Study On Temporal-spatial Variation Of Ice Flood Influence Factors In Inner Mongolia Reach Of The Yellow River

The Yellow River is the most frequently flooded river in China,among which the Ningmeng section is the most serious.Since 1986,the Inner Mongolia section of the Yellow River has had six run-in breaches.In recent years,great changes have taken place in the environment of ice flood disaster in Inner Mongolia section of the Yellow River.Therefore,studying on the change law of the flood environment and its influence on the flood disaster can provide theoretical basis and technical support for the work of the water conservancy.Inner Mongolia section of the Yellow River in this study as the main research object,using a long sequence of hydrologic meteorological data,history data of melting ice flood and remote sensing image,the Inner Mongolia section of the Yellow River to the melting ice flood season temperature,hydraulic conditions,the river boundary to study the change rule of space and time,and on the pregnant disaster environment change on the influence of melting ice flood disasters are analyzed.For the Inner Mongolia section of the Yellow River to provide a basis for disaster prevention and mitigation,emergency rescue work.The main research results are as follows:(1)The temperature in the Inner Mongolia section of the Yellow River is spatially high in the upper reaches and low in the lower reaches.In addition,the temperature in the lower reaches of the Yellow River drops earlier and later in the upper reaches when the river is closed,while the situation is just the opposite when it warms up in the opening period.This special form of river closure provides conditions for the occurrence of flood disaster.According to the mann-Kendall mutation test of the average temperature during the transit flood period in Inner Mongolia section of the Yellow River,the abrupt transition point of the average temperature during the transit flood period in Inner Mongolia section of the Yellow River occurred around 1985,and the average temperature of the transit flood period began to rise significantly after 1985.(2)River in Inner Mongolia section of the Yellow River from 1988 to 2018 in general to the right bank erosion,BaYanGaoLe-the sanhu estuarine river is affected by sandy river,river swing range,the largest lakes estuaries-baotou river due to the(?)urvy,channel change multiterminal,whole presents the tendency of migrating to the left bank,and the oscillating range is mainly concentrated in the curvature of the larger river;In some reaches,the river trend is bent,the deformed river bay is increased,and it is easy to get stuck in the ice dam during the flowing and opening period,causing dangerous situation.From 1981 to 2003,all sections of the Inner Mongolia section of the Yellow River were mainly silted up.From 2003 to 2013,the main channel gradually expanded,and the channel’s flow capacity was improved to some extent.(3)Reservoir after the completion of melting ice flood season under ice flow capacity improved significantly,ling feng flow reduce,then got a great deal of melting ice flood disaster relief,but at the same time also appeared some new problems:the regulation of the reservoir scheduling part makes silting,slot filling incremental increased significantly,and still increasing trend,the melting ice flood disaster prevention and control of disadvantage;In addition,the frequency and proportion of ice jam disasters are significantly higher than before reservoir operation.The research results of this paper can provide some references for the prediction of the future flood situation in the Inner Mongolia section of the Yellow River and the control of the flood disaster in this section at the present stage.