A Study On Northwest Agricultural Development And Ecological Environment Problems In Qin And Han Dynasties

As the worsening of ecological environment in China, the relationship between human and nature, and the ecological environment and sustainable development issues have aroused wide social concern. Although the agricultural development in Qin & Han Dynasties created great success, ecological environment problems can not be ignored. During that period, China's agricultural development was unprecedented both in scale and depth, so, deterioration of the ecological environment exacerbated by the dry climate change, especially in northwest ecologically fragile areas. The ecological environment is essential for the survival of human civilization. In pre-Qin period, rich forest resources and biological diversity and abundant water resources existed. Beautiful ecological environment filled the world. Until Qin and Han Dynasties, because of frequent human activities, environmental issues followed out.During Qin and Han periods, the northwest region had more land but less people and the difficult life environment there. The Huns and other ethnic minority forces have continued to develop and grow. This situation posed serious threat to the Central Plains dynasty. In order to resist the Huns, government stared to encourage people migrated into northwest regions and develop agriculture. Hexi, Hehuang, Hetao and Xiyu were strategic developed in Qin and Han periods. But the development was in great military and mandatory. The development of irrigation and water conservancy were primary means to the agricultural development. It was an efficient way of resisting the Huns and other ethnic minorities'attack. It also strengthened the economic and social stability, and had positive effect on cultural exchanges and communication.At the same time due to excessive reclamation of the land, large grasslands and woodlands have been gradually replaced by farmland, and the number of plant and animal species declining, intense human activities interfered the ecological environment, the environment ultimately break its capacity, soil erosion and land desertification and other ecological problems appeared. Qin & Han Dynasty was the first period during which people migrated into and developed northwest area on a large scale in Chinese ancient history. This period was also a disaster period. This shows that the Northwest agricultural development and ecological environment are closely related to the emergence of the problem. This paper mainly from four areas to study: First, the ecological environment in Pre-Qin Dynasty; Secondly, success that have made in agricultural development in different areas. Again, detailed analysis of ecological problems caused by the agricultural development. Fourth, both positive and negative evaluation on agricultural development as well as the lessons that contemporary development of the western region needed in Qin and Han Dynasties.