The Research On Meteorological Disasters In Central Gansu Province In Qing Dynasty

This thesis researches the history of regional dating disasters, mainly discussing the meteorological disasters of the Longzhong area in Qing dynasty.This thesis is composed of three parts; the first part is the first chapter, introducing the natural conditions and the organizational system evolution of this area. Firstly, it defines the study area and explains the administrative organizational system changes respectively from the point of natural geographical scope and administrative division. Secondly, it sets forth the natural geographical conditions of meteorological disasters in this area in terms of climate, topographic features, vegetation and hydrology and so on.The second part includes the second, the third and the fourth chapters. It specifically analyzes the meteorological disasters such as drought, hail, water logging, sandstorm and frost/snow and so on in this area in Qing dynasty. Firstly, the first section of each chapter lists the disaster timeline by collecting and arranging the historical material of meteorological disasters in this area in Qing dynasty from the historical documents. Then, the other sections of each chapter, on the basis of the historical facts put forth by the timeline, analyze statistically the specific types of various meteorological disasters according to the different disaster mechanism. It explores the characteristics of the disasters'occurrence frequency, period and stages through enumerating typical cases, assessing hazards, classifying the disaster level sequence and ensuring the disaster proportion constitution. And thus exposes the occurrence and development regularity of various meteorological disasters. It discusses the changes in a year in the light of the seasonal prevalence and the distribution in months; it analyzes the interannual changes in terms of ten years; it analyzes the geographical distribution in terms of a state or a county. Thus discloses the space-time characteristics of the Longzhong meteorological disasters in Qing dynasty. It analyzes the cause of disasters, considering both natural and anthropic factors and uniting the meteorological changes in Qing dynasty and the crops'growth cycle in this area.The fifth chapter is the third part. It is the pandect of meteorological disasters in Longzhong in Qing dynasty. Firstly it concludes that the meteorological disasters in this area in Qing dynasty are mainly moderate disasters and drought disasters. Secondly, it exposes the characteristics of the disasters'wide coverage, severe consequence, their distinct seasonality, their quickened frequency, shortened cycle, the simultaneous occurrence of many disasters, their close interrelation and their obvious around-secondary by analyzing the overall space-time characteristics of this area's meteorological disasters in Qing dynasty. In the meantime, it states that the climatic changes and natural causes are the principal cause of the high frequency of meteorological disasters in this area in Qing dynasty. Man's unreasonable exploitation is an important factor that aggravates the disasters. Lastly it proposes some specific measures of guarding against and lightening various meteorological disasters through rethinking the heavy losses by those disasters in this area in Qing dynasty and learning from the historical failures, hoping to benefit the sustainable development of social economy of this area.