The Research Of Locusts Plague In Gansu Area In Ming&Qing Dynasties

Since ancient times,the locust plague,floods and droughts have been known as the three natural disasters in China,which have been a serious threat to agricultural production and social stability.Most of the existing researches focus on intergrated research of locust plague,and there are few researchs on generation and regional studies.Especially in regional studies,the main subjects are Hebei,Shandong and Henan,followed by Jiangsu,Anhui and Hubei,and finally Shanxi and Shaanxi.And as one of the birthplace of early agriculture in Chinese nation,Gansu is important strategic area.It has a long history of agriculture and rich historical records.But there are few studies on locust infestation in Gansu province.Based on this,this paper uses all kinds of historical records,completes the data of locust plague in Gansu area during the Ming and Qing dynasties,analyzes the spatial-temporal characteristics of the locust plague.Furthermore,the formation conditions of locust plague were discussed in detail,and the great influence of locust plague on Gansu area was analyzed.Finally,the results of the treatment of locusts in the Ming and Qing dynasties were summarized.The paper is divided into four parts.The first chapter is the introduction,which summarizes the research achievements of predecessors and clarifies the reasons,methods,goals and significance,innovation and research difficulties of this paper.The second chapter collects,finds and collates various historical materials,comprehensively and systematically concludes the occurrence data of Gansu locust plague.In Gansu province,54 locust plague occur during the Ming and Qing dynasties,which occur basically once in ten years.Locust plague is active in the summer and autumn.According to the locust occurrence frequency,the Ming and Qing dynasty are divided into three stages.In the beginning of dynasty,locust occurrence frequency is low and has smaller impact.Then the frequency and influence of locust plague peak from the mid to late of the dynasty.By comparison of the frequency of locust plague in Longdong,Longnan,central region and Hexi region,we conclude Longdong,Longnan and Hexi are the most frequent locust plague areas,and the central region follows.The third chapter mainly discusses the causes of locust plague in Gansu province and analyzes its natural and social factors.Among natural factors,the occurrence of drought,flood and locust disaster are closely related,usually one after the other or with it.The alternation of floods and droughts will form a favorable environment for locust plague.The occurrence of locust plague and drought has higher homogeneity,while flood will inhibit the occurrence of locust plague.The relationship between locust plague and temperature change is not significant,and "Micro Ice Age" in the Ming and Qing dynasty can lead to frequent droughts,and then promote the occurrence of locust plague.Among social factors,the influence of political environment on locust plague and disaster-relief is huge,and the development of land reclamation and famine,war and population growth will also have a great impact on the occurrence of locust plague.The fourth chapter mainly discusses the locust plague causes far-reaching impact to Gansu area in the Ming and Qing dynasties,frequent locust plague directly leads to the agricultural production failure and food shortages,which in turn leads to famine.Especially the flood,drought and locust occurring alternatively,which cause major famine,economy collapse,the destitute of people and seriously affect social stability,even leading to the replacement of dynasties.