Introducing EU-Hydro 2.0: A Copernicus high-resolutionhydrographic product across Europe based on latest generationelevation and ancillary data

The EU-Hydro dataset offers detailed information on the geographical distribution and spatial characteristics of water resources throughout Europe, such as river networks, surface water bodies and watersheds. It is a hydrographic reference dataset part of the Copernicus Land Monitoring Service (CLMS) portfolio, implemented by the European Environment Agency (EEA). The first version of EU-Hydro was developed in 2012, with subsequent updates aimed at improving data accuracy and network topology. EU-Hydro has been widely used for hydrographic mapping applications, among them serving as input to several CLMS productions. However, its use for hydrological modelling remained limited due to inconsistencies and shortcomings in data structure, resolution, and quality. To offer a state-of-the-art next generation of EU-Hydro, it is currently being updated to produce an improved and upgraded version of this unique European reference dataset. Highlighting the importance of water mapping and modelling, the new version of EU-Hydro (EU-Hydro 2.0) shall tackle the requirements of a modern reference product within the pan-European hydrological domain, serving various use cases, including hydrological modelling and prediction as well as environmental assessments related to river connectivity and the evaluation of  anthropogenic impacts, all with the goal to strengthen water resilience across Europe.

The EU-Hydro 2.0 database will build upon a latest generation Digital Elevation Model (DEM) to provide highly detailed and high-quality topographic input data: the Copernicus DEM, a pan-European DEM available at 10m resolution, based on the TanDEM-X mission, supported by the Copernicus DEM at 30m resolution for catchments upstream and downstream that flow in and out of the EEA38 +UK area (EU27 + European Free Trade Association (EFTA) + Western Balkans + Turkey + UK). The production of EU-Hydro 2.0 will involve the best possible ancillary data of hydrography, land cover, and infrastructure to allow seamless integration into the DEM editing process, as well as VHR satellite data for quality control and validation. The product suite consists of eight main layers: The three main raster products are the hydrologically conditioned DEM (Hydro-DEM), the Flow Direction (Hydro-DIR) and the Flow Accumulation (Hydro-ACC) maps, supported by additional raster layers for expert hydrological use. The five vector products are the river network (Hydro-NET), water bodies (Hydro-WBO), basins and sub-watersheds (Hydro-BAS), a product on artificial hydrographic structures (Hydro-ART) and a coastline (Hydro-COAST). All layers will be interrelated, scalable and logically consistent. The approach aims at transparency and automation to-the-extent-possible, supported by manual corrections where needed to increase quality and meet user requirements. This will ensure efficient and reproducible data processing and facilitate further updates of EU-Hydro into the future.