effects of the Dongzhuang reservoir on channel deposition were evaluated and compared with historical data, including capacity loss in other reservoirs and measured deposition in the LWR. Analyses indicated that the annual deposition in the LWR will decrease by approximately two-thirds due to the reservoir’s operation. After 15 years of operation, the effects of the Dongzhuang reservoir on the lower channel will decrease gradually. Moreover, its effects on lateral distribution in different sub-reaches are different. After the reservoir’s operation, the floodplain of the Xianyang–Lintong(XY-LT) sub-reach will change its sediment regime from deposition to erosion. For the Lintong–Huaxian(LT-HX) sub-reach, deposition in the main channel will be more serious during the first 30 years of operation. For the Huaxian–Tongguan (HX-TG) sub-reach, the reservoir will have almost no effects on the lateral distribution. All these analyses may benefit the sustainable management of the Wei River and the Yellow River.展开更多
This paper presents a study of the variation of the elevation of Tongguan, which is located in the backwater zone of the Sanmenxia Reservoir, in response to changes in flow runoff. The analysis indicated that the rise...This paper presents a study of the variation of the elevation of Tongguan, which is located in the backwater zone of the Sanmenxia Reservoir, in response to changes in flow runoff. The analysis indicated that the rise of the eleva- tion of Tongguan, which is defined as the stage corresponding to a discharge of 1000 m3/s at Tongguan station, is controlled by the stream energy. A close relationship existed between the elevation of Tongguan and the superimposed stream en- ergy that integrates the current and the preceding years’ flow and dam operation conditions. When the flow runoff remains relatively constant and the pool level of the dam has a rela- tively large range of variations, then the elevation of Tong- guan is primarily controlled by the dam operation conditions. On the other hand, if the flow runoff has a relatively large range of variations and the pool level of the dam remains relatively constant, then the elevation of Tongguan is primar- ily controlled by the flow conditions. These findings are of importance for optimizing the dam operation in order to lower and control the elevation of Tongguan, and therefore to minimize the backwater effect of the dam operation.展开更多
基金Supported by the Natural Science Foundation of China (50409002)by the Science Fund for Creative Research Groups of the Natural Science Foundation of China (50221903).
文摘This paper presents an analysis of the changes of the longitudinal and lateral profiles in the meander- ing reach of the Lower Wei River over the period from October 1973 to October 1976 during the course of degradation.Analysis results indicated that retrogressive erosion and subsequent downstream erosion occurred in the reach due to the lowering in the Tongguan elevation and the inflowing water carrying low sediment con- centrations.At the end of the degradation,the main channel widths of the majority ...
基金The research reported in this manuscript is funded by the National Natural Science Foundation of China(Grants No.51979264 and 51479179)。
文摘Jing River is a tributary of the Wei River which is the largest tributary of the Yellow River. Sediments eroded from the upland of the Jing River basin are one of the major contributors of sediment entering the lower Wei River(LWR). The Dongzhuang reservoir is designed to be constructed on the lower Jing River for flood control and water resources regulation, and this may change the sustainable management of the LWR as changed channel deposition by trapping sediments and releasing concentration-limited flow. Its effects on the LWR, especially the deposition distribution, should be analyzed. The steady quasi-two-dimensional dynamic model was adopted to estimate the deposition processes in the LWR. Then, the qualitative effects of the Dongzhuang reservoir on channel deposition were evaluated and compared with historical data, including capacity loss in other reservoirs and measured deposition in the LWR. Analyses indicated that the annual deposition in the LWR will decrease by approximately two-thirds due to the reservoir’s operation. After 15 years of operation, the effects of the Dongzhuang reservoir on the lower channel will decrease gradually. Moreover, its effects on lateral distribution in different sub-reaches are different. After the reservoir’s operation, the floodplain of the Xianyang–Lintong(XY-LT) sub-reach will change its sediment regime from deposition to erosion. For the Lintong–Huaxian(LT-HX) sub-reach, deposition in the main channel will be more serious during the first 30 years of operation. For the Huaxian–Tongguan (HX-TG) sub-reach, the reservoir will have almost no effects on the lateral distribution. All these analyses may benefit the sustainable management of the Wei River and the Yellow River.
文摘This paper presents a study of the variation of the elevation of Tongguan, which is located in the backwater zone of the Sanmenxia Reservoir, in response to changes in flow runoff. The analysis indicated that the rise of the eleva- tion of Tongguan, which is defined as the stage corresponding to a discharge of 1000 m3/s at Tongguan station, is controlled by the stream energy. A close relationship existed between the elevation of Tongguan and the superimposed stream en- ergy that integrates the current and the preceding years’ flow and dam operation conditions. When the flow runoff remains relatively constant and the pool level of the dam has a rela- tively large range of variations, then the elevation of Tong- guan is primarily controlled by the dam operation conditions. On the other hand, if the flow runoff has a relatively large range of variations and the pool level of the dam remains relatively constant, then the elevation of Tongguan is primar- ily controlled by the flow conditions. These findings are of importance for optimizing the dam operation in order to lower and control the elevation of Tongguan, and therefore to minimize the backwater effect of the dam operation.
