The climate and the surface water in semi-arid and arid environments are characterized by extreme spatial and temporal variabilities, resulting in unpredictable patterns in soil moisture replenishment and groundwater recharge. This climate-driven variability together with local hydrogeological, geomorphological, and ecohydrological factors are directly influencing surface and ground water quality and quantity. Therefore, a good understanding of hydrological patterns in the semi-arid and arid environment, particularly those associated with droughts and floods, is critically important for delivering knowledge required for best practices in ecosystem and water management.

The session is particularly focused on the application of hydrochemical, physical and stable isotope tracers, but other relevant studies are also welcome. We especially encourage submissions contributing to understanding warm semi-arid and arid environments in the following topics:
• Ecohydrology: Plants – Surface water – Groundwater interactions
• Hydrochemical evolution of water and salinity development
• Soil water replenishment and unsaturated zone water budget
• Groundwater recharge and residence time
• Evaporative losses and surface water budgets
• Impacts of extreme events on hydrological and hydrogeological systems
• Oases and dryland hydrological interactions.