The spatially variable relative influences of climate and landscape on European streamflow behaviour

Understanding the complexity of hydrological systems is still a major challenge in the field of hydrology, despite advances in observations, large-sample datasets and analytical methods. Improving this understanding is important for addressing water-related challenges, including hydrological extremes such as floods and droughts.  

In this study we use more than 7000 catchments in Europe from the EStreams dataset (Nascimento et al., 2024) to identify hydrologically similar catchments and to assess their relative climate and landscape controls.  Across the wide spatial and temporal gradients of the study catchments, 10 hydrological response types (HRTs) could be identified using 40 hydrological streamflow signatures.  

The dominant controls of hydrological streamflow behaviour across the HRTs were identified using 84 climate- and landscape attributes with a Random Forest classification model. Climate emerges as the primary control of hydrological streamflow behaviour at the continental scale. However, in 4 out of 10 HRTs, landscape was found to be at least as strong, or even stronger, a control on the hydrological streamflow response. 

To further identify the climatic and landscape controls on a regional scale, the hydrological variability was analysed within the HRTs and across several major river basins by identifying subgroups within these hydrological and spatial groupings based on the 40 hydrological signatures. Using the same climate and landscape attributes, the drivers of hydrological streamflow behaviour were assessed for these subgroups. The results further support that climate and landscape jointly shape the hydrological streamflow behaviour.  

Overall, this analysis shows that European streamflow behaviour can be classified into a limited number of hydrological response types using streamflow signatures alone. While climate is the dominant control at the continental scale, landscape exerts considerable influence and often becomes equally strong or a stronger control at regional scales. These findings highlight the need to understand climate and landscape as joint drivers within a co-evolutionary perspective to advance our understanding of hydrological systems. 

The presentation will be based on Rudlang et al. (2025) as well as new analysis. 

References 

do Nascimento, T. V. M., Rudlang, J., Höge, M., van der Ent, R., Chappon, M., Seibert, J., Hrachowitz, M., & Fenicia, F. (2024). EStreams: An integrated dataset and catalogue of streamflow, hydro-climatic and landscape variables for Europe. Scientific Data, 11(1), 879. https://doi.org/10.1038/s41597-024-03706-1 

Rudlang, J. M., do Nascimento, T. V. M., van der Ent, R., Fenicia, F., and Hrachowitz, M.: Climate and landscape jointly control Europe's hydrology, EGUsphere [preprint], https://doi.org/10.5194/egusphere-2025-6372, 2025.