ARTIFICIAL NOURISHMENT AND SAND BY-PASSING IN THE AVEIRO INLET, PORTUGAL – NUMERICAL STUDIES

Abstract

Artificial sand nourishment systems are a potential solution to mitigate erosion beach problems, having been applied in many cases around the world, especially in the U.S.A. and Australia. For the Aveiro inlet, the artificial sand by passing systems may be a good option, due to the availability of sediments accumulating at the north of the northern Aveiro inlet breakwater. A fixed artificial sand by-passing system can be proposed. However, fixed and continuous sand by-passing systems are the most expensive solutions. In order to reduce the economical aspect, periodic sand nourishment and semi-mobile systems are presented as an alternative. For those, different options of artificial nourishment can be proposed, depending on sediments volumes, location, distribution area, number of periodic operations, etc. Discussion about the results of the numerical simulations of shoreline evolution after different artificial nourishments scenarios at the southern part of the Aveiro inlet, in Portugal, is presented. Shoreline accretion/erosion rates, sediment transport volumes and profile sediment budgets have similar behaviors over time and along the coastal stretch, for all the tested scenarios. Generally, important coastal erosion can be mitigated with artificial nourishments and numerical modeling can help to improve the nourishments performance. For this open sandy coast, the sand nourishment simulations show better results near the deposit location for a period of time lower than 20 years. After that period, the nourishment effect is smaller. The southern profiles start benefiting with the nourishment after ten or more years.