Research On The Influence Of Sand Mining On The Evolution Of The River Channel In The Middle And Lower Reaches Of The Ant River In Harbin

With the acceleration of urbanization,the contradiction between the demand of economic construction for river sediment and the available sediment of river becomes increasingly prominent,which leads to the more serious phenomenon of indiscriminate mining and has a greater negative impact on the river.In order to develop the river sand resources scientifically and reasonably,it is urgent to carry out the research on the influence of sand mining on river channel evolution.This paper takes the middle and lower reaches of the Ant River as the research object,through the means of field investigation,prototype data analysis and mathematical model calculation,based on the Mike numerical simulation software,using the plane two-dimensional flow and sediment mathematical model of the curved river to calculate,comprehensively evaluates the influence of sand mining on the evolution of the main stream of the Ant River,and analyzes the flow movement characteristics and riverbed characteristics of the curved river Deformation law.The main conclusions and results are as follows:(1)Through the mathematical model calculation and analysis before and after sand mining,it can be seen that the influence of sand mining on the water level along the river at all levels of flow is mainly the mining area reach and the upstream reach.After sand mining,the water level in the upstream of the mining area under the condition of the same flow rate all decreases.The water level in the downstream of the mining area is less affected,and the water level is basically the same as before sand mining.(2)The influence of sand mining on the flow velocity is mainly located in the mining area and the surrounding area.The upstream flow velocity of the mining area is limited,and the downstream flow velocity increases little.The main line before and after sand mining has a certain offset except for different flow conditions near the mining area.(3)according to the study of sand mining influence on the typical river sections of the Ant River main stream,it is shown that in the short term,sand mining activities have certain effects on the shoreline,side beach and deep trough near the mining area,but the influence on the river regime is still controllable as a whole.(4)Based on the entropy theory,the analysis of water level change shows that under the same river conditions,the more sand mining per unit length of the river,the greater the entropy of water level change and the more obvious the influence of sand mining.