The Difference Analysis Of Lag Response Of Alluvial River

The lagging response of the alluvial rivers is disturbed by the perturbation itself,which is widely confirmed in the evolution of alluvial rivers.The time scale of the lagging response of different characteristics is obviously different In this paper,the typical river alluvial river in China is taken as the research object,and the difference between the adjustment time of the channel shape lag response and its influencing factors after the alluvial river is disturbed by the combination of theoretical research and prototype data.The research results are of great academic significance to further improve the lag response theory of river bed evolution.We chose Yellow River in Inner Mongolia,the downstream reaches of the Yellow River,Weihe River downstream of the river,as well as the middle reaches of the Yangtze River,the Yangtze River downstream river,downstream Hanjiang river,etc.,a collection of selected major hydrological stations in recent decades river water and sediment and river section morphology data.The changes of water and sediment conditions in the upper reaches of the selected main water conservancy project are taken as the demarcation point,and the changes of water and sediment interannual and annual changes are analyzed.At the same time,the adjustment law of the section shape of the river section was analyzed with the characteristics of flat beach flow(sandy river)and dry area(Shahe River).On the basis of summarizing the previous research results,the paper studies the lag response of the tunnels in the lower reaches of the Yangtze River and the Huangzhuang station in the lower reaches of the Hanjiang River,and establishes the lag response model for the two sections.Using the wavelet analysis on the reach of identifying multi-time scale,establishing the primary and secondary time period within the range,when the segment length,to establish a non-uniform time lag response model is determined by the superposition of the primary and secondary rocking curve period.Model applied to the Datong station and Huangzhuang station has achieved good results.The lagging response time of Datong station,Huangzhuang station was analyzed by using the moving average method.Based on the previous research results,the adjustment time of the lagging response of the 13 hydrological stations was summarized,And its associated water and sediment characteristic variables.Based on the effect of water and sediment on the river bed adjustment,considering the influence factors such as sediment load,sediment concentration,flow rate,sediment coefficient,bed size and so on,the relationship between the lag response time and the main influencing factors T=K(S/d50)m,which is substituted into the study section...