Hydrometric and isotopic event SIGNatures to evaluate functional resilience of diverse hydrological Systems to global change (HydroSIGNS)

• Applicants: Professor Dr. Andreas Hartmann; Dr. Larisa Tarasova
• Subject Area: Hydrogeology, Hydrology, Limnology, Urban Water Management, Water Chemistry, Integrated Water Resources Management
• Term: since 2025
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 564932275

Advancing global climate and land use change particularly threatens vulnerable hydrological systems with low functional resilience. Such resilience is defined by two components: the ability of systems to withstand change and to buffer extremes. However, it is still unclear where the global hotspots of low and high functional resilience are located. Isotopic signatures that reflect the origins and residence times of water in springs and streams is the most reliable indicator for detecting such hotspots. However, the required stable water isotope measurements are still scarce globally, especially for springs that are particularly susceptible to global change. Instead, hydrometric event-based signatures can be obtained from streamflow and precipitation time series available for many locations worldwide. However, it is still unclear where and when, i.e., in which types of hydrological systems, and under which event conditions the isotopic signatures can be inferred from hydrometric signatures and which hydrometric signatures are the most suitable for such inference. The aim of the project is to quantify functional resilience (i.e., the ability to withstand change and buffer hydroclimatic and environmental extremes) of hydrological systems across spatial scales worldwide by means of hydrometric event signatures most closely capturing water origins. As part of the project, we will derive hydrometric event-based signatures for a wide set of global river catchments and karstic springs, which are known for their quick reactions on climatic changes and extremes. These signatures will be rigorously tested and improved using the collated datasets of stable water isotopes and the results of own isotope measurements that will be conducted as part of the project. Once tested, these signatures will be used to perform the analysis of functional resilience of hydrological systems along the subsurface heterogeneity gradient (e.g., from very heterogeneous systems, like springsheds of karstic springs, to small watersheds with heterogeneous subsurface structure and to larger river catchments), which might be associated with contrasting levels of vulnerability. The ultimate objective of this project is to develop a novel process-based model-independent method for evaluating sensitivity of hydrological systems to global change and exacerbating extremes applicable at the global scale. This will help to identify regions where hydrological systems might fail to provide ecosystem and societal services in the future and support development of target adaptation measures for such regions. Moreover, this project will help to bridge the gap between large sample hydrology and critical zone communities and to obtain reliable process-based insights on functional resilience of different hydrological systems to the ongoing global change worldwide.

• DFG Programme: Research Grants
• International Connection: Austria, Canada, Switzerland, United Kingdom
• Cooperation Partners: Professorin Dr. Gemma Coxon; Dr. Thomas Dirnböck; Professorin Dr. Hongli Liu; Dr. Ilja van Meerveld, Ph.D.; Dr. Ross A. Woods
• Co-Investigator: Dr. Shijie Jiang