Physical Model Results on Intrusion Between Channel and Tributary in Xiaolangdi Reservoir

Abstract

Interaction between reservoir sedimentation topography and water and sediment transportation characteristic is deeply affected the reservoir storage capacity. From the surveyed data of reservoir built many years ago, it shows that when there is a bar in tributary mouth, the tributary volume below the bar will become nullification during the period of flood control or water and sediment regulation of reservoir. There are more tributaries in Xiaolangdi reservoir than the others that it occupies 41.3% of the total initial volume of tributary volume. Obviously, the effective use of tributary volume has been important influenced by comprehensive utilization efficiency of reservoir scheduling, such as flood control, sedimentation reduction and comprehensive utilization. Results of Xiaolangdi Reservoir mobile-bed physical model experiments show that tributary is equivalent to lateral extension of river bed, the tributary intrusion deposition process have strongly relations with the factors, such as original topography, river bed deposition shape and its regime, process with input discharge and input sediment, and method of reservoir regulation. The variation trends of main river and tributary terrain forecasted by model test are basically in accordance with field surveyed data. Based on the physical graphics revealed by mobile-bed physical model experiments, a method of tributary diversion ratio is preliminarily generalized for calculation and is verified by field surveyed data. The results could be used for research, design, and forecasting of reservoirs in sediment-laden river.