Identification of Groundwater Potential Using Wenner Configuration 2D Resistivity Method (Kupang, Nusa Tenggara Timur)

Kupang is the capital of the Indonesian province of Nusa Tenggara Timur, and has an estimated population in 2019 of 434,972. It is the biggest city and port on the island of Timor. The needs for groundwater is urgent in Kupang. The geology of Kupang is located on the Batu Gamping Koral Formation which composed by coral limestone, which is physically barren and dry. So that local residents often have some problems with water availability. Therefore, needed the information about potential and depth of groundwater aquifers in the area. Measurement of the Wenner configuration 2D resistivity method has been carried out to identify the subsurface to determine the potential for groundwater. Inversion were performed using the method of Least-Square Smoothness Constraint. The result of the interpretation shows that the subsurface resistivity value in the area ranges from 0.4-13.108 Ω m, and groundwater aquifer potential lies at trajectories KPG 01, 02, 03, 04, 14, 15. In the Batu Gamping Koral Formation there is groundwater potential in depth between 0-85 m with a resistivity value of 25.6-205 Ω m, and its constituent rocks are limestone sand and sand. In the Alluvium Formation, the groundwater potential in depth between 0-20 m with resistivity value of 25.6-410 Ω m, and its constituent rock is sand. Whereas in Bobonoro Formation, there is no groundwater potential.