Hydromorphology of the southern Baltic coastal and transitional waters – New index-based assessment method

The research aimed to develop the complete method for the classification of the hydromorphological status of transitional and coastal water bodies in the southern Baltic region with its adaptation to the current legislation and marine management requirements. The method considers impact and pressure indicators, such as infrastructure and activities carried out in coastal and marine areas, which may affect the change of hydromorphological status and habitat conditions. The methodology covers the change in hydrodynamic conditions, such as the wave regime, sea currents, freshwater inflow, and morphological changes defined by the dominant sediment fraction. The methodology is based on the seven indicators. Administrative, measurement and reanalysis data were used for their classification. The indicators scores were used for the hydromorphological quality index (HQI) calculation. Based on data from 2022, the classification of hydromorphological status showed good status in seven and moderate status in four water bodies.