The Effect of Depth-dependent Hydraulic Conductivity on Regional Groundwater Flow

摘要

Distribution of hydraulic conductivity is critical for modeling of regional groundwater flow.Unfortunately,few studies on regional groundwater flow have accounted for the gradual decrease in hydraulic conductivity with depth.Following Freeze and Witherspoon's (1967) study,the distribution of hydraulic head and resulted flow systems in a synthetic basin under a series of different rates of hydraulic conductivity which decreases with depth are obtained by using MODFLOW and PMPATH.It is found out that the development of flow systems varies greatly with decrease factor of hydraulic conductivity.With an increase in decrease factor of hydraulic conductivity,the penetration depth of local flow systems would increase.Furthermore,the decrease in hydraulic conductivity with depth would also have effect on the total recharge amount.Therefore,to analyze hydrologic problems which are related to regional groundwater flow,the gradual decrease in hydraulic conductivity with depth should not be neglected.