Land Use Change And Ecological Security In Tonghua City, China

This article chooses the typical area of Changbai mountain Tonghua City as a research area, integrating Landsat TM/ETM+remote sensing images and GIS technology, land use of Tonghua City in1986and2008are obtained. The speed, structure and spatial pattern of land use change in Tonghua City are revealed in detail and the main reasons of land use changes are discussed briefly. According to the PSR framework model, the ecological safety evaluation system of Tonghua City is established. The entropy method is employed to determine the index weight, and the ecological security comprehensive index model is used to evaluate the ecological security of the study area. Four rational suggestions are proposed in this thesis.The main conclusions are listed as follows:First, woodlands and cultivated land are the dominant land use types in Tonghua City. From1986to2008, build-up land and water area showed a growing trend, while the area of other lands decreased. As a whole, land use change in the study area is not significant. With respect to the conversion characteristic of land use, dramatic internal structural change were found, which were driven by human activities and social factors.Second, the ecological security of Tonghua City in1986was at the early warning level. In2008, ecological security situation rise to a safer level. The contribution rate of pressure layers in the ecological security evaluation systems for two years are the largest, but decreased in2008. Contribution rate of the ecological environment reduced, while that of response layer increased. In2008, the contribution rate of the pollution control capacity was much higher than that in1986, indicating that the environmental pollution controlling was effective. Three factors index values of the pressure layer increased, while the ecological environment condition tended to be worse.Finally, considering land use and ecological security situation in the study area, this article presents four proposals:1) continuing to control population growth, which may reduce pressure on land resource;2) increasing the investment fund to manage "three wastes" and lessen pressure on the environment. Moreover, both symptoms and root causes of the environment problems must be solved, and the ecological compensation mechanism are required. In the process of natural resources development and use, the ecological environment should be protected;3) strengthening the public’s awareness of environmental protection and improving the legal system of environment protection.