Assessment On Integrated Risk Of Drought And Flood Disasters In Huai River Basin

Drought and waterlogging disasters are the most frequent and severe natural disasters occurred in the Huai River from history.It is an important factor in social and economic development.Researching the risk zoning of drought and waterlogging disaster is significant for accessing to effective prevention and treatment,because it will help management to make prevention strategies scientifically and arrange for disaster of local conditions quickly.It will reduce casualties,reducing industrial and agricultural economic losses and avoid environmental degradation which was caused by droughts and flood.Extreme drought and waterlogging events occur in Huai River Basin frequently and seriously,such as "drought and waterlogging coexist" and"drought-waterlogging abrupt alternation”,under the background of global climate change.In this paper,we defined" drought-waterlogging disaster "as in the place not only drought disaster risk,but also waterlogging disaster risk.Drought-waterlogging disaster risk is assessed and zoned in this paper by using variety of techniques.Through precipitation anomalies to analysis historical meteorological data,make a temporal-spatial analysis of the results by using orthogonal decomposition method.Using GIS technology analysis the spatial characteristics and using wavelet method and trend function analysis the temporal characteristics.The conclusions as follows:Terrain,precipitation,evapotranspiration are the closely relationship to the distribution of drought and waterlogging.The relationship in the nearly 60 years be more closely,but the correlation rise slowly.In the nearly 60 years,the spatial characteristics has affected by the distribution of land and sea as a down trend,with the oscillation period of about four years period.According to waterlogging disaster risk and drought disaster risk forming principle,based on the natural and socio-economic conditions in Huai River Basin,indicators were selected from hazard,exposure,vulnerability and mitigation,using set pair analysis law,entropy weight method and gridding GIS technology to build the Huai River Basin drought-waterlogging disaster risk assessment model.The integrated risk zoning of drought-waterlogging disaster was drawn by using spatial analysis and gridding GIS.The results show that:the integrated drought-waterlogging disaster risk distribute as warp Characteristic;eastern and western basin belong to low risk,central belong to high risk,southern basin mainly higher than northern basin;spatial grid statistics data shows that the characteristic of risk in Huai River Basin presents a skewed distribution,larger proportion is low or lower disaster risk and smaller proportion is high or higher disaster risk;it is very well for assessing integrated risk of waterlogging-drought disaster by using set pair analysis and natural disaster risk formation theory.The results obtained in this study are specifically intended to support local and national government agencies in water-related disaster management since they are responsible for disaster resource allocation,planning decisions,efforts in public education,and sustainable development planning for economy.