| Natural disasters have been a major factor affecting human production and life.Since the 1950 s,the degree of natural disaster has gradually increased.On the one hand,global climate change has led to the frequent occurrence of extreme weather events.On the other hand,Population and economic agglomeration,the impact of these two factors to the natural disaster caused by the loss of exponential growth.At present,natural disasters have become a major constraint to human development,disaster prevention and mitigation has a long way to go.Chongqing is located in the subtropical monsoon climate zone,by the southeast monsoon,southwest monsoon and winter monsoon alternately control,frequent summer rainstorms,winds and hail disasters often occur,autumn and winter low temperature even rain and other natural disasters in most areas also have a significant impact.Chongqing is also subject to subtropical high pressure belt control,summer prone to high temperature and drought weather.The terrain of Chongqing is mainly composed of mountainous,hilly,terrace,valley and so on.The geological structure is complex and the fragility of surface lithology is high.Since the municipality directly under the jurisdiction of Chongqing,the rapid economic development,human damage to the surface further intensified,leading to new disasters continue to appear.Natural disasters have seriously hampered the development of Chongqing’s economy,so it is necessary to study the natural disaster zoning in Chongqing.Key words: natural disasters;regional differentiation;regional combination;comprehensive regionalization;Chongqing Municipality.Based on the previous research results and the existing natural disaster data of Chongqing City,this paper studies the regional distribution and characteristics of natural disasters in Chongqing according to the theory of natural disaster system and the theory of geographical division using mathematical statistics,spatial analysis and geographical division And the formation of the mechanism,the natural disaster regional differentiation and combination,comprehensive evaluation of Chongqing natural disaster index,on this basis,Chongqing natural disaster comprehensive zoning program.The main conclusions of this study are as follows:(1)Temporal and spatial distribution characteristics of natural disasters in Chongqing.The main types of natural disasters in Chongqing are torrential rain,drought,hail,low temperature rain,landslides,landslides and mudslides.They are distributed in all regions,but there are significant regional differences in the number,size,frequency,intensity and structure of their occurrence.Wanzhou District and Yunyang County and other places the largest number of geological disasters,per square kilometer of geological disasters more than 13;followed by the central Chongqing Fuling,longevity and western Chongqing Hechuan and other places;western Chongqing and Chongqing southeast of the unitary Yang and Xiushan belong to relatively few geological disasters.In addition to Wansheng and the city,the frequency of drought in the rest of Chongqing is very high,especially in the Yangtze River,Jialing River and Qijiang River valley is particularly serious drought;spring drought in the western Chongqing,summer drought in the northeast of Chongqing and western Chongqing In the northeastern part of the northeastern Chongqing and Chongqing,the winter drought is mostly in the northeastern part of Chongqing.There are three high-value areas in the rainstorm.The floods are in the area along the Yangtze River and the low-lying areas Yangtze River,Jialing River,Qijiang River,Wujiang River,Daning River and other coastal areas;high temperature in the middle of Chongqing and western low-lying areas,especially along the river valley area of high temperature days,strong;strong winds in the northeast of Chongqing,especially Is Wanzhou and Wuxi Creek;hail more in Youyang and Xiushan.(2)Regional differentiation and combination of natural disasters in Chongqing.The regional differentiation of natural disasters in Chongqing is the local and local regional differentiation laws caused by geomorphology,climate,geological structure,lithology and socio-economic factors in the context of latitudinal zonal laws.Due to the limitation of the macroscopic pattern of the landforms,there are significant differences in the regional natural disasters between the northeastern part of Chongqing and the low mountainous areas in the southeastern part of Chongqing and in the hilly areas of central and western Chongqing.The former has many kinds of natural disasters,large intensity and vertical differentiation.The latter has many natural disasters,and the intensity is small,but the natural disaster is heavy due to the distribution in the densely populated areas.Within these two natural disaster areas,small terrain and microclimate caused a smaller spatial scale of natural disaster differentiation.There are significant differences in the regional combination of natural disasters in Chongqing,and the northeastern Chongqing area is a combination of drought and dry geothermal hills,autumn and winter drought and drought,and the southeastern Chongqing area is a dry hail hail thunderstorm and continuous rain and rain disaster combination area.Kaixian-Liangping-Dianjiang area is a mountain Geological and disaster combination area;Wanzhou-Zhongxian-Yunyang area for the high temperature and drought floods flood hail drought drought disaster combination area;Chongqing City,the main city of nine districts-Bishan-Jiangjin high temperature and drought flood disaster disaster zone;For the drought and drought in the drought and rain and rain in the spring and summer drought zone.(3)Natural Disaster Composite Index.Based on the theory of natural disaster system,based on the analysis of GIS spatial analysis,based on the analysis of Chongqing city natural disaster disaster environment sensitivity,hazard factor risk and disaster tolerance,the weighted comprehensive evaluation method is used to calculate the natural disaster Index to reflect the characteristics,nature and spatial differences of the natural disaster system in Chongqing.The comprehensive index of natural disaster is located in the areas of Wuxi,Wushan,Fengjie,Chengkou,Wanzhou and Yunyang,and the comprehensive index of natural disasters is more than 2.7,followed by the main urban area and its surrounding areas.The natural disaster comprehensive index is located in Youyang,Xiushan,Qianjiang and Pengshui in the southeast of Chongqing.The comprehensive index of natural disaster is less than 1.7,and the natural disaster index is between 1.7 and 2.7.(4)According to the regional differences of the comprehensive index of natural disasters in Chongqing and the regional differentiation and combination of natural disasters,the natural disaster area of Chongqing is divided into the boundary of the geography of natural geography and natural disaster.First of all,mainly based on macro-disaster environment,regional natural disaster combination and characteristics,divided into the first level of natural disaster area;and then mainly based on regional natural disaster portfolio,natural disaster intensity and frequency,in the first level of natural disaster area based on the second Class natural disaster area.Which will be divided into Chongqing,Chongqing and Chongqing southeast of Zhongshan low mountain natural disaster area(I)and Yuzhong and western hills and low mountain natural disaster area(II)two primary natural disaster area. |
