Modelling the Future: Groundwater Responses to Climate Change in Talomo-Lipadas Watershed, Davao City, Philippines

This research investigates the long-term impact of climate change on groundwater recharge (seepage) within the Talomo-Lipadas Watershed, Davao City, Philippines, over the next eighty-nine (89) years. Employing the Statistical Downscaling Method (SDSM), stationscale climate scenarios were generated for three future time slices centered on 2020 (2011-20140), 2050 (2041-2070), and 2080 (2071-2100). These scenarios, indicating a projected increase in temperature within the watershed, were then used as input for the BROOK90 hydrological model to simulate groundwater recharge. The modelling results project a decline in groundwater supply from 109.01 million cubic meters (MCM) in 2020 to 103.53 MCM in 2050 and further down to 99.81 MCM by 2080. This projected decrease in groundwater recharge has significant implications beyond just water availability. Reduced groundwater flow can impact baseflow in rivers, affecting aquatic ecosystems and potentially exacerbating water scarcity during dry periods. Decreased recharge also has implications for other water-related sectors, including agriculture (irrigation), industry (water supply), and domestic water use, potentially leading to increased competition for dwindling resources. These findings underscore the urgent need for adaptation strategies to mitigate the effects of climate change on groundwater recharge within the Talomo-Lipadas Watershed. Further research employing diverse hydrological models is recommended to validate these findings and provide a more robust basis for developing sustainable water management plans.