Study On The Early-warning Of Land Ecological Security Of Guangdong Province

Land resources is the material base for human beings’ existence and developme-nt. After nearly half a century of development, with the development of economy, the advance of urbanization and industrialization, the rapid growth of population, the limited land resources has been unable to meet human beings’ demand. Large areas of farmland and forest land is converted into construction land, and seriously polluted, which is resulting in a series of ecological problems of land, and bringing in a serious impact on regions for sustainable development. Research on land ecological security has become an important part of research on the sustainable utilization for land resources, and which has great realistic significance.This paper takes Guangdong’s land ecological security as object of research, based on the P-S-R model, established a land ecological security warning index system of Guangdong Province from three aspects of pressure, state and response, and evaluated the land ecological security warning situation of Guangdong from two dimensions of time and space, which integrated by using the entropy method and comprehensive index method. On the basis of current warning situation evaluation, this paper predicted the tendency of land ecological security of Guangdong Province in 2013-2017 by using the method of radial basis function neural network model and Matlab9.0 software. Analyzing the main factors, which resulted in the variation of time and space of land ecological security, by the methods of entropy weight and coefficient of variation. According to the characteristics of major function regionalization of land ecological security, suggestions are put forward to improve land ecological security. Main Conclusions are summarized as follows:(1) The comprehensive land ecological security index showed an upward trend, the warning degree from the state of “moderate alarm” to “early warning” in 2000-2012, the comprehensive index rose only 0.107 between 13 years, land ecological system still face great difficulties. If there didn’t existed serious event, comprehensive land ecological security index would keep the same development trend that rose slightly in the stable, and would in the light alarm in 2013-2017.(2) On the basis of entropy weigh, results show that, the main factors that influenced the land ecological security of Guangdong are that the proportion of natural disaster-affected area, road density, the proportion of built-up urban area, Reserve land resources per capita, per capita GDP, economic density, per capita net income of farmers, proportion of GDP environmental protection investment, and the proportion of nature reserves.(3) The land ecological security index of 21 cities is various, which changes Within the range of 0.493~0.790. The spatial variation of eco-security showed that the warning degree was high in the northern and western area of Guangdong, the eastern area and Pearl River Delta were lower than the northern and western area, Zhuhai is the best, and Yunfu is the worst.(4) On the basis of coefficient of variation, results show that, the main factors that influenced regional difference of the land ecological security are that economic density, proportion of GDP environmental protection investment, the proportion of built-up urban area, population density, the proportion of natural disaster-affected area, the proportion of nature reserves and reserve land resources per capita. Economic factor is the main cause of land ecological security’s regional difference.(5) By overlaying the image of land ecological security of 21 cities in 2012 and of major function regionalization in Guangdong, analyzing the status and influencing index of land ecological security in every major function regionalization. The results show that the security level of optimizing development zone is best, key zones of development is second, the main grain producing areas is the worse. The degree of pressure-state-response is higher-low-higher in optimizing development zone, moderate-moderate-high in key zones of development, low-high-moderate in the main grain producing areas, high-higher-low in key ecological function areas. The influencing factors are different in different function regionalization.(6) According to the evaluation result, this paper improves land ecological security on account of major function regionalization. Optimizing development zone should put economical and intensive utilization of land in the first place. Key zones for development should focus on increasing the efficiency of land use. Key ecological function areas should adhere to the philosophy that the ecological priority and moderate development.