The Deparment of Water Resources (WRS) of the Faculty of Geo-information Science and Earth Observation (ITC) is a multidisciplinary scientific department spacialising in scientific research and education in Earth Observation and geo-information sciences for the understanding, monitoring, predicting, and sustainable use and management of water resources. The presentation introduces observation models development by the Department, its long-term monitoring sites for satellite data product validation, and related computation infrastructure, including GeoNETCast and ILWIS toolboxes. It also provides a detailed description of the EcoExtreML project, which aims accelerating process understanding for ecosystem functioning under extreme climates with physics-aware machine learning. The project, which is a collaboration between ITC and eScience Center, targets to develop an efficient "digital twin" for soil-plant system.