Study On Evaluation Of Ecological Security In The Northern Farming-pastoral Transitional Zone

The fragile ecology and long-term human influences cause ecological and environment problems such as land desertification, grassland degradation, etc. in the Northern Farming-pastoral Transitional Zone, which impact local lives as well as economy, and threaten ecological security of areas around. However, there is still short of systematical studies on ecological security in this zone, and the evaluation of ecological security also needs to be strengthened.Based on analyzing eco-environment features of Northern Farming-pastoral Transitional Zone, joined with theory of regional ecological security, this paper has built the indicator system to measure the ecological security of the zone with both "Pressure-State-Response" model and Analytic Hierarchy Process, the evaluation model based on WAA operators, and taken Zhangbei county of Hebei province, a typical area, for example, measured its ecological security from 1999 to 2007, provided suggestions aiming to improve the situation of local ecological security from the idea, technique, and policy. The main conclusions are as follows:1. The main problems of the Northern Farming-pastoral Transitional Zone include:â‘ frequent natural disaster;â‘¡inconsistent economic construction, dense population, poor economic base;â‘¢aggravating eco-environment.2. The definition of Northern Farming-pastoral Transitional Zone ecological security is the state that the functions of the system, which is comprised of nature ecology, economy, and society, can satisfy the requests of human development and keep sustainable social development, even when the complex ecosystem access to outside pressure or damage.3. This paper has built an indicator system of ecological security evaluation of the Northern Farming-pastoral Transitional Zone with "Pressure -State -Response" model and method of Analytic Hierarchy Process. The measurement system composes of 4 levels and 40 indexes totally.4. This paper has taken Zhangbei County, conformed the comprehensive index weight by combining the subjective determination method-Analytic Hierarchy Process, with objective determination method-entropy method; and evaluated its ecological security using the model based on WAA operators. And the outcome has showed that the ecological security of Zhanbei County was not good from 1999 to 2007, but the integrative trend was up though fluctuated.5. According to the evaluation results of ecological security of Zhangbei County, this paper has suggested local ecological security should base on improving ecological environment, industry structure, and quality of population; take use of area advantages, increase the efficiency and stability, and realize the sustainable development of eco-environment, economy and society.