MODELING OF GROUNDWATER LEVEL CHANGES DUE TO DEEP WELL EXTRACTION USING MODFLOW IN THE NORTH OF BANDAR LAMPUNG

Abstract

The growth rate of urban areas in the north of Bandar Lampung has caused the extraction of groundwater resources through deep well pumping to increase. Therefore, it is necessary to study the impact of pumping to prevent groundwater depletion. This study performs numerical simulation modeling to identify the impact of deep well pumping on changes in groundwater levels in three sub-districts north of Bandar Lampung city. Modeling is done using MODFLOW-6 and ModelMuse as a graphical user interface (GUI). The simulation method uses steady-state and transient models with four stress periods in 2000, 2010, 2020, and 2030. A total of 30 data wells are used for model setup, and 15 of them as observation and validation points. The simulation results show that hydraulic head changes occur at depths of 10 m to more than 40 m. Drawdown and groundwater head changes are concentrated at deep well points with a radius of up to 1 km. The model also successfully identified a decrease in groundwater level to more than 8 m in the deepest well area DW1. Thus, it is necessary to take action that can overcome the impact of changes in groundwater level due to pumping from deep wells. Furthermore, groundwater storage engineering can be one solution by utilizing rainwater harvesting technology to recharge the groundwater aquifer system.