Hydroclimatic extremes, including intense precipitation, flooding, and prolonged drought, are increasingly altering both water quantity and water quality across natural and urban systems. Such extremes influence runoff generation, streamflow variability, and the mobilization, transport, and transformation of contaminants, including nutrients, sediments, and contaminants of emerging concern (CECs). However, the interactions between hydrologic extremes and contaminant dynamics and their cascading impacts remain insufficiently understood, particularly under changing environmental conditions.

This session invites contributions that examine the coupled responses of water quantity and quality to extreme events across multiple scales, from watershed to riverine and urban systems. Studies using field observations, long-term monitoring datasets, process-based modeling (e.g., SWAT, SWMM), remote sensing, and data-driven approaches are welcome. Topics may include event-based pollutant loading, legacy contaminant mobilization, drought impacts, and the role of infrastructure and best management practices under extreme conditions. Studies that inform water resources planning and risk-informed decision-making are encouraged.

• A - Atmospheric Sciences
• B - Biogeosciences
• GC - Global Environmental Change
• NH - Natural Hazards