Hydrologic response of springs to climate and rainfall variability to support smart and sustainable clean water infrastructure

Global climate variability poses a threat to water availability, but the understanding of local spring water responses to rainfall fluctuations remains limited. This study analyzed the influence of climate variability and rainfall on spring water discharge in Tlogorejo Village, Magelang Regency, over 31 days to support sustainable water management. Methods include baseflow separation (α = 0.95; BFI_max = 0.65), cross-correlation function, Brutsaert-Nieber recession analysis, and Mann-Kendall test. The results showed high resilience of the spring water system (discharge coefficient of variation 12.01%) and dominant baseflow (BFI = 0.92). The optimal lag time after rainfall was identified at 5-9 days (r = 0.267–0.291; p < 0.05). Brutsaert-Nieber recession parameters (a = 0.157; b = 1.20; R2 = 0.74) confirm laminar flow in karst-rift aquifers. The Mann-Kendall test revealed no significant trend in spring water discharge (Z = 0.925; p > 0.05), although rainfall exhibited a considerable trend (Z = 4.011; p < 0.05). These findings confirm the adaptive capacity of springs to short-term rainfall variability, with a critical period of 5-9 days as the basis for proactive management strategies, supporting the reliability of sustainable water resources.