关中地区水土资源承载力复合指标体系及综合评价

摘要

针对现有一些承载力研究仅考虑水资源或土地资源的片面性和单一性问题,对指标体系进行完善,构建包括水资源、土地资源、科技功效、社会、经济及生态环境6个子系统共20个评价指标的水土资源复合承载系统的评价指标体系,采用改进模糊综合评价模型对关中地区水土资源承载力进行评价.在权重确定中,用基于模糊集决策理论的主观权重对熵权进行修正,提高了权重的可靠性.在改进模糊综合评价模型中,引入有效度指标,判断传统模糊综合评价结果的有效性,并对失效样本用基于贴近度的择近原则重新评价,提高了评价结果的可信度.评价结果表明:关中水土资源承载水平除咸阳为Ⅱ级,处于临近超载状态外,其他地市均在Ⅲ级左右,处于基本平衡状态.水土资源承载状态从优到劣依次为宝鸡、西安、铜川、渭南、咸阳.未来宝鸡、咸阳、渭南的水土资源承载力会有所提高,铜川则刚好相反,西安水土资源承载状态在2015年有所改善,但在2025年略微下降.%Most of current researches of soil-water resources carrying capacity (SWRCC) focus on single factor of either water resources or land resources and have been limited by their one-sidedness and singleness. This paper establishes a composite SWRCC index system which is composed of six sub-systems of water resources, land resources, technological efficacy, social, economic and ecological environment that contain 20 evaluation factors. The improved fuzzy comprehensive evaluation model is used for the evaluation of SWRCC in the study area. The subjective factor weights based on fuzzy set decision theory are given to modify the entropy weights of evaluation factors in the model to allocate the weights more reliably. The validity indexes are introduced to judge the effectiveness of assessment results obtained from o-riginal fuzzy comprehensive evaluation and failed samples are reevaluated using the selection nearness principle based on closeness degree to improve the credibility of comprehensive evaluation results. The results of research demonstrate that Xianyang has a SWRCC level of II close to being overload and other cities of Guanzhong area have the SWRCC level of Ⅲ indicating a basic balance. The SWRCC in the cities of Guanzhong area ranking from excellent to poor are Baoji, followed by Xi' an, Tongchuan, Weinan, Xianyang. The SWRCC of Baoji, Xianyang, Weinan will be improved in the coming years while Tongchuan has the opposite result. Meanwhile, SWRCC of Xi'an will increase in 2015, but has a slight decrease in 2025. The SWRCC indexes system in this study is feasible and reasonable, and the improved comprehensive evaluation results could truly reflect the situation of regional SWRCC in the study area.