The Land Use Change And Eco-environment Effect Of The Middle Reaches Of The Tarim River

This article mainly investigates the middle reaches of Tarim River, because of the fragility of the ecological environment and the high frequence of human activity in this region. Through the remote sensing , the GIS technology and the field investigation ,we gained the land utilization data of the research area in 1973, in 1990, in 2000 and in 2008.With the land utilization change dynamic model and the ecosystem service function value estimate method's support, we analyzed the land utilization's space and time change trend and the change actuation factor of this region in recent 35 years. On this basis, we estimated the value of the land utilization's ecology service. Together with our previous research, we contrasted the ecology service' value of the middle reaches with that of the lower reaches ,by which we can analyze the change characteristic of the ecological environment and provide the reference to the ground's sustainable use and the ecological environmental protection of the middle and the whole region of Tarim River. The main findings are as follows:1. In1973-2008, the land utilization of the middle reaches of Tarim River undertook remarkable changes. The farming and the lawn area increased while the forest land, the water area and the unused area decreased. The main shift types are as follows: the water area and the unused area translated to the forest land and the lawn, the forest land translated to the unused area and the farmland, the lawn translated to the forest land and the unused area, the farmland translated to the forest land.2. In1973-2008, the integrate tendency and the condition index of the land utilization in the middle reaches of Tarim River develop towards 0,indicating that the land utilization is at the equilibrium state from 1973 to 2008 and get optimized by time. At the same time, the land utilization degree is high and increases gradually in this period. As a whole, the develop of the middle reaches of Tarim River goes towards improving the agricultural economy. 3. In 1973-2008, the economic interest, the technology and the capital spending were the main reasons for the changes of the land utilization in the middle reaches of Tarim River while natural causes such as the temperature and the precipitation contributed a little.4. In 1973-2008, the total value of the ecological service undertook a decreasing trend ,while the value has increased slowly since 2000,indicating that the ecological environment has developed gradually since then. Recording to the ecological service's changes of various land utilization types, we can see that the farmland and the lawn are increasing while the forest land, the water area and the unused land take a decreasing trend.5. In 1973-2008, the total value of the ecological service in the uper and lower reaches of Tarim River undertook a decreasing trend. As a whole, the total value undertakes a decreasing trend and the ecological environment is worsening gradually while the total value of the ecological service in Tarim River mainly comes from the forest land and the water areas.