Test learners' ability to analyze how coupled hydrological processes, ecological interactions, and socio-economic drivers determine river basin resilience or lead to collapse under climate change and intensive water use. Scope includes conceptual coupled human–natural system frameworks, indicators and thresholds of resilience, feedbacks and tipping points, integrated modeling and scenario analysis, interpretation of hydrological and ecological data (e.g., streamflow, water quality, species responses) and socio-economic metrics (demand, governance, livelihoods), and evaluation of adaptation, allocation and management interventions under uncertainty.