Risk Analysis And Early Warning Of Flash Flood Disaster In Longjiang River Basin

Due to the change of climate,mountain torrents have occurred frequently in recent years.Flood disasters,not only caused devastating damage to infrastructures,but also posed a great threat to the safety of people's life,have become one of the important factors restricting the sustainable economic and social development in mountainous and hilly area.It has aroused widespread concern and high attention of the whole society that how to improve the level of flood risk management in small watershed,effectively reduce the casualties and economic losses caused by flash floods,and improve the safety level of flood control.According to the world bank loan project "in Jinggangshan City,long town Longjiang River flood disaster warning system",according to the Longjiang River Basin forest reservoir downstream in densely populated areas,to carry out risk analysis and early warning of flood disasters in Longjiang River Basin,the main contents are as follows:(1)study the disaster process of caused Joe forest Reservoir Dam Overtopping and dam break by the deluge,gate can't be opened normally,the foundation weakening and so on.At the same time,calculated and confirmed the the main hazard factor of exceeding the standard flood and weakening Foundation and so on,based on the analysis of the downstream of Longjiang River Basin flood disaster reason,Qiaolin reservoir disaster model.(2)based on the hydrodynamic theory,established the dam break flood analysis model,and the model was calibrated and validated by the results of model design of river regulation engineering;calculated and analyzed the various possible the flood routing processes of dam outbursting mode,shape,and the way of flow.(3)application of event tree,analyzed risk ratio caused by flash floods disasters on the Longjiang River Basin flood disaster;estimated the loss of life and property downstream personnel dam dam break mode may cause.Based on the analysis results of risk rate and disaster consequence,the risk analysis of disaster was carried out,and the risk degree of each region in the basin was determined.(4)according to the area of the Longjiang River rainstorm characteristics,geological conditions and the basin risk,formulated early warning plan for mountain flood of Longjiang river forest water reservoir downstream in densely populated areas,as the index of water level,foundation weakening degree and rainfall,according to the severity of the mountain flood disasters and classification warningof emergency.