Trend analyses and characterization of discharge patterns of Austrian springs

Climate change alters the processes and components of the global water cycle. With about 50 % of the Austrian water supply depending on springs, the response of spring discharge to changes in climate is a key question of sustainable water resources management. The monitoring system of the Hydrographic Service of Austria provides long-term data of 94 springs distributed over whole Austria. With this study we provide trend analyses related to climate change and statistical analyses of spring discharge patterns related to their runoff characteristics on a national scale. The analyses account for the structure of the time series and address requirements of objectivity, transparency and reproducibility. Trend significance is assessed employing the seasonal Mann-Kendall test, and trend magnitude is calculated by the Theil-Sen slope. Autocorrelation function and pardè coefficient are calculated for each spring, similarities are explored using cluster analysis and set in a regional context. The results identify spatiotemporal patterns across Austria and highlight the significance of accurate spring flow characterization with regard to future challenges of water resources management.