| Abstract [eng] |
In this study the sediment transport mechanisms in the biggest lagoon in Europe, the Curonian Lagoon, with high river discharge and sediment loadings, were evaluated using numerical modelling. An already developed hydrodynamic model and sediment transport model were applied to the domain that represents the Curonian Lagoon. A new formula for particle settling velocity was developed and introduced into the model that allowed achieving good agreement between the modelled and measured values (40-72%). The formula is based on the findings that the organic material plays a crucial role in the system especially in the presence of cyanobacteria in high water temperatures. The model was applied for different scenarios and purposes, i.e., to calculate the sediment budget, show deposition patterns, and evaluate extreme events caused by strong winds. The analysis of all these results provided the first detailed overview of the status of the Curonian Lagoon environment, showing the important role of the Nemunas River and the influence of ice cover for the sedimentation processes in the lagoon. Moreover, the impact of the sediment resuspension in the Curonian Lagoon was evaluated and climate change scenarios were applied. Climate change projections revealed that the lagoon will accumulate more sediments in the future, forming three main accumulation zones: in the Nemunas Delta front, in the southern part of the lagoon and south of Klaipėda Strait. The developed model is a valuable tool for further analysis of the south-eastern coasts of the Baltic Sea, the Curonian Lagoon and other transitional environments as well. |
