干旱区地下水功能评价与区划体系指标权重解析

Index weight analysis of groundwater function evaluation and zoning system in arid areas

针对西北内陆平原区自然湿地和天然植被对地下水埋藏状况具有强烈依赖性的特点,遵循多目标组合、属性归类、功能聚合和系统唯一的层次逻辑,构建了适合干旱区地下水功能评价与区划体系,与2006版相比,赋予了该体系指标不同的内涵;在由2006年版的22项要素指标精简为14项的同时,增设了“自然湿地景观维持性”属性指标和“湿地环境与地下水关联度”、“绿洲覆盖与地下水关联度”及“土地荒漠化与地下水关联度”等要素指标;按照关键性、关联性和系统性解析权重原则,分解了体系中要素指标层14项要素指标的权重;基于地下水的资源占有性、资源更新性、资源可用性和地下水生态功能属性指标,诠释和解析了干旱区地下水资源功能和生态功能的权重,使之更符合西北内陆地区地下水功能的自然属性状况。在石羊河流域评价结果表明,该体系具备支撑干旱区地下水合理开发与生态保护针对性管控的作用。

The most striking characteristic of an arid climate is a lack of moisture with the low precipitation,while strong evaporation,particularly in northwest China.In the natural lake wetland,the growth state of natural vegetation and the quality of basic farmland are strongly dependent on the groundwater burial condition.Therefore,this study aims to propose a set of groundwater function evaluation and zoning,to establish a novel evaluation system for the groundwater function in arid area.4 layers were divided,including from high to low(marked as the system target layer),criterion function layer,attribute index layer,and factor index layer.Specifically,14 indicators were set in the evaluation system.A step to build the system was as follows:To combine the logic and multi-objective indicators,attributes classification,function aggregation,and unique system,called“dry area system”for short.The requirement and standard for the evaluation of the groundwater condition were generally associated with“Technical requirements for evaluation and zoning of groundwater functional zones”released by China Geological Survey Bureau in 2006,where the indicators are guiding the evaluation and division of groundwater function in North China,northeast China,Shanxi great Basin and northwest China.Compared with the previous edition,the“dry area system”mainly expressed the indexes of“Arid area system”,representing the essential characteristics of groundwater in northwest China,further to pose the new connotation on the attribute indexes of a system,with the removal the number of less common indexes.Specifically,22 indicators were reduced to 14 factors,with the addition of some new indexes,including the attribute index of“natural wetland landscape maintenance”,the factor indexes of“wetland environment and groundwater correlation”,“oasis coverage and groundwater correlation”,and“desertification and groundwater correlation”.In this study,an index weight method of“Arid area system”was proposed using the sequence synthesis mathematical theory,and the analytic hierarchy process as the theoretical framework.The original data was selected to serve as the basis of weight evaluation,according to the principle of index weight analysis,including the critical,correlation,systematic evaluation.The index weights of 14 factors were then analyzed in factor index layer.Based on the indexes of possession,renewal,availability,and ecological function of groundwater resources,the weight of groundwater resources function and ecological function in arid area was elucidated to fit in the northwest inland groundwater function of the natural properties.The application in Shiyang River Basin showed that the“Arid area system”was feasible for the groundwater function evaluation in arid area.The evaluation data was also suitable for the essential characteristics of groundwater resources and ecological function in different areas.The finding can provide a sound theoretical basis for fine management groundwater and ecological protection,and thereby to support rational development of groundwater and targeted management of ecological protection in arid areas.