20.500.12556/ReVIS-13349 Young water fractions in spring discharge Transit time distributions are fundamental to hydrologic research and practice, providing insights into how catch ments store, transport, and release water and solutes. Mean transit time estimates, however, often suffer from significant aggregation errors in heterogeneous and nonstationary catchments. The young water fraction (Fyw) provides a robust alternative that directly reflects the proportion of recent precipitation in discharge and enables consistent comparison between catchments. While numerous studies have focused on estimating Fyw in rivers, little is known about its magnitude and variability in springs. To address this knowledge gap, this study quanti f ies Fyw in spring discharge from a diverse set of 469 springs in Austria. Across the dataset, Fyw is generally low and approximately log-normally distributed (mean 0.06), with variability among springs largely controlled by aquifer structure: karst springs display the highest fractions and greatest variability, talus springs intermediate values, and fracture and alluvial springs low fractions with limited variability. Evaluating the sensitivity of Fyw to discharge reveals distinct responses to hydrologic forcing: karst springs are most sensitive, reflecting tempo rary shifts in relative flow path contributions, whereas fracture springs are least sensitive, reflecting conservative f low dynamics. Drawing on a dataset of 565 rivers compiled for comparison, springs exhibit substantially lower Fyw, likely reflecting their predominantly slow subsurface flow paths. By analyzing Fyw across a large number of springs, this study delivers the first systematic insight into young water contributions to spring discharge, informing conceptual models, water resource management strategies, and contamination risk assessments. young water fraction stable isotopes spring discharge transit time alpine hydrology comparative hydrology frakcija mlade vode stabilni izotopi izvirni pretok čas prehoda alpska hidrologija primerjalna hidrologija true false true Angleški jezik Slovenski jezik Neznano 2026-03-23 09:56:45 2026-03-23 09:56:45 2026-03-24 03:07:02 0000-00-00 00:00:00 2026 0 0 Nasl. z nasl. zaslona; Opis vira z dne 23. 3. 2026; 15 str. [article no.] ǂ135221 Vol. 670 May 2026 0000-00-00 NiDoloceno NiDoloceno NiDoloceno 0000-00-00 0000-00-00 2026-05-01 556.36 1879-2707 272580355 10.1016/j.jhydrol.2026.135221 https://www.sciencedirect.com/science/article/pii/S0022169426003185?via%3Dihub 1 38c86729-2696-11f1-aa40-001a4af901a5 https://revis.openscience.si/Dokument.php?lang=slv&id=15890 1-s2.0-S0022169426003185-mmc1.pdf 1-s2.0-S0022169426003185-mmc1.pdf 1 6D0B4EAE439112C276838282C6FB2750 4157a2c1814397b4d699bd31f0ce82c6a2551b467af68309f178fc4743abd132 6617a9cc-2696-11f1-aa40-001a4af901a5 https://revis.openscience.si/Dokument.php?lang=slv&id=15892 Univerza Alma Mater Europaea 0 0 0