Study On Evaluation Index System For Land Ecological Security

After nearly half a century of development, the population has grown rapidly, and the competition in the land is increasingly fierce, so the limited land resources has been unable to meet unlimited demand. In order to meet the demand for land, particularly the needs of the construction sites, large areas of farmland and forest land is converted into construction land. The original land structure and ecological environment is destructed, which is resulting in a series of ecological problems of land. It's a serious impact on regions for sustainable development. The land ecological security evaluation can help people intuitively understand the security situation in the land ecosystem, and is conducive to the sustainable use of land resources to protect the human social and economic development. As a key link, the reasonable of index system of land ecological security evaluation will directly affect the result of evaluation. At home and abroad the present stage there is no uniform standard of the land ecological security index system, the evaluation index systems which have been commonly used also has some defects, and should be improved. Therefore, it is great significance to improve the those evaluation index systems to enable them to more scientific, more rational, and more comprehensive picture of the land ecological security. The land ecological security evaluation can help people intuitively understand the security situation in the land ecosystem, and is conducive to the sustainable use of land resources to protect the human social and economic development. As a key link, the reasonable of index system of land ecological security evaluation will directly affect the result of evaluation. At home and abroad the present stage there is no uniform standard of the land ecological security index system, the evaluation index systems which have been commonly used also has some defects, and should be improved. Therefore, it is great significance to improve the those evaluation index systems to enable them to more scientific, more rational, and more comprehensive picture of the land ecological security. The different understanding of the land ecological security evaluation is the root cause of disunity of evaluation index systems. This paper argues that land ecological security evaluation refers to land ecological systems within a certain spatial and temporal scales, determine that whether its ecological structure and layout in a virtuous circle, and the ecological system can continue to meet the needs of human survival and development. According to the definition, evaluation is divided into two parts. So based on land use characteristics and socioeconomic conditions of the Wuxi, this paper constructs a land ecological security evaluation index system, which is adapted to the Wuxi. The main process in two steps:the first step is to start from the unifying concept of "pressure-state-response"(PSR) and the "natural-economic-social" evaluation index system framework to integrate them to form the first amendment framework of evaluation index system; the second step is based on the lack of analysis result on the first step, to introduce the landscape pattern indicators for the second amendment, and get a final evaluation index system framework. The evaluation index system framework is divided into five levels:The first level is the target, the ecological security of land; The second is the project level, divided into the overall correlation and spatial correlation; The third is the logical layer, including those pressure, state, response of the overall correlation and the spatial pattern of spatial correlation; The fourth is the system layer, describing the pressure, state, response of logic layer to all from the natural, social, economic three aspects, and the spatial pattern from stability of the landscape; The fifth is the index layer. Each step use the poor, average weight method, the composite index and other empirical research method to analyze the revised evaluation index system. The resulting new framework of the evaluation index system is to reflect a more complete assessment of the two content of land ecological security, and to reflect more fully the security situation in the land ecosystem.