西北内陆河流域生态安全评价研究——以黑河流域中游张掖地区为例

STUDY ON ASSESSMENT OF THE ECOLOGICAL SECURITY IN THE CONTINENTAL WATERSHEDS IN NORTHWEST China -A Case Study at the Middle Reaches of Heihe River Watershed, Zhangye Prefecture

从状态—压力—响应的角度设计了一种评价生态安全的指标体系 ,并以我国西北第二大内陆河黑河流域中游的张掖地区为例进行了实证分析。结果表明 ,张掖地区的生态安全呈现出不断改善的趋势。得到以下结论 :现代的生态安全问题不仅是自然界本身所具有的支撑能力大小 ,更重要的是生存在其中的人类对生态环境的建设和保护程度 ;为了给可持续发展提供生态安全保障 ,我们既要合理的利用自然界所提供的资源和服务 ,又应理所当然的对其进行补偿。

The study on the ecological security is an important issue in the study on the contemporary ecological economics and needs to pay a great attention to in the research domain of sustainable development. In this paper, it is considered that the ecological security is a status, which can provide an ecological guarantee for the security and sustainable development of the ecological economic system in a region, a country and even the world. Ecological security is characterized by foundation, entirety, regionalization, hierarchical difference, far reaching influence, etc., to the ecological economic system. An index system of assessing the ecological security is designed from the status-pressure-response conditions, and it is verified and analyzed by a case study at the middle reaches of Heihe River watershed, Zhangye Prefecture, Gansu Province, which is the second longest continental river in northwest China. In the calculation, the weights of the indexes are determined by the variant coefficient method. The results show that the ecological security in Zhangye Prefecture was in a trend of continuous improvement during the 7 years from 1993 to 1999, and the security index was increased from 0.4421 in 1993 to 0.6084 in 1999. However, the assessment of the ecological security status in the prefecture shows that the pressure to the local ecological environment was continuously increased in the 7 years (the status assessing value was decreased from 0.1882 in 1993 to 0.1586 in 1999).The assessment of the pressure to the ecological security shows that the practical (or potential) influence of the economic activities to the ecological security is firstly increased then decreased. The fluctuation of the response index reveals that the efforts of the local residents to protecting the ecological environment are not steady. Therefore, it is concluded that the modern ecological security is not only decided by the carrying capacity of the nature itself, but more importantly depends on the construction and protection degrees of the ecological environment. In order to ensure the ecological security for the sustainable development, the natural resources must be utilized rationally and compensated properly at the same time.