为提高地下水溶质迁移模型的模拟精度，减小因水文地质参数不确定性产生的误差，需要对数值模型进行参数敏感性分析。以某冲洪积扇平原孔隙水为例，利用GMS7.0软件建立了地下水流模型和溶质迁移模型，并对模型进行了验证。通过引入敏感性指数作为量化指标，运用局部分析法中的因子变换法对模型中的渗透系数、孔隙度、弥散度三个参数进行了敏感性分析，参数变幅设置为20%。研究结果表明：（1）渗透系数和孔隙度的变化对污染物迁移距离影响最大，二者的敏感性指数相差20%；（2）弥散度的变化对污染物迁移距离的影响最小，与渗透系数和孔隙度相比，其敏感性指数相差一个数量级；（3）在20%的参数变幅内，污染物迁移距离与渗透系数和孔隙度呈良好的线性相关关系。

In order to improve the precision of groundwater solute transport model and reduce the errors caused by the uncertainties of hydrogeological parameters, sensitivity analysis of parameters is needed for the numerical model. In this paper, a groundwater flow and solute transport model was established to simulate the pore water in an alluvial fan plain using GMS 7.0, and the model was verified. Sensitivity index was introduced to quantify parameter sensitivity. Factor transformation method, known as a local analysis method, was used to perform sensitivity analysis of permeability coefficient, porosity, and dispersity. Variation range of the parameters was set to be 20%. The results showed that (1) permeability coefficient and porosity have the greatest impact on contaminant migration distance, and the difference of sensitivity index between the two parameters is about 20%; (2) dispersity has the least impact on contaminant migration distance, and the sensitivity index of dispersity is one order of magnitude lower than that of permeability coefficient and porosity; and (3) contaminant migration distance shows a good linear correlation with permeability coefficient and porosity within 20% of variation ranges of both parameters.

高等学校博士学科点专项科研基金（20130003120009）；国家国防科工局高放废物地质处置研究开发项目（科工计[2012]240号）