Hydrological and Sedimentological Patterns in the Cabras Lagoon (Sardinia, Italy)

the Cabras Lagoon (Sardinia Sea, in Western Mediterranean Sea), the results of a 2D finite element hydrodynamical model (SHYFEM) have been compared with the observed bottom sediment distributions. This model has been used to simulate water circulation and residence time. The bottom sediment distribution has been obtained from the statistical analysis (mean diameter, sorting, skewness) of the in situ data. Analysis of the model results and observed sediment distribution indicates that there is a relation between the distribution of water current and the distribution of fine cohesive sediments (<8 micron). The sediment transport directions within the lagoon seem to be related with the gradient of water current velocity, suggesting that water circulation is responsible for the accumulation of fine cohesive sediments at the centre of the basin, where the velocity of current is low. In conclusion, these results illustrate the capability and usefulness of numerical modelling as a tool for understanding the role of hydrodynamics in the distribution and transport of sediments in lagoon environments.