水资源承载力理论基础探析:定义内涵与科学问题

Study on theoretical analysis of water resources carrying capacity:Definition and scientific topics

水资源承载力是评判水资源与经济社会及生态环境之间是否协同发展的一项综合指标,研究水资源承载力对实现人水和谐具有重要的意义。在综述水资源承载力研究进展基础上,以现阶段人类活动对水资源要素利用和水资源系统扰动的主要方式为出发点,从水量、水质、水域空间和水流状态4个维度赋予了水资源承载力新的内涵,并基于新内涵构建了水资源承载力评价指标体系。认为在水量上应以保障生态用水为前提,确定地表水可利用量和地下水可开采量阈值;在水质上应满足水功能区划水质目标及生物多样性的需求,确定保障鱼类等正常生长的浓度阈值;在水域空间上应统筹考虑防洪、生态、景观等需求,确定不同降水条件下的适宜水域面积阈值;在水流状态上应侧重水系连通对水生态的影响,确定不同水系连通指标的阈值。最后,指出水资源承载力"量-质-域-流"四维演变机制、"水资源-经济社会-生态环境"系统的承载弹性阈值、经济社会发展与生态环境保护之间的"平衡点"以及水资源承载力调控机制是水资源承载力研究的四大关键科学问题。

Water resources carrying capacity （WRCC） is a comprehensive index to evaluate the coordinated development of water resources, economic society and ecological environment, thus, it is significant to study WRCC to realize the harmony of water and human beings. Based on the research progress of WRCC, and take the main interference and influence of human activities on water system as a starting point, a new meaning of WRCC is defined from water quantity, water quality, water space and streamflow, and the evaluation index system of WRCC is constructed. The surface water resources availability and groundwater should be determined on the prerequisite of ensuring ecological water use; water quality should meet the water function regionalization target and the demand of the biodiversity to determine the concentration that ensure the normal growth of fish; it is necessary to take into account flood control, ecology, landscape and other requirements in the water space, and determine the appropriate water space area under different precipitation conditions; it should focus on the impact of connected water system on water ecosystem in streamflow, and the threshold of different water system connecting index should be obtained. It is consid- ered that evolution mechanism of WRCC ＂quantity - quality - domain - flow＂, the elastic threshold of ＂water resources-economic and social-ecological environment＂ systems, the balance point between socio-eco- nomic development and ecological environment protection, and regulation mechanism of WRCC are four key scientific topics in this research field.