重点地区地下水脆弱性评价研究——以北京市某大型水厂水源地为例

Groundwater Vulnerability Assessment in Key Areas——Take Water Source of ALarge Water Plant in Beijing as An Example

地下水在北京多元供水格局中占据着重要地位,对地下水水源地脆弱性评价可为地下水保护、开发利用提供科学依据。根据DRASTIC模型,基于研究区地质条件,综合考虑污染物迁移转化特性、地下水补径排特征等因素,选取地下水位埋深、含水层净补给等7项指标,定量评价了研究区地下水脆弱性。结果表明,研究区地下水脆弱性均在“中等”以上,并以高脆弱为主,高脆弱区面积占总面积的一半以上(56.1%),脆弱性总体呈现中部重、东西部轻的特征。导致研究区脆弱性级别较高的主要因素是含水层净补给量、含水层介质、包气带介质和渗透系数。

Groundwater plays an important role in multiple water supply pattern of Beijing.The assessment of the vulnerability of groundwater source provides scientific basis for groundwater protection,development and utilization.Based on DRASTIC model and the geological conditions of the study area,and taking into account the characteristics of pollutant migration and transformation,groundwater recharge and discharge,seven indexes are considered,which includes the depth of groundwater level and net recharge of aquifer,quantitatively assessing the vulnerability of groundwater in the study area.The assessment result shows that the vulnerability of groundwater is above“medium”level,and the ratio of“high”level is more than half(56.1%).The overall vulnerability is severe in the middle and slight in the east and west.The main causes of high vulnerability level are net aquifer recharge,aquifer medium,vade-zone medium and permeability coefficient.