基于GMS的地下水流数值模拟及参数敏感性分析

Numerical Simulation of Groundwater and Sensitivity Analysis of Parameters Based on GMS

为提高地下水流数值模拟的精度,减小因水文地质参数不确定性而产生的误差,需要对数值模拟模型的水文地质参数进行灵敏度分析。在对老莱河流域某灌区地下水流数值模型识别和验证的基础上,采用因子变换法对渗透系数、给水度、大气降水入渗补给系数值进行敏感性分析。结果表明,地下水位对含水层的渗透系数最敏感,其次是大气降水入渗补给系数,河谷地区因含水层岩性变异度较大导致地下水位对该区参数变化较敏感。通过参数敏感度分析能够筛选出数值模型中的不确定性因素,从而避免模型调参的盲目性,提高区域地下水资源评价的可靠性。

In order to improve the precision of the ground water mathematical model,and reduce the error which caused by hydrogeological parameter＇s uncertainty,we need to analyse the hydrogeological parameter＇s sensitivity of numerical simulation model.This paper based on the identification and verification of an irrigation district＇s groundwater flow numerical model,using factor transformation method to do the parameter analysis with permeability coefficient and specific yield of aquifer,atmospheric precipitation infiltration recharge coefficient.The results of the study show that,the ground water level is most sensitive to permeability coefficient,and then is the atmospheric precipitation infiltration recharge coefficient.For the large variability of aquifer lithology in valley area,the ground water level is more sensitive than any other regions.Through the parameter sensitivity analysis we can screen out the most uncertainty factors of the numerical model,thus to avoid the blindness of model parameters calibration,and improve the reliability of the regional groundwater resources evaluation.