Variability and Change in Water Cycle at the Catchment Level

This study proposes a simple methodology for assessing future-projected evolution of water cycle components (precipitation, potential evapotranspiration, and potential runoff) based on the two-level Palmer model of the soil and their impact on drought conditions at basin level. The Palmer Drought Severity Index (PDSI) is used as drought metric. The catchments of rivers Arges, Mures, Prut, Siret and Somes (mid- and lower Danube basin) have been chosen as case studies. The present climate data consist of Romanian gridded dataset, monthly precipitation and values of streamflow from Romania and Republic of Moldova and potential evapotranspiration-related data from the Climate Research Unit (University of East Anglia). We used as future projections five numerical experiments with regional models obtained through the EURO-CORDEX initiative, under two Representative Concentration Pathway scenarios. The correlations between observed streamflow at the river basin outlets and PDSI-related components of the water cycle show that PDSI represents reasonably well processes taking place in the selected catchments. Depending on the specific scenario and catchment, droughts that in the Palmer classification were deemed as incipient, mild or severe under present climate will become a normal summer feature toward the end of this century, especially over catchments situated in the lower Danube basin

A catalogue of the flood forecasting practices in the Danube River Basin

Floods are one of the most devastating natural disasters that can cause large economic damage and endanger human lives. Flood forecasting is one of the flood risk mitigation measures serving to protect human lives and social estate. The Danube River Basin (DRB) is the world\u27s most international river basin, flowing through the territory of 19 countries, covering more than 800,000%km2. The frequency of floods in the DRB increased in the last decades, urging the need for a more effective and harmonized regional and cross-border cooperation in the field of flood forecasting. Reliable and comprehensive hydrologic data are the basis of flood forecasting. This paper provides an overview of the national flood forecasting systems in the DRB. Detailed information about meteorological and hydrological measurements, flood modelling, forecasting, and flood warnings is provided for 12 countries that cover almost 95% of the total DRB area. Notably, significant differences exist among the countries in terms of the measuring network density, the models used as well as forecasting and warnings methodology. These differences can be attributed to the geographical and climatological setting, political situation, historical forecasting development, etc. It can be seen that there is still much room left for improvements of measurement networks (e.g., density, measured parameters) and models used that could be improved to enhance the flood forecasting in the DRB

Monitoring and Forecasting the Ocean State and Biogeochemical Processes in the Black Sea: Recent Developments in the Copernicus Marine Service

The Black Sea Monitoring and Forecasting Center (BS-MFC) is the European reference service for the provision of ocean analyses, forecasts, and reanalyses in the Black Sea basin. It is part of the Copernicus Marine Environment and Monitoring Service (CMEMS) and ensures a high level of efficiency in terms of operations, science, and technology for predictions and the monitoring of physical and biogeochemical processes in the Black Sea. The operational BS-MFC framework is based on state-of-the-art numerical models for hydrodynamics, biogeochemistry, and waves; analysis, forecast, and reanalysis are provided on a spatial grid with about 3 km of horizontal resolution that covers the whole Black Sea basin (the Azov Sea is not included). The scientific assessment of BS-MFC products is performed by implementing a product quality dashboard that provides pre-qualification and operational model skills according to GODAE/OceanPredict standards. Novel interfaces based on high-resolution models are part of the scientific development plan to ensure a strong connection with the nearest seas from a modelling point of view, in particular with the Mediterranean Sea. To improve forecasting skills, dedicated online coupled systems are being developed, which involve physics, biogeochemistry, and waves together with the atmosphere and, in the future, with ensemble forecasting methodologies and river-ocean interfaces