Effect of Different Conduit-Network Recharge Ways on Karst Spring Simulation

Abstract

Two recharge ways, point inflow and lateral inflow, exist on the conduit network in karst aquifers. Point inflow is commonly included in pipe-flow models, but lateral inflow along the conduit network is often ignored. Few studies have paid attention to the potential influence of different recharge mechanisms on model simulation results. In this study, three models with different ways of recharging the conduit network were established based on a reservoir model and two analytical solutions. These models were applied to a karst spring to investigate the impact of different ways of recharge on simulation results. It is shown that the three models had very similar simulation results for both high and low flows after calibration. A series of synthetic experiments also indicated the model difference caused by the different ways of recharge of the conduit network could always be masked by the adjustment of other parameters in the model during the calibration process. These results imply that spring discharge as a model target alone may not help to identify the recharge way of the conduit network.