承压含水层脆弱性影响因素分析及评价模型的构建——以山东省济宁市为例

Influencing Factors Analysis and Assessment Model of Confined Aquifer Vulnerability in Leakage Area: A Case Study of Jining,China

由于浅层地下水的污染以及承压水的开采,导致受到污染的浅层地下水越流补给深层承压水,增大了承压含水层受到污染的风险,如何评价承压含水层受到污染的可能性是迫切需要解决的问题。论文根据承压含水层受污染的特点将承压含水层脆弱性分为固有脆弱性和扰动脆弱性两个方面,同时根据脆弱性大小具有相对性这一特性,将研究区内承压含水层各脆弱性评价指标归一化,根据信息熵反映实测数据的效用值计算评价指标权重,而后加权求和得到反映脆弱性的综合指数,从而避免了构建脆弱性分级和定额的主观性。以济宁市承压含水层脆弱性评价为例,对评价方法的可靠性进行了分析,通过与数值模拟结果进行对比验证了方法的可靠性。该方法具有概念清晰、操作简便等特点,对无法建立地下水流数值模型和溶质运移模型的地区开展承压含水层脆弱性评价有一定的应用前景。

Because of the pollution of shallow groundwater, the deep groundwater exploitation is rapidly increasing, which strengthens the hydraulic connection between shallow groundwater and deep groundwater. Hence, it is very urgent to assess the risk of confined aquifer to contaminants. In this paper, the confined aquifer vulnerability to contaminants is separated into two parts： inher- ent vulnerability and disturbance vulnerability. According to the characteristics of aquifer vulnera- bility, a fuzzy comprehensive evaluation method is developed based on normalization of each eval- uation factor. The weights for evaluation factors in the model are obtained from the available value of data reflecting the information entropy. By this evaluation method the ranges and ratings of evaluation factors can be omitted, which partially avoid the subjectivity of evaluation results. This method is used to analyze the confined aquifer vulnerability of Jining city. The evaluation results are reasonably consistent with the numerical simulation. And this method is especially suitable for the area where the numerical simulation models of groundwater flow and solute transport can not be established.