Release of WMO report: State of Global Water Resources 2021

The World Meteorological Organization has published its first State of Global Water Resources report, providing insights into the availability of freshwater in different parts of the world and highlighting major flood and drought events.

In its first edition, the assessment is limited to streamflow, terrestrial water storage and the cryosphere, but it is intended to include groundwater, soil moisture and water quality in the future. The preparation of the 2021 report was largely based on simulated data from hydrological models and remote sensing information from satellite missions, which were compared and validated against observational data. Despite good correlation, the validation between modelled and observed results would benefit substantially from more hydrological information, as WMO Secretary-General Prof. Petteri Taalas pointed out, and he called on Member States to share more hydrological information in line with the WMO Unified Data Policy. Thereby he underlined the importance of the WMO Global Data Centres, whose contribution was also highlighted in the report. The report provides world leaders, decision-makers and citizens with information on the state of water resources for the first time and is an important step towards accurate water data and early warning systems in preparation for the United Nations 2023 Water Conference, COP28 and the 2030 Agenda for Sustainable Development.

The classification of hydrological basins for the global streamflow analysis of the assessment was based on the WMO Basins and Sub-Basins dataset of GRDC. In addition, observational river discharge data from GRDC were used for the validation of simulated river discharge data from Global Hydrological Modelling Systems. The head of GRDC, Ulrich Looser, was also involved in the preparation and review of the assessment report.

For more information see WMO Press Release and the Report plus Annex.