The Analysis And Evaluation Of Mountain Torrent Disaster For Villages Along The Feng River Upstream In Chang'an County

In our country,the area of mountains account for 2/3 of the area of whole country.Because of the large population density and frequent rain in mountain area,flash floods will be raised and happen quickly.Mountain flash floods not only cause devastating damage to our city infrastructure,but also threatens people's life and property safety,so the analysis of flash flood disaster is of great significance in order to minimize casualties and property losses.The detail contents are as follows:1.Evaluation of rainstorm flood in small watershed in the mountain flood disaster prevention area.Based on Handbook of Applied Hydrology in Xi'an City,this paper has analyzed and calculated the design rainstorm characteristic value of small watershed standard duration,the design rainstorm and the characteristic value of corresponding flood for the duration of concentration flow time in small watershed to evaluate the characteristics of steep rise and fall,short duration and heavy rainfall in small mountain watershed's flood.2.Evaluate current status of flood control capacity for the prevention areas of Chang'an District.Evaluation mainly includes the frequency analysis of the flow corresponding to disaster water level,five kinds of typical frequency flood peak water level,distribution situation of population and housing along height and analyze the flood prevention capacity of disaster prevention object by making the control section water level-flow-population relationship chart-AKA the flood control evaluation chart.3.Divide the risk level for the danger zones of Chang'an District.The danger zones are divided into three level-Very High,High and Dangerous and determine the transfer route&temporary placement scientifically and reasonable.4.Analyze rainfall warning indicators for the disaster prevention object,especially the critical rainfall when the watershed soil moisture content is in the status of dry,average and wet.Determine the rainfall warning indicators of:Ready to transfer" and "Immediate transfer",finally plot the danger zone division map and the critical line map of early warning rainfall.The characteristics of mountain flood mainly include widespread,regional obvious,occur frequently or difficult to predict and so on.Moreover,the mountain flood usually cause great economic loss in the local area.Therefore,the research significance of torrential flood is that provide more in-depth and particular information for the prevention areas of mountain torrents.