基于改进DPSIR模型的京津冀地区优先回补地下水水源地筛选方法

Screening Method of Preferred Groundwater Recharge Source Fields in the Beijing-Tianjin-Hebei Region Based on Improved DPSIR Model

京津冀地区地下水水源地超采问题严重,引发了地下水水位持续下降等一系列问题,南水北调中线输水贯通为该地区地下水水源地的回补涵养提供了契机;然而,京津冀地区众多地下水水源地在回补条件和回补需求等方面各异,在有限回补水源条件下,亟需建立该地区地下水水源地回补优先性评价和分级方法,从而筛选出可优先回补的水源地.借助DPSIR(驱动力—压力—状态—影响—响应)评价模型理念,在综合分析地下水水源地产生资源环境问题的根本原因、存在压力、不利状态、对人类社会的影响以及地下水回补工程产生的响应基础上,解析影响地下水回补的关键因素,并以此为依据进行专家咨询和评分,建立了涵盖5个准则和21个指标的综合评价指标集.在阈值确定和数据标准化基础上,依据评分数据确定各准则和指标权重,最后通过综合指数法构建基于DPSIR模型的地下水水源地回补优先性评价体系,并对京津冀地区具有代表性的76个浅层地下水水源地进行了评价和分级.结果表明:以南水北调中线工程为轴,分布在山前冲洪积扇的32个浅层地下水水源地为优先和较优先回补等级,从山前至中部平原地下水水源地回补优先性逐渐变差;回补水源类型、浅层含水层储水空间、区域浅层地下水质量、浅层含水层防污性能是影响评价结果的最重要指标.研究显示,位于京津冀山前的冲洪积扇地区的地下水水源地应最优先考虑回补,中部平原地下水水源地大多为一般或暂不考虑,东部平原区地下水水源地普遍不适宜回补.该评价方法指标选取和权重计算科学客观,可为京津冀地下水水源地的涵养提供标靶和决策的理论支撑.

The over-exploitation of groundwater sources in the Beijing-Tianjin-Hebei Region has caused the serious problems,including continuous decline in groundwater levels.The completion of the mid-route South-to-North Water Transfer Project provides opportunities for the recharge and protection of groundwater sources in the region.However,the groundwater sources in the Beijing-Tianjin-Hebei Region vary in recharge conditions and needs.A comprehensive method for priority evaluation and classification of groundwater sources should be established to screen groundwater with high priority under limited conditions of water recharged.This study developed a comprehensive evaluation method based on the improved DPSIR(Drive-Pressure-State-Impact-Response)evaluation model.After analyzing causes of environmental and resource problems,existing pressures,adverse conditions,impact on human society,and the responses to groundwater recharge projects,this study explained the key factors of groundwater recharge,and sought opinions and collected scores from experts based on the explanations.An assemblage of evaluation indexes consisting of 21 indicators in 5 criteria layers was thus formed.The experts′scores-based weights of criteria and indicators were determined based on the determined threshold and data standardization.The priority evaluation system of groundwater recharge based on DPSIR through synthetical index method was formed,and 76 shallow groundwater sources in the Beijing-Tianjin-Hebei Region were evaluated and graded.The results show that 32 shallow groundwater sources distributed in the alluvial-pluvial fan regions on the axis of middle route of the South-to-North Water Transfer Project are ranked as‘high priority’and‘less priority’levels and the priority gradually decreases from the alluvial-pluvial fan to the central and coastal plain.The type and space of water recharge,regional groundwater quality and vulnerability are the most important indicators of the evaluation system.This study indicates that the water source of the alluvial-pluvial fan regions in the Beijing-Tianjin-Hebei Region is the top priority,the water source in the mid of the plain is of middle or low priorities,and ones in the eastern plain are not suitable for recharge.The selection of the system indicators and weight calculation are scientific and objective,providing an example and theoretical support for the recharge of groundwater source in the Beijing-Tianjin-Hebei Region.