Research On Flood Forecasting And Warning Method Under Uncertain Information Conditions

Among the natural disasters in China,the flood disaster is one of the most serious disasters,which seriously threatens the safety of people's lives and property.Especially in the mountainous small watershed area,its water storage capacity is weak,and the suddenness of flash floods is also strong.Therefore,the prevention of flash flood disasters and the study of flash flood forecasting and early warning are the key issues in the field of hydrology and water resources.However,the issue of mountain flood early warning decision-making involves uncertain factors such as rainfall information,wading engineering and the impact of the underlying surface,and the coexistence of multiple early warning modes.During the early warning process,many kinds of uncertain information often interfere with each other,making it difficult to proceed Early warning decision-making for torrents.In order to solve the uncertainty of flash flood warning,this paper combines the actual situation of flash flood warning in small river basins.The main research problems and results are as follows:(1)Multi-scale and multi-method mountain flood disaster early warning model.Combined with the various flash flood warning models commonly used in actual flash flood warning work,different flash flood warning methods,early warning time scales,early warning levels,etc.were analyzed and compared,and indicators such as watershed information,vegetation coverage,terrain index,human activity,etc.were selected to establish multi-scale Multi-method mountain flood disaster early warning model selection model.Taking five typical watersheds in Huanren County,Liaoning Province as the research object,a case study is conducted on the selection of early warning models for mountain flood disasters in small watersheds;based on the results of model comparison and selection,the early warning models for mountain floods in five small watersheds are optimized,and the calculation schemes Rainfall early warning indicators and flow early warning indicators.(2)Research on forecast of flood peak discharge in small watersheds with uncertain rainfall.Flood peak forecasting in small watersheds is an important means of mountain flood disaster prevention,but its flood peak flow is not easy to predict accurately.In order to better predict the peak discharge in the small watershed area,combined with the uncertain information such as rainfall level,time distribution and spatial distribution,refer to the inference formula method and empirical formula method in the design flood calculation of the small watershed,and consider the peak rainfall Factors such as the type and the early influence of rainfall,etc.,proposed a peak forecasting model that can be applied to small watershed areas;and taking the Sidaohezi watershed in Liaoning Province as an example to study the application of the flood peak forecasting model.(3)Research on risk classification of mountain flood disaster areas affected by wading projects and underlying surfaces.Watershed wading projects and underlying surface changes have a great impact on the effectiveness of early warning of mountain flood disasters.In order to explore the impact of these changes,a comparative analysis of the flood evolution process and inundation indicators under different design conditions is carried out.Taking the small watershed of Huanren County in Liaoning Province as the research object,combined with geographic data and geological disaster survey results,we selected geological disasters,rainstorms,wading projects,vegetation coverage and other risk source indicators to establish a complete set of mountain flood disaster regional risk levels The evaluation system has laid the foundation for the research on the early warning method of torrents under comprehensive uncertain information.(4)Research on early warning methods of torrents under comprehensive uncertain information.Combining the uncertain information of rainfall,the uncertainty of the impact of wading engineering and underlying surface changes,combined with the multi-scale and multi-method research results of mountain flood disaster early warning model,through the selection of early warning index model,rainfall uncertainty and analysis of mountain flood disaster risk Taking the Sidaohezi Basin as an example,the study of early warning of mountain torrents was conducted.By comparing the effects of mountain flood warnings under a combination of multiple uncertain information,it can be seen that when comprehensive uncertain information is considered,the accuracy of flood peak forecasting can be improved to ensure the accuracy of mountain flood warnings.Finally,summarizing the contents of the full text and looking forward to the future areas related to early warning of mountain flood disasters that need to be resolved and improved.