Study On The Evolution And Social Influence Of Multiple Disaster Species In The Ming And Qing Dynasties In Gansu And Qinghai Regions

As the junction of Qinghai-Tibet Plateau and Loess Plateau,Gansu and Qinghai region is sensitive and vulnerable to climate change,which is easily affected by various natural disasters.During the "Little Ice Age" in the Ming and Qing Dynasties,the climate tended to be cold and dry on the whole,and the complex disaster-bearing environment and disaster-bearing body distribution pattern formed the unique regional distribution of natural disasters in this area.In order to further reveal the evolution trend of disasters affected by the "Little Ice Age" climate in the Ming and Qing dynasties and the degree of social impact,it provides basic reference for the current research on historical disasters.On the basis of collecting and sorting out various historical documents in the area of Gansu and Qinghai,this paper made statistics on the time and place,disaster conditions and characteristics of various disasters in the area during the Ming and Qing Dynasties.With the support of Arc GIS software platform,mathematical statistics,social network analysis,spatial analysis and other methods were adopted.The spatial and temporal distribution of major disasters,the combination characteristics of multiple disasters,the correlation analysis of disasters,and the degree of social impact of multiple disasters and famine in Gansu and Qinghai were analyzed,and the following conclusions were drawn:(1)According to the data collection,in the Ming and Qing dynasties of nearly500 years,natural disasters in Gansu and Qing areas a total of more than 3000 times.Drought,as the primary disaster type,accounted for 31.6% of the total county level disasters and occurred nearly 200 years ago.It was followed by hail(29%),flood(24.4%),cold(12%)and locust(3%).The superposition of multiple disasters occurred for more than 200 years,and a superposition of multiple disasters occurred in nearly 3years,indicating a high frequency of disasters.(2)From the Ming Dynasty to the Qing Dynasty,the frequency of various disasters in the study area showed an increasing trend in 10 years.From the early Ming Dynasty to the middle Ming Dynasty,the change trend of disasters in the Gansu and Qinghai area was small,and from the middle and late Ming Dynasty to the Qing Dynasty,the disaster frequency in the Qing Dynasty was higher than that in the Ming Dynasty.The spatial distribution of disasters in the Gansu and Qing areas is affected by natural and human factors.The density of disasters in the eastern part of the study area is significantly higher than that in the western part of the study area,mainly concentrated in Lanzhou,Huining,Lintao,Linxia,Longxi,Weiyuan,Jingning,Xining,Ledu and other areas in the eastern part of the study area,showing the spatial distribution characteristics of "multi-core,multi-zone".It develops from north to south mainly along rivers and valleys.(3)Through the correlation analysis and network diagram construction among disasters,it is concluded that the disasters are closely related to each other,forming a strong disaster network relationship,and famine is located in the center of disasters,and there is a significant correlation with other disasters.Affected by frequent disasters,the temporal and spatial distribution of famine and disaster distribution in the Gansu and Qinghai areas are similar.Moreover,the regression analysis results show that,except for cold disasters,there is a positive relationship between famine and all types of disasters,and the superposition of multiple disasters is the strongest influence,which indicates that the superposition of multiple disasters is the main factor of famine occurrence in the Gansu and Qinghai areas.(4)The occurrence of multiple kinds of disasters in Gansu and Qing areas mainly resulted in famine and had a great impact on regional development.Famine,as a result of natural disasters,occurred nearly 200 times in the Ming and Qing Dynasties,with a high frequency of more than 800 times,and presented a relatively concentrated distribution in time.It occurred frequently from 1723 to 1820,and was mainly distributed in the east of the study area,with Xining and Lanzhou as the centers in space.The spatio-temporal superposition analysis of multiple disaster species and famine data was made to explore the approximate famine scope affected by multiple disaster species.It was found that the famine areas were mainly concentrated in the middle and late Qing Dynasty and the eastern part of the study area.The superposition of multiple disasters will affect the normal growth of crops,resulting in crop failure or failure,resulting in a large area of famine.When the problem is not alleviated,regional contradictions and conflicts will be caused.According to the statistics of war events in Gansu and Qing areas in the Ming and Qing Dynasties,it is found that they coincide with the main time series of famine,indicating that the superposition of multiple disasters will affect regional stability.