Research On The Influence Of Sand Mining In Oroqen Autonomous Banner On River Stability And Flood Control Safety

River sand is widely used in the construction of bridges,roads,urban construction and so on.At present,the phenomenon of river sand mining is widespread,and the behavior of sand mining will have a certain impact,especially on the river,and the impact on river stability and flood control safety is inevitable.Although sand mining on the river can reduce the river bed elevation to a certain extent,broaden the effective flow area of the river,which is conducive to flood discharge,sand mining will lead to the reduction of river sand and the reduction of water storage capacity of the river bed,which makes the bank scouring and river diversion occur from time to time.Once the river diversion occurs,the villages on both sides of the river will become unsafe and the crops will be affected.This study is based on the data of river sand mining in Oroqen Autonomous Banner to study the influence of river sand mining on river regime stability and flood control safety.Firstly,according to the measured hydrological data,the horizontal and vertical stability indexes of the reach where all sand mining areas are located are calculated.Based on these indexes,it is concluded whether sand mining is suitable in this area and whether sand mining will have a greater adverse impact on the reach.Then,according to the basic data of the study area,using Mike software,combined with the location distribution of sand mining area in Oroqen Autonomous Banner,two-dimensional flow mathematical models were established in Gan and Nuomin reach respectively,and Mike21 flow model module was selected to verify the feasibility of the model.Combined with the sand mining planning of the river reach where the mining area is located and the scope of the mining area,the model is used to analyze and calculate the changes of river water level under different flow rates before and after sand mining,so as to study the impact of river sand mining on flood control safety.The results show that the lateral stability of sand mining channel is worse than the longitudinal stability.In order to prevent slope instability caused by sand mining,the slope should be treated in time after sand mining;The trend of river water level after sand mining is consistent with that before sand mining.In the upstream of sand mining area,the water level after sand mining decreases slightly;In the downstream of the sand mining area,the water level after sand mining rises slightly;Under different flow rates,the greater the flow rate is,the greater the change range of water level before and after sand mining is,that is,the greater the impact on water level is;Reasonable and appropriate sand mining can expand the river flow area,and combined with the slope care after sand mining,it is conducive to river flood discharge.