Study On Risk Analysis And Early Warning Index Extraction Method Of Flood Disaster In Plain Lake Area

Flood disasters seriously threaten the regional social economy and the safety of people’s lives and properties.The plains and lakes of our country have flat terrain,dense water networks and large populations,and there is always a greater risk of flood disasters.Analyzing the flood disaster risk in plain lake areas,extracting early warning indicators,and establishing an early warning mechanism to reduce flood disaster losses are urgent tasks.This paper combines flood disaster investigation and evaluation,digital elevation model data,historical flood disaster data,etc.to study flood disasters in plain lake areas,and carries out risk analysis and early warning index extraction research work for flood disasters in plain lake areas,and further improves the comprehensive defense capabilities of flood disasters in plain lake areas,to promote the continuous development of the rural grassroots flood control management system and management capabilities in the direction of modernization.The main contents and achievements of this paper are as follows:(1)Based on the distributed drainage area,the flood model of plain Lake area is established to analyze the risk of flood disaster.According to the natural conditions and water conservancy facilities of the study area,the study area is divided into drainage areas through hydrological analysis,and the divided drainage areas are generalized into virtual reservoir model.The divided drainage areas are generalized into virtual reservoir model.Based on SCS model,river network hydrodynamic model and drainage water calculation formula,the rainfall flood model of plain Lake area is established,SCS model is used to calculate rainfall runoff,generalizing lakes,river sections,pumping stations and culverts respectively.River network hydrodynamic model is used to simulate the regulation and storage process of lakes,and the relationship between water quantity in drainage area is analyzed.The water level volume relationship of each drainage area is obtained by using the results of design rainstorm and design flood,Combined with the drainage capacity of the drainage area,the change process of water storage in the drainage area is determined.According to the house elevation,the flood inundation range of the virtual reservoir is calculated,and the flood risk range of the disaster prevention objects in the drainage area is determined.(2)The extraction method of early warning index of flood disaster in plain Lake area is proposed.This paper analyzes the current situation of the early warning index,selects the critical rainfall index as the early warning index of flood disaster,and analyzes various methods of calculating the critical rainfall.According to the actual situation of the study area,combined with the rainfall water level curve calculated by the plain Lake area rainfall flood model,the 12 h,1D and 3D rainfall warning indexes of each village are determined,which provides technical support for the release of warning information.(3)Taking Jingzhou District as an example,the real-time warning mechanism of flood disaster is constructed.Based on the flood disaster risk rating system and rainfall warning index,combined with the real-time rainfall forecast of WRF model,the disaster causing curve from rainfall to villages in the drainage area is established.Through the curve,the disaster causing villages under different rainfall conditions can be obtained,and the flood disaster real-time warning of disaster prevention objects can be realized.