| Ecological environment is a basic space for human subsistence and development. Its security is connected with the regional economy and social sustainable development. With the increment of population and development of economy, the pressure on environment becomes more and more heavier because of human disturbance, natural resources depletion. Environment pollution and ecological disaster have threaten the regional development, national security and social advancement. Therefore, the ecological security attracts more and more attention in the world. Ecological security, which is the important content of national security or regional security, has become a hot problem needed to be solved urgently in academic and practical levels.Hunan province is located in the middle of China at 108°47??114°13?E, 24°39??30°08?N. It is composed of 13 cities and 1 municipality, with a total area of 211 800 km2, 2.21% of total land area of China. The population was 67 321 000 in the end of 2005, which is about 5.18% of the whole population of China. Because Hunan Province is located in the middle reach of the Yangtze River, its ecological status is very important to keep an ecological balance of the water system, and to promote a healthy development of society and economy in the middle and lower reaches of the Yangtze River. While in the middle part of“three easily disaster-affected zones”of China, Hunan Province became one of the most severe disaster regions for its natural calamities. The special geographical location of Hunan Province leads to the sensitivity and fragility of its ecological environment. In recent years, the economy of Hunan province develops rapidly. However, with the appearance of frequent ecological disaster and serious environmental pollution, ecological security has become the restricted factors of sustainable development. At the same time, there are very few reports about Hunan province ecological security study. Therefore, it has important significance to analyze and research ecological security evaluation and controlling. The reasons are as follows: for one thing, choosing the tactics of ecological construction of Hunan province will be more accurate and scientific, for another the government can grasp the change of ecological security, then make controlling and administration measure in time. In addition, it is an effective strategy to provide practical instructions maintenances of ecosystem and sustainable development of regional economy, build ecological civilization. Theoretically it also expands the research realm of regional ecological security, especially by improving the methods of quantitative evaluation of ecological security.In this dissertation, the current situation of ecological environment of Hunan province was analyzed by collecting the statistic datum. The analysis included land use and degradation, vegetation situation and dynamic, water resource situation, ecological environment situation of wetland, biodiversity protection and environment pollution situation. Then, the main problems that impact the sustainable development of Hunan province were found out. Based on the preliminary analysis of current situation of ecological environment, we obtained the academic basis and background support to build the ecological security assessment system of Hunan province.With ecological footprint method, this dissertation made a time-sequence calculation of the ecological footprints of Hunan province from 1996 to 2004, incorporated the dynamic characteristics of the province's resources utilization into ecological footprint model, and based on these, analyzed the development trend of this region. The results showed that the ecological footprint per capita in the province increased from 1.2441hm2 to 1.6377 hm2, while the ecological capacity per capita decreased from 0.4819hm2 to 0.4556 hm2, with an increased ecological deficit year after year. At the same time, there existed a severe imbalance in the supply and demand of ecological footprint per capita. The contradiction between the ecological footprint and ecological capacity pricked up gradually, and the ecological environment was at risk during this time. By the regression model, the ecological footprint and ecological capacity of Hunan province were predicted in the following ten years. Results showed the ecological capitay presented downward trend, while the per capita ecological footprint and ecological deficit kept increasing, suggesting that the sustainable development and ecological security status of Hunan province in this time would be not optimistic. So improving the resource utilization efficiency and changing the economy structure depending on resources are urgent affairs to decrease the regional ecological deficit.It is of significance to study the effect of land use change on ecosystem service values. This dissertation aimed to provide decision support for sustainable use of resources and protection of eco-environment by assessing land use change and its consequent changes in ecosystem service values of Hunan Province. Based on dynamic data of land use in Hunan Province by RS and GIS, this dissertation analyzed changes in land use and ecosystem service value by using the evaluation model of ecosystem services which was put forward by Constanza, with referring to the table of Chinese land ecosystem service value of unit area. Results showed that from 1996 to 2004, the total ecosystem service values of the study area reduced dramatically from 32417.67×10~7 yuan to 31997.93×10~7 yuan in this period, and the areas of cultivated land, grassland, water bodies and unexploited land were decreased, while large numbers of constructed land were increased. Large amount of water bodies and cultivated land with higher ecological value coefficient transformed to constructed land with lower ecological value coefficient was the main cause of its decreasing. The decreasing tendence of regional ecosystem service values reflected the ecosystem service functions were lossed and weaken by the land use activities of human beings, which threaten the regional ecological security.Based on the analysis of regional eco-environment characteristics and the consideration of society and economy development, compared with the indicator systems of ecological environment assessment, the ecological security assessment index system of Hunan province was established by four big groups including natural situation, environmental pollution, disasters and social economy, total of 28 indicators after consulting some experts for advice of eco-environment and the assessing standard of ecological demonstration area of Hunan province. After ascertaining each assessment indicator, we adopted the method of Delphi and analytic hierarchy process to make sure the weight of the indicator system. Based on translating the experts' opinions into identification matrix, we calculated the weight of each indicator. Then we took a coincident test of identification matrix in order to make sure that the weight decided by each expert was effectual. In order to evaluate the hierarchy of ecological security degree, we classified the results into five levels, which included severe dangerous, dangerous, pre-alarm, sub-secure and secure respectively. By combining AHP and geographical information system (GIS) technology, taking the county as the evaluation unit, the synthetical assessment model of ecological security and the regional eco-environmental information system database were established. Moreover, supported by GIS the spatial pattern of the ecological security for this region was analyzed. The results of assessment showed that index of assessment for this region was symmetry, and the areas of the fifth (severe dangerous), the fourth(dangerous) and third grade(pre-alarm) regions were 64.8 percent of the total area in Hunan province, which indicated a inferior level of integral ecological security in this region. The ecological security of east was better than other areas, then south area's grade in the next place, and the west area and Dongting lake plain at the latest. The spatial pattern of ecological security degree in Hunan province was decreased from the east part to the west and westnorth. It was noticeable that the evaluation results of natural situation and social economy level in Dongting Lake area were good, while the synthetic score of ecological security was pre-alarm, and a few of dangerous or severe dangerous. The reason was that the deep effect of disaster and environmental pollution counteracted the advantages of natural environment and social economy. The characteristic of ecological security spatial pattern indicated that natural factors determined the trend of ecological security spatial pattern in Hunan province, however some other factors such as disasters, pollution and social economic were also affected the ecological security and its spatial pattern in some particular areas.Based on the analysis of the current situation of ecological environment, and the assessment of ecological security of Hunan province, this study presented the ecological function division of Hunan province by referring to the national technology rules. In this dissertation, Hunan province was divided into four ecological function parts and 11 sub-function parts, which consisting of Dongting lake plain and hilly region, East-center hilly and mountainous region, South mountainous and hilly region, Wuling and Xuefeng mountainous region. Based on the analysis of the ecological environment problem, combining with the assessment results of ecological security, some constructive countermeasures to protect eco-environment and improve development for each ecological function region specifically were put forward. |
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