9.1 Process understanding through innovative sensors and remote sensing

9.2 Μodel hypothesis testing, diagnostics, and Causality

9.3 River systems in diverse climates and environments

9.4 Estimation and prediction under past and future conditions (climate, population, land use change)

9.5 Prediction in ungauged basins and prediction under uncertainty

9.6 Operational and impact-based forecasting, and data assimilation

9.7 Floods, Droughts and Water scarcity

9.8 Water and climate services - challenges and user-tailored developments

9.9 Water policy, Management and Society

9.10 Water, Energy and/or Food Nexus

9.11 Hydrological education and cooperative experiments (exchange programmes and virtual laboratories)