Research On Flash Flood Warning Technique Coupled With Weather System And Rainfall Forecast

Mountain torrent disaster is one of the common and extremely harmful natural disasters at home and abroad.It is difficult to carry out prevention and control of mountain torrent disaster,and because of its sudden occurrence,great harmfulness and unpredictability.At present,forecast and early warning is the most important non-engineering measure in prevention of mountain torrent disaster.Rainfall information is mainly taken into account in early warning.For small basins with steep flood rise and fall,the use of rainfall for early warning simply cannot meet the requirements of mountain flood disaster prevention in terms of time.Mountain flood early warning research should be conducted with rainfall forecast information and weather system in mind,which is also the research focus of this paper.In this paper,Qingyuan county Hunhe-beikouqian basin and xiuyan county Dayanghe-xiuyan basin in liaoning province as the research background.Firstly,analyze the characteristics of rainstorm and the weather system in the typical basin in liaoning province;Then,analyze the availability of rainfall forecast information;Finally,research mountain flood warning technology combined with the weather system and rainfall forecast information,aiming at prolonging the forecast period and buying precious time for mountain flood disaster prevention.The main research contents and results are as follows:(1)Analysis of Rainstorm Characteristics and Weather System in Typical Watershed of Liaoning Province.Firstly,the weather system that causes rainstorm in liaoning province is expounded,and the situation characteristics of each type of weather system are summarized and sorted out;Then,taking the historical typical flood-causing rainstorm in the study basin as the object,through the summary of the weather system types and rainfall levels that caused the rainstorm,the types of weather systems that mainly affect the study of rainstorm in the basin are obtained,and the rainfall characteristics of common weather systems are summarized.Finally,the typical rainstorm in the basin was taken as an example to analyze the weather system,and the relationship between the weather system situation change process and rainfall was discussed,which laid a preliminary foundation for the subsequent research on mountain flood warning technology.(2)Availability analysis of rainfall forecast information.Firstly,the exploitability evaluation results of existing rainfall forecast information in some basins of liaoning province are summarized and sorted out.After,the exploitability of rainfall forecast information in resarch basin is analyzed and analyzed by using TS scoring,deviation B method and "three rate" method.The conclusion is that the availability of forecast rainfall in small order(no rain,light rain and below)is good.The forecast rainfall value of large scale(heavy rain or above)is relatively small,the accuracy is uncertain and the availability is low;Then the analysis of the typical rainstorm forecast rainfall accuracy is low mainly reflected in the forecast rainfall spatial scale and temporal and spatial distribution;Finally,combined with the analysis of weather system,it further confirms the conclusion of the available analysis of rainfall forecast,and discusses the feasibility of mountain flood warning by coupling weather system and rainfall forecast data,which further lays the foundation of mountain flood warning research.(3)Mountain torrent early warning technology coupled weather system and rainfall forecast.Firstly,the critical rainfall is taken as the warning index,the dynamic critical rainfall curve is obtained by using the Xin 'an river hydrological model,and the critical rainfall at the current moment is found,and the flood early warning is carried out by using the rainfall forecast information.;Then,combined with analysis of weather system,the results of mountain flood warning are qualitatively analyzed and modified to improve the warning effect;Finally,mountain flood warning results of rainfall forecast,probability of rainfall above critical rainfall and weather system analysis are considered as factors for mountain flood warning,research coupling the weather system and rainfall forecast multi-stage flash flood warning technology and analysis of the early warning effect.Finally,the research content of this article has carried on the induction and summary,and tease out the shortcomings in the course of study and work need to be improved.