Global freshwater security is under unprecedented pressure as severe droughts and freshwater shortages intensify. Simultaneously, we are seeing rapid advancements in sensor technology and data science which are transforming how we map and quantify the complex processes in the human, ecological, and hydrologic systems within a watershed. Established satellite, airborne, and land- or water-based sensing technologies are being combined with new strategies for measurement and analysis. Innovations in sensor technology are providing new forms of measurement, enhancing data quality, reducing the costs for distributed sensing, and expanding access to measurements. We invite a wide range of contributions that leverage sensing technologies to push the boundaries of characterization and quantification, including but not limited to: 1) novel sensors, including lower-cost and DIY sensing, 2) data access, 3) multi-sensor fusion and data analysis, including AI and machine learning, 4) bridging scales and processes, and 5) real-time monitoring to support adaptive management strategies.

• H - Hydrology