D1.1 User Requirement Document (URD)

This document summarises the user requirements for the European Space Agency Lakes Climate Change Initiative (CCI) project (Lakes_cci, http://cci.esa.int/lakes). This report synthesises information obtained through (1) review of existing reference documents and scientific literature, (2) CMUG Integration and Colocation meetings held in 2022 and 2023, and (3) interactions with the wider lakes research community. Results are also included from the third user requirements survey (https://climate.esa.int/en/projects/lakes/news-and-events/news/third-users-survey/) and from two dedicated user workshops, the Physical Processes in Natural Waters workshop held in Girona (1-5 July 2024) and the 7th LAKES Workshop on Parameterization of Lakes in Numerical Weather Prediction and Climate Modelling held in Milan (20-22 November 2024). Preliminary results of an additional survey related to the foreseen water transparency product foreseen are also presented.