Study On The Assessment And Regionalization Of Agricultural Drought Risk In Henan Province

In recent years,drought disasters occurred frequently and severely in Henan province,causing a more and more huge loss in crop yield and agriculture drinking water.Drought has been an important factor restricting the sustainable development of agriculture and social economy in Henan province.Henan Province is one of main crop supplying area in China.This study will combine the natural characteristics and social characteristics of drought.And by using ArcGIS technology to construct a regional drought disaster risk assessment model with the hazard,exposure,vulnerability and emergency response and recovery capability.On this basis,the model will be applied to the risk zoning of drought disaster in Henan Province,and the results are verified by the historical drought disaster data.The main research contents and results include the following aspects:(1)Drought disaster risk assessment index system includes the factor layer and the index layer.The factor layer included hazard formative factor,vulnerability of disaster environment,bearing disaster exposure and capacity of drought resistance.And the last layer is the index layer.Among them,the index of hazard formative factor is the standard precipitation index(SPI);the index of the vulnerability of disaster environment is depend on the evaporation,the soil texture and the depth of groundwater;the index of the bearing disaster exposure is depend on the density of population,economic density,the proportion of arable land area;the index of the capacity of drought resistance is depend on the drought resistant investment and the proportion of irrigated area.(2)The natural character including the hazard formative factor and the vulnerability of disaster environment.The evaluation result of hazard formative factor in Henan Province is that the disaster risk factors is divided into five risk areas.Anyang where the north area of Henan,Zhengzhou and Xuchang where the middle area of Henan,are the most high risk area.Jiyuan and Jiaozuo where the north area of Henan,Xinyang where the south area of Henan are the mid-high risk area.The rest of the region is the middle of the risk area.Spatial distribution is characterized by the south to the North,and it is gradually increased.Distribution characteristics and the annual precipitation from north to south in Henan had a significant relationship,the annual precipitation in Henan is gradually increased,and distribution characteristics and the temperature also had a significant relationship.The evaluation of disaster environment vulnerability in Henan is that the high vulnerability areas and the mid-high vulnerability areas were mainly distributed in the northern part of Henan.Including Sanmenxia,Nanyang where the west area of Henan,and Jiyuan,Jiaozuo,Anyang,Puyang where the north area of Henan,and Zhengzhou,Pingdingshan the middle area of Henan.Because in these areas the precipitation is small,evaporation is large,soil texture is poor and depth of groundwater is deep.Low vulnerability areas and low-med vulnerability areas were mainly distributed in the east area of Henan,for example Shangqiu,and the south area of Henan,for example Zhoukou,Zhumadian and Xinyang.The Vulnerability of spatial distribution characteristics were gradually increased from south to north and from east to west.(3)The social character including exposure of the hazard bearing body and drought resistance and disaster reduction ability.The exposure of the hazard bearing body in Henan Province is that the exposure of the hazard bearing body is divided into five risk areas.Low exposure area and middle exposure area lied in Sanmenxia and Luoyang where the west area of Henan,Nanyang area,Xinyang where the south area of Henan.Mid-high exposure area and high exposure area lied in the north and mid-east area of Henan.Because no matter from the terrain,rivers,climate and other natural conditions,or from agriculture,industry,urban development and so on.The center area of Henan was in a dominant position,and the population density,economic density and the proportion of arable land area were the higtest in Henan.Spatial distribution is characterized by the west to the east,and exposure is gradually increased.The of drought resistance and disaster reduction ability in Henan Province is that the north area of Henan and the west area of Henan were the high area of drought resistance and disaster reduction,drought resistant investment funds and the proportion of irrigated area were the largest in Henan,so it was the high area of drought resistance and disaster reduction.The southwest area of Henan,middle area of Henan,east area of Henan were the middle area of drought resistance and disaster reduction,it also was the mid-high area of drought resistance and disaster reduction.Most the south area were the mid-low area and low capacity of drought resistance and disaster reduction.Spatial distribution is characterized by the south to the north,and level and ability of drought resistance and disaster reduction is gradually increased.(4)The distribution characteristics of agricultural high drought rist in the North and Eest district,and low drought rist in the South and west district.The high risk areas of drought and mid-high risk areas mainly concentrated in the northern and central in Henan,the northern area in Henan was mainly caused by natural factors,its average annual precipitation was small,and the evaporation was large.High risk areas of in the middle in Henan was the result of the interaction of natural and social factors,risk and vulnerability were larger,population density,economic density,the proportion of arable land of index were higher,exposure was the largest in Henan.The eastern of Henan was the middle risk areas.The western,the southwest and the southern of in Henan were med-low risk areas.The risk and vulnerability of the western areas in Henan were higher,but the exposure was the lowest,and the ability of drought and disaster reduction was the strongest.The natural condition is superior in the southwest and the south in Henan,the rainfall was abundant,exposure of the disaster body is low,and the ability of disaster prevention and mitigation was medium,they were low risk areas and med-low risk areas.The risk compartment of agricultural drought in Henan was consistent with the results of the verification.The paper used the dry disaster risk constitute the four factors of the hazard formative factors,vulnerability of disaster environment,disaster bearing body exposure and drought mitigation capacity to set up a system of risk assessment.The natural and the social attribute of the drought disaster were coupled to implement the drought risk assessment and result visualization of henan province.Thus,based on local conditions,people can take prevention and mitigation measures to reduces the losses caused by drought.