Changes Of River-Lake Environment And Local Water Conservancy In The Middle Reaches Of Fenhe River During Ming And Qing Dynasties

Environmental issues is the hotspot of study in the development of social and economy in modern times, and the problems of water environment is especially the social focus of concern. For Shanxi province is concerned, sustainable development of mineral resources and reasonable distribution and utilization of water resources is the direction and requirements of the sustainable development currently and in the future, and it aslo gives more influence to the adjustment the industrial structure in Shanxi province. In view of this, by using historical document combined with investigation, this paper trys to recuperate the changes of river-lake environment in the middle reaches of Fenhe river during Ming and Qing periods, and aslo gives a study on the temporal-spatial distribution of the flood disasters and the construction of water conservancy projects in this area. This paper will be favorable for decision-making on the utilization of water resource and construction of the water conservancy projects.Through collecting and analysis on the relevant historical documents, we found that the river-lake environment in the middle reaches of Fenhe river worsened quickly during Ming and Qing periods, which is reflected in three aspects:(1) runoff decreased and lakes disappeared quickly;(2) the sediment concentration increasing quickly;(3) frequent river diversion. In addition to be influenced by the natural factors, human factors also played an important role in the process of the evolution of the river-lake environment in the middle reaches of Fenhe river during Ming and Qing periods, especially the critical ruin to the vegetation and seriously soil erosion caused by the extensive cultivation and construction of the water conservancy projects which gave an important impact on the evolution of the river-lake environment in the middle reaches of Fenhe river.Through the analysis on the temporal change and spatial distribution of the flood disasters, it shows that there had a flood every2.5years in the middle reaches of Fenhe river during Ming and Qing periods, and it becomes more frequently in Qing period. Further more, the big flood disasters often occurred in the relative concentration on the time, especially in the nineteenth century, there was at least four flood disasters happened every ten years. Through the spatial distribution of the flood disasters, we can see that Taiyuan basin became to be the central place in where flood disasters often took place,and this is relevant with the frequent overflow of Fenhe river and its tributaries, but at the edge of this area, such as Xugou and ShouYang county, there was few flood disasters happened, and it also relevant with the heavy rain happened in the mountains.It goes to a peak for the construction of water conservancy projects in the middle reaches of Fenhe river during Ming and Qing periods. Choosing tunnels and dams as two important factors, it shows that there was a large scale construction of tunnels and dams in this area during Ming and Qing periods, especially after Qianlong period. To some extent, building of the tunnels and dams plays an important role to the field irrigation and city-agriculture protection, but the frequent flood disasters which caused by extensive cultivation aslo bring serious damage to them.