Relocation of Indonesia’s new capital, Nusantara, from Jakarta to Penajam Paser Utara is expected to drive rapid population growth, increasing potable water demand and urban expansion. This development, coupled with climate change, will exacerbate flood risks by intensifying surface runoff and will affect groundwater recharge. This study employs a GIS-based approach integrated with the Fuzzy Analytical Hierarchy Process (FAHP) to analyze groundwater potential zones (GWPZ) and flood hazard zones (FHZ) in Sanggai Watershed, under historical and future scenarios. In total, there are fourteen factors accounted for in this study: geomorphology, geology, drainage density, lineament density, rainfall, slope, elevation, TWI (topographic wetness index), TPI (topographic position index), curvature, distance from river, flow accumulation, soil type, and land cover. Results indicate that areas near Sepaku River show the highest groundwater potential, covering 19.4% of the study area under the SSP5-8.5 scenario with a projected 2055 land use and land cover (LULC) map. However, the same scenario projects a significant increase in high flood hazard zones from 9.5% under historical conditions to 16.9%. Amid the development process of Indonesia's new capital city, these findings provide valuable information for decision makers to produce policies related to sustainable water resources management, flood mitigation, and urban planning.
ADITYA et al. (Wed,) studied this question.