The Copernicus Emergency Management Service (CEMS) Hydrological Data Collection Centre (HDCC) is responsible for the collection, quality control, harmonisation and internal distribution of hydrological observations for the CEMS European Flood Awareness System (EFAS) and Global Flood Awareness System (GloFAS). 

Since 2012, CEMS HDCC collects near real time and historical hydrological observations of water level and discharge (sub-daily to daily frequency) from data providers across Europe. These hydrological observations are used mainly for the calibration of the hydrological model and for the real-time monitoring of the hydrological conditions across Europe (detailed information are available here). During 2022, the CEMS HDCC welcomed two new hydrological data providers: Confederación Hidrográfica del Segura (Spain), State Hydrometeorological Service of Moldova (Moldova). By the end of 2022, 49 data providers contributed with near-real time hydrological data at 2,382 stations across Europe, covering 33 countries and 54% of all the European water basins.

Starting from 2022, CEMS HDCC is responsible for the collection, quality control, and harmonization of daily historical discharge data for the global domain. These observations are used for the calibration and validatoin of the hydrological model (detailed information about hydrological data collection for the global domain are available here). 2,588 stations from 98 countries and 46 data providers were included in the CEMS HDCC database in 2022. 

The 2022 CEMS HDCC Annual Report presents the analysis of the hydrological data collected during the year 2022 across Europe, as well as an updated description of quality control protocols. Specifically, the analysis focuses on the 2,270 stations for which data delivery has been stable since January 2022. Of these, 460 offer exclusively water level data, 503 offer exclusively discharge data, and 1,307 stations provide data for both variables.

The report includes the following topics:

• data collection and data providers for the European and the global domain,

• protocol to quality check the hydrological data,

• protocol to quantity check hydrological time series, and gaps analysis for the European domain,

• hydrological conditions of the European domain,

• analysis of exceedance events for the the European domain.

Finally, the 2022 CEMS HDCC Annual Report report introduces the developments foreseen in 2023: the collection of reservoir data for the European extended domain, and the further extension of the collection of historical discharge data for the global domain.

The CEMS Flood team, and particularly CEMS HDCC, would like to thank the EFAS Partners and Data Providers that contributed to the CEMS hydrological data collection. We would like to acknowledge their dedication to EFAS, their commitment and the sharing of their hydrological data. We thank them for their cooperation with the CEMS HDCC, both in the provision of data and for their proactive role in responding to the questions and solving issues. Without their collaboration, the delivery of this report would not be possible.