承压含水层特殊脆弱性评价中存在着诸多不确定性因素,影响评价结果的可靠性。本文分别运用局部灵敏度分析和Morris法的全局灵敏度分析对承压含水层特殊脆弱性评价模型中的参数进行灵敏度分析,为提高模型评价结果的可靠性奠定了基础。以济宁市承压含水层特殊脆弱性评价为例,对模型中各参数灵敏度进行分析。结果表明:弱透水层厚度、承压水与潜水水头差、弱透水层垂向渗透系数对承压含水层脆弱性评价模型的影响最为显著,弱透水层密度、分配系数与有效孔隙度对模型的影响次之,潜水含水层中污染物浓度与弱透水层弥散度对模型的影响最小;全局灵敏度分析结果显示,除弥散度外的各参数灵敏度系数的绝对值随着承压含水层脆弱等级的升高而降低。
Various uncertain factors in the specific vulnerability assessment of confined aquifer lower the reliability of assessment results.In a case study of Jining city,Shandong Province,this paper uses local sensitivity analysis and global sensitivity analysis of Morris screening method to analyze the sensitivity of eight parameters——(head difference between shallow and confined agquifers,pollutant concentration in shallow aquifer,partition coefficient and effective porosity,density,vertical permeability coefficient,thickness and dispersion of aquitard).The results show that the thickness of aquitard,the head difference between shallow and confined aquifers and the vertical permeability coefficient of aquitard are the most sensitive parameters,followed by density,partition coefficient and the effective porosity of aquitard.The aquitard dispersion and the pollutant concentration in shallow aquifer are the least sensitive parameters.In addition,the sensitivity of all the parameters except aquitard dispersion decreases with vulnerability degree.