Research Of The County Land-Use Change And Evaluation Of Ecological Safety

In recent years, global environmental problems have become increasingly significant, such as the greenhouse effect, acid rain, ozone depletion and the change of global climate. This have been resulted in severely damage of ecological system, and triggered a series of global crises, ecological security has become one of the 21st century's challenges, and important component of national security and regional security. Ecological security can affected by natural factors (such as global climate change, earthquakes, volcanic eruptions, etc.) and human activity (industrialization, urbanization, land use/cover change, etc.), or by combined effect of this two factors. In the environmental problems which were caused by human activities, the process of land use change plays a decisive role on regional ecological security. Therefore, integrate the research of the two hot spots, and study a certain area's land use change and ecological security, is conducive to understand this area's land use and ecological security, and propose the specific measures of building ecological security of land resource, all of these have important practical significance for the formulation of land use planning which can guarantee ecological safety and ensuring the regional economic, social and environmental's sustainable development.This thesis selected regions of Rongchang county of Chongqing, and researched its land-use change and ecological security, this is benefit to fully understand the land resources' quantity and quality of Rongchang, and thus propose measures for protection and regulation of the land resources and ecological security specifically.This paper consist of 6 chapters, in the literature review section, introduced the concept of ecological security of land resources, summarized the research, evaluation methods, and discussed the problems of ecological security research and developmental direction; in the preface, introduced the content and technical line; chapter 3 described the overview of Rongchang county, research methods and so on; chapter 4 presented the main reasons of land use change based on the analysis of dynamic changes; chapter 5 using Composite Index Model, built assessment index system of land ecological security, and used AHP to determine the weight of each index, used safety index method to dimensionless, analyses the ecological security between the year of 2003 and 2008 by time series analysis; Chapter 6 proposed the environmental management measures to improve the ecological security of land resources of Rongchang county, hoping to provide basis for Rongchang's land use planning. This paper came to the following main conclusions:1. From the structure of land use, quantity, amplitude and speed etc, to analysis the land use change of Rongchang between the year of 2003 and 2008. The results showed that:(1) From the year of 2003 to 2008, dramatic dynamic changes of agricultural land are mainly garden, woodland and farmland, the garden area increased 1,310.13 ha, the rate of type change of land use is 38.43%, the dynamic degree of change is 7.69%; the woodland reduced 453.38 ha, the rate of type change of land use is 4.30%, the dynamic degree of change is 0.86%; the cultivated land decreased 1232.65 ha, the rate of type change is 2.14%, the dynamic degree of change is 0.43%.(2) 2003 to 2008, dramatic dynamic changes of construction land type are land for towns, water conservancy facilities, rural settlements, towns land increased 832.55 ha, the rate of type change of land use is 108.84%, the dynamic degree of change is 21.77%; land for water conservancy facilities increased 43.35 ha, the rate of type change of land use is 3.61%, the dynamic degree of change is 0.72%; the rural 'residential land increased 450.1 acres, the rate of type change of land use is 0.31%, the dynamic degree of change is 0.06%. In addition, the change rate of transport land is also obviously.(3) From the whole,2003-2008, agricultural land and unused land area in Rongchang County continued to decline, agricultural area reduced 855.51 ha, unused land decreased 103.77 ha; at the same time, the construction land increased 959.28 ha.2.2003-2008, ecological security of land value of Rongchang County was lower than 0.5, the land of ecological environment are still in the "dangerous" state. The further analysis found that, the overall value of land resources ecological security was being increased in the past 5 years, and it shows that the ecological security situation are gradually improved. The value of land ecological security changed slowly, mainly due to the rapid economic development of Rongchang demand more land resources in recent years, especially construction land. Agricultural land decreased rapidly, while the Rongchang County paid more attention to economic development, belittled the ecological environment construction and protection, the ratio of the environmental governance input costs less than 1% of GDP, the pollutants reduction mainly by natural ecological environment's digestive and absorption. Therefore, the value of land ecological security has increased, but changed slightly.