Lagrangian transport of particles in Ria de Aveiro lagoon, Portugal

A two-dimensional vertically integrated hydrodynamic model coupled to a par ticle tracking model is applied to study the dispersion processes and resid ence time in Ria de Aveiro lagoon (Portugal). The only dispersion process that is considered in this study is the advecti on, according to the main characteristics of the local hydrodynamic. The pa rticle tracking model computes the particles position at each time step, us ing a fourth-order Runge-Kutta integration method. The dispersion of passiv e particles released along the lagoon and in critical areas are studied in this work. The residence time is also determined for the entire lagoon. The results show that the mixture between particles coming from different c hannels of the lagoon is negligible in a time scale higher than 2 tidal cyc les. The residence time for the lagoon central area is about 2 days, reveal ing a strong marine influence in this area. At the upper reaches of the cha nnels were found values higher than 2 weeks. (C) 2001 Elsevier Science Ltd. All rights reserved.