Evolution And Simulation Of Multi-stage Bifurcation Channel In Ganjiang River

The rapid development of social economy has greatly promoted the construction of flood control,irrigation,water supply,power generation,soil and water conservation and other engineering facilities in Ganjiang River Basin.Under the dual effects of natural changes and human activities,the hydrological situation of the Ganjiang Weilu River Basin has changed greatly,and the trend of river course evolution has become more complex.It is of great significance to study the evolution and Simulation of the Ganjiang River's tail channel with multi-level branching for maintaining the healthy development of the tail channel.In this paper,the characteristics of water and sediment,the evolution of river course and the meshing of Ganjiang river sink are studied and analyzed by using the method of combined analysis of measured data and mathematical model.Based on the measured water and sediment data,using Mann-Kendall trend test method and plotting the water level-discharge diagram of typical years,the variation trend of water level and discharge at Waizhou Station during 1956-2013 is analyzed.By further analyzing the relationship between the water level difference of each branch-Waizhou Station and the inflow from the continent,the characteristic outflow of the West Branch and the middle branch is obtained.Based on the evolution law of the river course and the situation of water and sediment inflow,it is concluded that in recent years,the Tailu River has been scoured,cut down,floodplain eroded,and coastline moved back.Finally,the computational area is meshed based on the method of boundary stitching and expanding,and a two-dimensional mathematical model of water and sediment is established,which is calibrated and verified by the measured data.Based on the established two-dimensional water and sediment mathematical model of Ganjiang River,the influence of Yangzizhou control project on water level,flow field and channel scouring and silting is analyzed,which provides technical support for the simulation of other regulation projects.