基于生态系统健康的生态承载力评价

Assessment of the ecological carrying capacity based on the ecosystem health

针对自然生态系统和传统生态承载力研究中评价标准相对单一、评价结果简化、不利于实际应用等问题,提出了基于生态系统健康的生态承载力概念,探讨了其内涵和基本特征;建立了水电梯级开发对生态承载力影响和基于生态系统健康的生态承载力计量模型;给出了基于生态系统健康的生态承载力评价指标体系和标准的确定方法,初步构建了基于生态系统健康的生态承载力理论框架.以黄河流域青海片为研究区域,建立了适合该区域的基于生态系统健康的生态承载力评价指标体系、权重和评价标准,并对青海片内水电梯级建设对生态承载力的影响进行了深入分析.结果表明,黄河流域青海片水电梯级开发规划实施的不同阶段对共和县生态承载力指数均为正面影响,但对青海片和沿黄其它县均为负面影响;梯级开发规划全面实施后,将使青海片的生态承载力指数下降9 9% ,生态系统健康等级也将由亚健康状态降至不健康状态.

An assessment of the ecological carrying capacity can provide an overall understanding of environmental impacts resulting from the continuous reservoirs construction. Therefore, studies on the theories and methods of the ecological carrying capacity assessment are significant for watershed or regional sustainable development. The concept of the ecological carrying capacity based on the ecosystem health is investigated to overcome the shortcomings of the traditional studies that were not convenient to use in practice due to their relatively simple assessment standards and conclusions. A corresponding conceptual model and computation model of the ecological carrying capacity are further proposed to analyze impacts of the continuous reservoirs construction. In addition, the establishing methods of the index system and the assessing standards for the ecological carrying capacity assessment are proposed. As an example, the ecological carrying capacity of Qinghai Province in the Yellow River Basin is researched. An index system, weights, and corresponding appraisal standards for the ecological carrying capacity are established for systematically analyzing the effects of the continuous hydroelectric power construction in this area. The results show that all ecological carrying capacity indices of Gonghe County keep increasing under different stages of watershed exploitation, whereas those of other counties have a tendency to decrease. With the overall enforcement of continuous reservoir construction planning, the ecological carrying capacity index of Qinghai Province will decrease 9.9%, and state of ecosystem will depress from sub-healthy level to un-healthy level.