Urban Ecological Security Assessment Of Xiamen City Based On GIS

Along with the development of the city, the urban environment was destroyed, and appears "urban sickness" like crowded Population, housing shortage, traffic jam, environmental pollution, inhabitant quality of life and health standard reduction and so on. These urban ecological environment problems not only affect inhabitant's survival, but also seriously limit the development of the urban social economy. Being regarded as the center of local or national social economy development, the city is an ecosystem with highly intensively gathering population, and the city ecosystem security is more vulnerable. The city ecosystem is a complete artificial system, a primary area assembling the industries, the commercials, the production and the life activity of human society, and it forms enormous energy flow and information flow which is different from the farmland and the agricultural ecosystem. In the city ecosystem, the waste created in the production and the life, often need different decompositions and digestions. Various solid, liquid, gas wastes and etc. rejected and produced along the process of industrial production, have go far beyond the own natural purifying ability of the ecosystem, and threat both the city ecological and the environment. Therefore, the discussion on the city ecological security problems become especially important.In this paper, select the coastal city of Xiamen Special Economic Zone as the study area, with the support of GIS to study the ecological security city status of Xiamen City in 2007. Based on ecological security, ecology and the evaluation of relevant theory, and absorbed the related mature approaches of the regional ecological security assessment, the environmental assessment and the evaluation of land and natural resources. Trying to establish the theoretical framework of urban ecological security assessment as well as the indicator system, form the GIS database of ecological security comprehensive assessment, and evaluate the results of the indicators with visual expression. This article mainly includes five parts:The first part is to build the indicator system. Through the analysis of the influencing factors as well as consult the results of similar studies, according to the principle of indicator system building, this article designs a set of urban ecological security assessment indicator system model.The second part is to establish the indicator standards of urban ecological security assessment. Based on a great deal of information available and comprehensive analysis of various standards, establishes the standards of urban ecological security assessment.The third part is to determine the weights of evaluation indicators. This article chooses the method of principal component analysis, and calculates the weights of indicators with the help of the SPSS software.The fourth part is the comprehensive assessment of urban ecological security of Xiamen. Based on the data of 2007, analysis the indicators with spatial interpolation in GIS, and standardize indicators with the established standards, then calculate the complex index. According to the division level of ecological security, evaluate the ecological security status of Xiamen City.Part five is to propose management and adjustment methods of improving the urban ecological security. According to the research results, and combined with the concrete situation of the city of Xiamen, propose appropriate measures against the limiting factors.Characteristics and innovations:The merit of calculate the complex index of ecological security with grid units as the smallest units is: breaks the boundaries of administrative district, and reflects the status of ecological security spatial differences in a single administrative area.Perform the ecological security status of Xiamen City with the administrative boundary map and set the district as a unit for the statistical analysis. The conclusion is facilitated for government to compare and research, then establish the control measures of ecological protection and ecological action.Classify the urban eco-security grade based on the evaluated complex index, and statistics the final results in accordance with the level of security, it will give people a more intuitive impression of the current status of urban ecological security of Xiamen City.Based on the visualization of the ecological security, extend the research scale of urban ecological security to regional scale, so that we can indirectly know the ecological impact and the degree of constraints of the urban development on the surrounding areas.