Analysis of hydrogeological parameters and numerical modeling groundwater in a karst watershed, southwest China

A numerical groundwater model was developed on the basis of a conceptualized, equivalent, continuous medium for a karst basin located in Guizhou Province, southwest China. In this model, simulation of underground drainage and groundwater–river interactions were executed using the Drain and River packages of MODFLOW, respectively. Hydraulic conductivities were first determined using flow recession analysis methods proposed by Brutsaert and Lopez (Water Resour Res 34(2):233–240, 1998) and Mendoza et al. (J Hydrol 279:57–69, 2003). These parameters, together with recharge from precipitation, were further calibrated against observed water levels of subterranean rivers during 1988 and 1989 at three observation stations. The established model can be used to simulate temporal and spatial variations of groundwater levels and subterranean river discharges. The simulated results demonstrate that the total aquifer recharge comes mostly from precipitation and river leakage. Precipitation recharge and river leakage are about 70 and 13 % of the total aquifer recharge, respectively. Meanwhile, most discharge of the study watershed is from subterranean rivers. It accounts for 62 % of the total discharge and river drains only 8 % of the total discharge.