地表水资源的脆弱性及其评价初探

Concept and Quantitative Assessment of Vulnerability of Surface Water Resource

近年来国内水资源脆弱性研究存在理论探讨多于实践应用,北方地下水资源研究多于南方地表水资源研究以及水质脆弱性研究多于水量脆弱性研究的突出问题。本文以南方地表水资源系统为研究对象,在分析对比资源环境科学领域有关脆弱性研究相关成果的基础上,结合地表水资源系统的特点,提出了地表水资源脆弱性的概念,分析了地表水资源脆弱性的内涵和影响因素。认为地表水资源脆弱性包括水质和水量两个方面,从脆弱性构成因素上来看它们都可以分解为自然脆弱性、人为脆弱性和承载脆弱性。最后以衡阳盆地为研究区域构建了一个反映南方地表水资源系统自然脆弱性、人为脆弱性和承载脆弱性共12个指标的评价我国南方地区地表水资源在水量方面脆弱性的指标体系,运用综合指数法对衡阳盆地7个县(市)的地表水资源脆弱度进行计算,发现评价结果与实际比较吻合,说明评价指标体系和评价方法具有一定的可信度。

Vulnerability assessment of water resource system is very important for regional water management, water allocation and economic development. However, little attention has been paid to the surface water resource system in the South China, which is the primary water resource in this area. In this research, the Hengyang Basin is selected as the representative area of the South China based on some considerations such as data available, geographic characteristics, administrative boundaries and human activities. First, a concept of vulnerability of surface water system expressing the characteristics of surface water resource system in the South China is presented based on the resource and environment theory. The connotation and the contributing factors of the surface water vulnerability are analyzed subsequently. The vulnerability of surface water includes water quality and water quantity both of which contain natural vulnerability, artificial vulnerability, and burdening vulnerability. An assessment index system is established and applied to calculate the vulnerability degree, which is an indicator of water resource vulnerability during the exploitation and the utilization of regional water. Twelve assessment factors are selected based on the conditions of supply capacity, demand stress, and utilization efficiency of water subjected to the regional physical, economic, and water conservancy settings. These factors are integrated into the complex index model, which is capable and effective for the vulnerability assessment. And the vulnerability degrees of seven counties in the Hengyang Basin are calculated. The assessment results demonstrate the vulnerability of surface water in the Hengyang Basin is great and the regional distribution of the center and the north basin is greater than that of the south basin. Moreover, the assessment results are consistent with the practice, which indicates that the index system and the assessment method are credible. Therefore, enhancing the vegetation covering, strengthening the irrigation facilities, improving the water utilization efficiency, and adjusting the agricultural layout are important water management measures in the South China.