Study On Early-Warning Of Land Ecological Security In Nanning City

For human, Land is the foundation to exist and develop and safety is one of the basic needs. Land ecological security, which is the key point and foundation of sustainable utilization of land resources, has great influence on the sustainable and stable development of society. As the capital of Guangxi, Nanning is one of the most important cities in western regions. Recent years, with the changes of internal and external environment, the regional backwardness advantages gradually appear, the economy develops rapidly, the changes of land utilization have more and more disturbance on land ecosystem and the land ecological security is not optimistic. Under this background, it has practical significance and application value to make warning research on land ecological security in Nanning.Based on the relative data, the author firstly uses theories and methods of warning research to make a qualitative analysis on the main problems of land ecosystem, secondly, the warning index system of Nanning land ecosystem has been built by Analytical Method object properties. Thirdly, using the mathematical method, the author predicts the development trend of warning index by which the author can evaluate the condition of Nanning land ecosystem and forecast the time and place that the dangers will appear, as well as its damage. Finally, by making the simulated regulation on the land ecosystem security in Nanning, the author points out the key factors influencing the regional land ecosystem security and puts forward some effective measures. Based on the above research, the author makes the following conclusions.(1) During period from 2000-2009 in Nanning City, the comprehensive warning index of land ecological security increases slowly, which is generally in severe warning condition. Due to the decreasing of comprehensive warning index of land social ecological security, the coordinate index of regional land ecological security decreases which generally fluctuates between the coordination and the incoordination. It's impossible to forecast that the situation of regional land ecological security will improve whose speed will slow down year by year, and the index will be still in warning condition after 2010, for that the bottleneck effect of the low level of the land social ecological security will appear. (2) Through simulated regulation on the total system of land ecological security and the factors with different attributes in Nanning, the author makes the conclusions that:the synchrinous positive changes of land natural, economic and social system have great influence on the improvement of regional land ecological security; the simulated regulation basing on sensibility greatly influences the increasing of the regional warning index and has few influence on the increasing of the coordinate index; the simulated regulation basing on controllability has great influence on the comprehensive warning index and the coordinate index; the simulated regulation basing on the security degree has great influence on the improvement of the coordinate index and has few influence on the improvement of the comprehensive warning index of regional land ecological security.(3) If relevant departments pay attention to this question, take effective measures and complete the setting regulation target, the condition of regional land ecological security will greatly improve before 2014:comparing to 2009, the comprehensinve warnning index of land ecological security, natural subsystem, social subsystem and economic subsystem will correspondingly increase by 0.169,0.026,0.087 and 0.056; the grade of warning condition will turn from the moderate warning condition to light warning condition; the coordinate index of land ecological security will increase to 0.698 and the degree of coordination will obviously increase.Taking the reality of Nanning in the next 5 years into account, the author puts forward 7 measures to eliminate the warning condition of regional land ecological security:improve the forest coverage and protect the species diversity; strengthen protection of cultivated land and relieve the stress of cultivated land; control soil pollution and improve the agricultural ecosystem; improve the intensive utilization of land; increase the investment of environmental construction and reduce the environmental pollution; perfect the spatial arrangement of city and reasonablly propel the urbanization; balance the urban and rural development and promote the social equity.