Study on the Influence of Large-Scale Reservoir Operation on Channel Avulsion of the Tail Reach of Estuaries
In order to quantitatively study the effects of the Xiaolangdi Reservoir on the channel avulsion of the tail reach of the Yellow River estuary,a method for determining the avulsion threshold was proposed based on the improved entropy weight method.According to the meas-ured flow-sediment data,the avulsion threshold index calculation equation and the corresponding channel avulsion threshold in the tail reach of the Yellow River estuary were determined,on the basis of restoring the adjustment process of flow and sediment and the channel morpholo-gy when there was no Xiaolangdi Reservoir,and combined with the avulsion threshold,the difference in the probability of the channel avul-sion in the tail reach of the Yellow River estuary with and without the Xiaolangdi Reservoir was compared and analyzed.The results show that the river facies coefficient and fluvial erosion intensity are the two dominant indicators in the boundary and flow-sediment conditions respec-tively.Based on the measured data,the avulsion threshold index calculation equation established by these two dominant indicators,and the avulsion threshold of the tail reach of the Yellow River estuary is obtained as 38.16,that is,when the avulsion threshold index is greater than 38.16,the channel avulsion occurs in the tail reach.The application of the Xiaolangdi Reservoir restricts the amount of sediment entering into the tail reach of the Yellow River estuary,and the probability of the channel avulsion is significantly reduced.
channel avulsion thresholdflow and sediment regimechannel adjustmentstail channel of the Yellow River estuaryXiaolangdi Reservoir
国家科技期刊平台
NSTL
万方数据
