Hydrodiversity: A Concept to Understanding and Preserving River System Resilience

Hydrodiversity, an emerging scientific concept, represents the variability and diversity of water-related systems, processes, and resources. It encompasses hydrological features such as flow regimes, water levels, and groundwater interactions, and interacts dynamically with geo- and biodiversity. Despite its significance in maintaining ecosystem resilience, hydrodiversity remains underexplored, with no standardized definition or comprehensive framework for measurement.

In river systems, particularly in transition zones (riparian, littoral, and hyporheic areas), hydrodiversity plays a vital role in regulating connectivity, enhancing water and sediment transport, and supporting biodiversity. These zones act as ecological hotspots, influenced by seasonal hydrological processes like snowmelt-driven flooding and ice cover. However, climate change and anthropogenic pressures, such as land use changes and water management, threaten hydrodiversity, leading to ecosystem degradation and biodiversity loss.

Advancements in geospatial technologies, including multispectral lidar, unmanned surface vehicles, and hydrological modelling, provide new opportunities to quantify hydrodiversity. These tools enable precise mapping of water pathways, sediment transport, and habitat dynamics, offering insights into the interactions between geo-, bio-, and hydrodiversity. Coupled surface-groundwater models further enhance the understanding of hydrodiversity’s temporal and spatial variability.

We aim to establish a working definition of hydrodiversity and develop methodologies for its quantification. By leveraging cutting-edge technologies and interdisciplinary approaches, we seek to bridge knowledge gaps, support sustainable river management, and align with EU initiatives such as the Biodiversity Strategy for 2030 and the Nature Restoration Law.

Hydrodiversity research has the potential to transform our understanding of ecosystem processes, providing critical tools for predicting and mitigating the impacts of geomorphological changes in river systems. It highlights the importance of integrating geo-, bio-, and hydrodiversity for the preservation and restoration of river systems in a changing world.