CLIMATE CHANGE IMPACTS ON GROUNDWATER IN THE KARST AREA OF BAUMATA, KUPANG

This study aims to analyze historical climate trends and project future climate conditions up to the year 2055, while also assessing the impacts on groundwater availability in the karst area of Baumata Village, Kupang Regency. Historical climate data (2004–2024) and projections (2051–2055) were obtained from the Regional Climate Model (RCM) simulations of the CORDEX SEA-22 domain. Variables analyzed included precipitation, minimum temperature, maximum temperature, and average temperature. Field measurements of spring discharge, bore wells, and dug wells were also conducted. Results indicate a sharp projected decline in annual precipitation from 1,877.9 mm to –1,042.6 mm (a decrease of –2,920.5 mm/year or –155.5%), with a downward trend of –74.9 mm/year (p = 0.096). Temperature variables showed minor and statistically insignificant changes. The total spring discharge reached 283.61 liters/second, with the largest discharge found at Baumata Spring (200 liters/second). The projected decline in precipitation may lead to reduced recharge of karst aquifers, threatening long-term groundwater sustainability. This study highlights the need for ecosystem-based water resource management in response to climate change in dryland areas.