Process-based modelling of the Santo André Lagoon: Understanding of the physical processes involved in the inlet closure

Process-based modelling of the Santo André Lagoon: Understanding of the physical processes involved in the inlet closure

Stuij, S.A.

Stive, M.J.F. (mentor)
Walstra, D.J.R. (mentor)
Van Rooijen, A.A. (mentor)
Luijendijk, A.P. (mentor)
Bertin, X. (mentor)
Storms, J.E.A. (mentor)

Civil Engineering and Geosciences

Hydraulic Engineering

2014-07-11

The Santo André Lagoon is one of many inlets and lagoons that can be found along the along the Atlantic coast of Portugal. These coastal systems have a large ecological value and are important for rich biodiversity. The Santo André Lagoon is part of a natural reserve that is officially under protection of the country. It has a rich flora and fauna and is an important place for many (protected) birds. Every year during February/March the Santo André Lagoon is breached to renewal the water and to lower the water level to prevent the birds’ nests (with eggs) from flooding built on the waterline. After breaching an inlet is shaped and closes typically within weeks. Understanding of the behaviour and morphological development of the inlet until its closure is of great importance to maintain the ecological environment. Understanding of the morphological development of this artificially breached inlet is of importance to maintain the nature and its biodiversity. Previous modelling gave more insight in the processes involved in the inlet closure, but did not succeed in reproducing its closure. Reasons for not being able to reproduce the inlet closure thought to be due to the fact several physical processes were missing and not taken into account, but may be of large importance. Physical processes, such as: wave asymmetry, infragravity waves and current feedback on wave propagation (including current refraction). In this study the morphological development of the inlet of the Santo André Lagoon is investigated using the morphodynamic model XBeach that includes the additional physical processes (that were not included in previous modelling). Besides the general development, the influence and contribution of these physical processes are investigated. Modelling of the behavior resulted in better understanding, but did not succeed in simulating the closure. It suggests onshore transport is underestimated and tide may be overestimated. The contribution of the physical processes investigated has influence on the development of the inlet that may cause the closure. Even though the inlet is not closing in the model, with this study new insight is given in the processes involved in the closure of an artificially breached inlet and interesting approaches for further research.

XBeach
process-based modelling
inlet
Santo André Lagoon
Portugal

http://resolver.tudelft.nl/uuid:8c21c8e0-ef37-4242-a9ed-8ab8e3947238

38.112259, -8.799431

Student theses

master thesis

(c) 2014 Stuij, S.A.