The overarching objective of this CCN is to develop and demonstrate a prototype of Digital Twin Earth (DTE, see ANNEX 4 for the full list of acronyms) with focus on water cycle and hydrological processes and its impacts. In DTE Hydrology we aim to highlight the huge potential of high-resolution ESA satellite products for describing the water cycle, for predicting hydrology extremes (floods, landslides and drought) and for monitoring and managing water resources.