Study On Land Use And Environmental Effects In The Fenhe Upriver Watershed During Ming Dynasty

With the increasingly serious ecological crises, to research the interruption of human activities' to watershed environment has attracted more and more global scientists' attention. However, up to now, it is still insufficient in studying the influences of human activities in historical periods to upriver watershed environment from the angle of ecological safety by using the modern physical geographic thoughts and methods. The upper reaches of river is an important ecological defense to the whole drainage basin. Any environmental change of the upper reaches will swiftly pass to the middle and lower reaches. For instance, soil and water erosion in Fenhe upriver watershed of Shanxi once aggravated the floods disaster in its middle and lower reaches in historical periods. Therefore, it has became a research highlight for many scholars' to study the complicated change process and its controlling mechanism of the relationship between man and nature in watershed from the perspective of historical geography, aimed at the issues of population, resources, environment and development of drainage basin.Fenhe upriver watershed is a typically ecological fragile zone in the Loess Plateau and had been a transition area of cropland and grassland in historical times. From the beginning of Ming Dynasty, a series of policies executed by the government, wars and human activities had caused its land cover changed enormously. The whole Ming Dynasty is just a period in Fenhe upper reaches when its land use and land coverage changed dramatically.Based on the analysis of tons of historical documents, the author tries his best to combine the change of natural environment on upper reaches in historical periods and the function of human activities and establishes an interactive mechanism (driving factor - land use/land coverage change -influence to environment) on the basic change of land use in historical times.The whole text includes six chapters, except the postscript.In the first chapter, general description of land use, the author gives a brief introduction to the purpose, meaning and methods of the research, domestic and overseas academic trends of land use.In the second chapter, the author introduces the range of upriver watershed and its characteristics of geographical environment, then recover its geographical environment before Ming Dynasty.In the third chapter, the author analyzes the change of land use in the upper reaches of Fenhe river specifically, divides the land of Fenhe upriver watershed into woodland, grassland, cropland and the land for defense facilities. The change of land use is principally embodied by the facts that colony land and arable land expanded toward mountainous areas, extensive plough in steep slope had been considerably severe, garrison established a large number of defense facilities, forests have been seriously destroyed and the pasture degraded.In the fourth chapter, the author analyzes the major driving factors for change of land use in Fenhe upriver watershed. The major driving factors are human and natural factors. The human factor includes colony land policy, forest policy, tax policy, war and human's migration to mountainous areas. The author believes that natural conditions are the precondition for the land use change, and human factor is the major reason to seriously change the land use in Fenhe upriver wetershed.In the fifth chapter, the author analyzes the environmental effect brought by the change of land use. The virgin forest in the upper reaches has been destroyed seriously. With the woodland shrinking continuously, serious water and soil erosion occurs frequently. The terrain tends to be fragmented. Therefore, the living environment for animals or others species has been affected, for instance, the bear in the upper reaches has disappeared. Loess Plateau, as a typical ecological fragile area in North China, unreasonable development causing environmental problems is unavoidable.In the sixth chapter, the author draws a conclusion on the basis of the above research. The author analyzes the functions of natural and human factors in local economic and social development by appraising the environmental change of Fenhe upriver watershed in Ming Dynasty and delivers his suggestions to build a harmonious relationship between man and nature in future.