Estimation of 3D hydraulic conductivity distribution of unconfined aquifer using the geostatistical method and its relation to water quality and flooding in Upper Citarum River

Abstract

The 3D distribution of hydraulic conductivity in the unconfined aquifer is needed to understand the interaction between groundwater and Citarum River, which may relate to water contamination and flooding. In this study, it was estimated using the geostatistical method. The data used are the hydraulic conductivity parameter from thirteen large-diameter dug wells determined using the slug test method. Further analysis was conducted using groundwater and Citarum River physical parameters, i.e. total dissolved solids, pH, and temperature. The results show that the hydraulic conductivity of the unconfined aquifer in the Upper Citarum River ranges from 8.34 x 10−7 to 2.19 x 10−5 m/s. The area with relatively high hydraulic conductivity, i.e. Ciparay and Solokan Jeruk Sub-districts, will have a greater possibility of groundwater or river water contamination depending on their interaction. Meanwhile, the area with relatively flat topography and low hydraulic conductivity, i.e. Majalaya and Baleendah Sub-districts, will be more susceptible to flood. Therefore, the mitigation of water contamination and flooding in the Upper Citarum River should consider the 3D hydraulic conductivity distribution, e.g. by monitoring the groundwater quality in some dug wells located in high hydraulic conductivity area and installing recharge or injection well to eliminate the artificial runoff.