Risk Assessment And Regionalization Of Drought Disaster In Jiangxi Province

In recent years,drought has been frequently reported in large areas,and Drought Monitoring,prediction and risk assessment have become a hot research field at home and abroad.Jiangxi Province,located in the south of the Yangtze River,is a sub tropical monsoon climate,with the characteristics of Spring and autumn,winter and summer long,winter cold,summer heat.Some studies show that drought is the second major disaster in Jiangxi Province.Therefore,it is of great significance to study the drought risk regionalization and control measures in Jiangxi Province.Standardized precipitation vapor and dispersion index(SPEI)is calculated to evaluate the spatial and temporal distribution of drought.Select disaster factors risk,pregnancy environmental vulnerability,bearing body exposure and disaster prevention and mitigation ability four factors and 16 indicators,using hierarchical analysis to determine the weight,and then through the weighted comprehensive evaluation and natural disaster index drought risk zoning map,and through the risk map and indicators,put forward corresponding Suggestions for drought prevention and control in Jiangxi province.The conclusion is reached as follows:(1)Based on the standardized precipitation evapotranspiration index,the dry early intensity of Jiangxi Province from 1959 to 2018 is analyzed.The results are as follows: The dry early intensity of Jiangxi province shows a decreasing trend on the whole(on an annual scale);Drought occurred in Jiangxi Province from 1959 to 2018 in a total of 49 years(including light,moderate,severe and special drought),the frequency of drought was 81.7%.The areas with the highest frequency of droughts are mainly in Yichun,Guangchang County,Yushan County and Suichuan County.(2)The Risk Index of disaster-causing factor selects the annual average precipitationandthe annual average temperature: the Environmental Vulnerability Index of disaster-inducing environment selects the quantity of surface water resources,the quantity of underground water resources,the soil type and the Elevation Index: the Exposure Index of disaster-bearing body selects the Cash crop per unit area sowing yield,the crop sowing area,the economic density and the population density;The index of Disaster Prevention and reduction capability selects the amount of small hydropower,the area of effective irrigation,the per capita income of farmers,the capacity of water supply,the financial income and the number of drought-resistant equipment(electromechanical well).(3)The four influencing factors of drought were evaluated.(a)risk assessment of disaster-causing factors: The risk spatial division of disaster-causing factors in Jiangxi Province is high in the middle,but low in the West and northeast.Level1(low-risk zone)and Level 2(medium-low-risk zone)are Pingxiang,western Ji’an,southern Jiujiang,Shangrao and Yingtan cities,and eastern Jingdezhen,with a Risk Index between 0 and 0.38.Level 3(Middle Risk Zone)is in Fuzhou,Jiangxi,Yichun,Western Shangrao and Central Jingdezhen,with a risk index between 0.38 and0.49.Category 4(medium to high risk areas)is central Ji’an,Xinyu,southern Nanchang and other parts of Ganzhou,with a risk index of 0.49-0.61.Level 5(high risk area)is north of Ganzhou and south of Ji’an with a risk index between 0.61 and1.(b)Vulnerability Assessment of disaster-prone Environment: The vulnerability of disaster-prone environment in Jiangxi Province shows a decreasing trend from north to south.Of these,Tier 1(low risk area)is Ganzhou with a vulnerability index of0.07-0.3.Level II(medium to low risk area)covers parts of Ji’an,Shangrao and Fuzhou,Jiangxi.Tier 3(medium risk area)covers Yichun,central Jiujiang and parts of Fuzhou,Jiangxi with a vulnerability index of 0.44-0.53.Level 4(medium and high risk areas)is Jiujiang with a vulnerability index of 0.53-0.66.Level 5(high-risk areas)is Jingdezhen,Yingtan,Nanchang,Xinyu and Pingxiang,with a vulnerability index of0.66-0.92.(c)Exposure assessment of hazard bearing body: one level(low risk area)is Xinyu,the exposure index is between 0.09 and 0.22.Category II(low-to-medium risk areas)was Yingtan city and Pingxiang with an exposure index of 0.2-0.38.Category III(medium risk area)is Jingdezhen,Jiujiang,Shangrao and Fuzhou,Jiangxi,with an exposure index of 0.38-0.43.Category 4(medium to high risk areas)are Nanchang,Ganzhou and Ji’an,with an exposure index of 0.49 to 0.54.Category5(High Risk Area)is Yichun with a exposure index of 0.54 to 0.72.(d)Assessment of disaster prevention and reduction capacity: the first level(low risk)is Yichun,and the risk index of disaster prevention and reduction capacity is between 0.309 and 0.427.The second level(medium and low risk)is Ji’an,and the risk index is between 0.427 and 0.544.The third level(risk in disaster prevention and reduction capacity)is Ganzhou,Shangrao and Nanchang,and the risk index is between 0.544 and 0.608.Level 4(High Risk in disaster prevention and mitigation capacity)is Jiujiang,with a risk index of 0.608-0.777.Level 5(High Risk of disaster prevention and reduction capacity)is Jingdezhen,Yingtan,Xinyu,Pingxiang and Fuzhou,Jiangxi,and the risk index of disaster prevention and reduction capacity is between 0.777 and 0.885.(4)The characteristics of drought risk regionalization in Jiangxi province: The middle and northernmost parts of Jiangxi province are at high risk.The high risk areas were the south of Yichun,Nanchang and Ji’an and the north of Ganzhou,with a risk index of 0.558-0.71.The medium to high risk areas are north of Yichun,west of Fuzhou,Jiangxi,north of Ji’an,Nanchang and middle of Ganzhou,with a risk index of0.515 to 0.473.The medium risk areas were Xinyu,the eastern part of Fuzhou,Jiangxi and the western part of Yingtan city,with a risk index of 0.473-0.515.The low-to-medium risk areas were the eastern part of Pingxiang,Shangrao and the eastern part of Yingtan city,with a risk index of 0.411-0.473.The low risk areas are western Pingxiang and central Jiujiang,with a risk index of 0.558-0.71.(5)According to the drought risk zoning map of Jiangxi Province,the weak indicators of each risk area are analyzed to provide some suggestions for regional drought prevention and drought.