绿洲生态环境质量评价指标体系研究--以张掖市绿洲为例

绿洲属于生态环境的极度脆弱区,同时绿洲生态系统又是一个复杂的系统,涉及自然与人文的诸多组元,因此定量评价其质量优劣状况具有重要意义也存在一定难度。在对我国西北内陆区域绿洲生态系统的性质和特点进行系统分析的基础上,根据整体性、实用性、稳定性、地域性、独立性原则,依据绿洲系统的压力-状态-响应模型,构建了适用于绿洲这一特殊景观类型的生态环境质量评价指标体系,并结合绿洲生态环境实际状况,应用层次分析法确定了各评价因子的权重和分级量化标准。在此基础上,以张掖市绿洲为例,对绿洲生态环境质量状况做了综合评价。

Study on the Index System for Evaluating the Ecological Environmental Quality in Oases--A Case Study in the Zhangye City Oasis

The ecological environment in oases is extremely vulnerable, and the oasis ecosystems are complicated and related to many natural and artificial factors. Therefore, it is of vital significance and there are some difficulties to quantitatively evaluate the ecological environment quality. In this paper, the index system for evaluating the ecological environment quality is developed based on analyzing the peculiar properties and features of the oasis ecosystems in northwest China according to the principles of the integration, practicability, stability, regionality and independence as well as the pressure status response model of the oasis system. Moreover, the weights and grading quantitative standards of all the evaluating factors are defined by using the hierarchical analysis based on the actuality of the ecological environment in the Zhangye City Oasis. On which the current ecological environment quality in the Zhangye City Oasis in Gansu Province, China, is evaluated. It is estimated that the synthetic index of the ecological environment in Zhangye City Oasis was 4.056 in 2000, which is quite close to the critical value. The pressure on the ecological environment in the Zhangye City Oasis will be undoubtedly increased with the population growth, more serious industrial pollution, irrational exploitation of natural resources, etc. Therefore, it is suggested to strictly control the population growth and water consumption, pay attention to the waster water reuse, optimize the rural economic structure, implement the project of withdrawing from farming to afforesting and grass planting, conserve the natural vegetation, develop the water saving agriculture, and improve the ecological environment.