Understanding hydrological processes in drylands, from hyperarid to semi-arid regions, is an urgent and evolving research frontier, particularly under the growing pressure of climate change, land use transformation, and increasing water scarcity. These regions, which span over 40% of the Earth’s land surface and support more than two billion people, face complex hydrological challenges due to their high climatic variability and limited water resources. This session welcomes contributions that advance our understanding of key hydrological processes in drylands (such as semi-arid zones in the Mediterranean or hyperarid ones in the Sahara and other desertic areas), including the spatial and temporal variability of rainfall, runoff generation mechanisms, soil moisture dynamics, and groundwater recharge. We particularly encourage studies that address the episodic nature of hydrological events, transmission losses, and the challenges of monitoring and modeling water fluxes in these environments. Contributions focusing on evapotranspiration partitioning, carbon assimilation, and the coupling of water and carbon cycles under changing climate and land cover conditions are also highly relevant. Given the scarcity of long-term, high-quality data in many dryland regions, notably in the Global South, we invite approaches that leverage remote sensing, citizen science, novel monitoring techniques, and integrative modeling frameworks. Finally, we seek studies that assess the impacts of climate change and support scenario-based planning for sustainable water resource management. By bringing together observational, experimental, and modeling perspectives, this session aims to foster interdisciplinary dialogue and identify pathways to improve hydrological understanding and resilience in dryland and semi-arid systems.
Akash Koppa