Moving Sands- Equilibrium State of Crenulated Coasts- MOSES

Funder

Organizational Unit

Publications

Hydro-sedimentary processes in a beach-headland system

Publication . Moura, Delminda; Veiga-Pires, C.; Oliveira, Sónia; Horta, João; Nascimento, Ana; Gomes, Ana; Guerra, Liliana

Understanding hydro-sedimentary processes in space-limited environments as embayed beaches is a key question to reconstruct preterit and predict future coastal evolution forced by the mean sea level rise. Moreover, such knowledge is a fundamental management tool in areas where coastal erosion is currently a worrying fact. This work aims thus to assess the sedimentary contribute, provided by the alongshore transport, to feed embayed beaches. At the southernmost rocky coast of Portugal (Algarve), beaches occurring at the cliffs’ foot are separated by headlands connected to shore platforms forming littoral cells as a consequence of the extremely karstified carbonate landscape. The survival of those beaches depends almost exclusively on the alongshore drift.

2015Conference object

Open Access

Incorporação de Software multimédia e de informação em sistema informação geográfica

Publication . Oliveira, Sónia Alexandra Jenkins; Boski, T.; Moura, Delminda

O rápido desenvolvimento das técnicas de edição integrada de textos, imagens e sons, criou um vasto campo para produção de aplicações didáticas destinadas a todos os tipos de ensino. Conciliado com o facto das entidades financiadoras de projetos de investigação recomendarem a divulgação do conhecimento científico para um público mais alargado, fez com que durante a última década, o Centro de Investigação Marinha e Ambiental (CIMA) da Universidade do Algarve assumisse a responsabilidade de criar novos meios de comunicação entre os utilizadores da informação e a comunidade científica, por meio de plataformas multimédia interativas sobre o património natural do Algarve. Recentemente, desenvolveu a aplicação ForDid sobre o Sistema lagunar da Ria Formosa. Este sistema tem merecido uma crescente atenção por parte dos investigadores mas, para grande parte da população, a sua história, evolução e importância ecológica e social permanecem obscuros. O ForDid é um guia multimédia que segue a filosofia sistémica, simplificando e organizando a informação de modo a tornar mais claras as complexas relações existentes no sistema lagunar Ria Formosa. O presente trabalho relata a estrutura desta aplicação organizada com base nos subsistemas identificados e relacionados funcionalmente que integram a unidade fisiográfica da Ria Formosa e os processos litorais subsidiários, como é o caso do fornecimento e transporte sedimentar desde os setores costeiros localizados a Oeste. A informação gráfica que é editada com recurso aos programas multimédia SWiSH Max4 e Prezi incorpora imagens com diversas escalas espaciais, desde imagens de satélite a fotografias obtidas no microscópio. É ainda incorporada a cartografia temática criada com recurso ao programa ArcGIS Desktop. A sistematização das variáveis ambientais e dos múltiplos retro-efeitos existentes entre elas, evidencia a necessidade da gestão integradora de todos os componentes deste sistema. A Ria Formosa converte-se assim num excelente recurso didático que, devidamente apresentado graças ao caráter interativo da aplicação, irá não só facilitar a aprendizagem das ciências naturais, mas também dar a conhecer o seu inquestionável valor ambiental, sócio-económico e cultural. O trabalho proposto enquadra-se no âmbito dos projetos desenvolvidos em sistemas costeiros: PTDC/CTE-GIX/112236/2009- SIHER – “Processos de preenchimento sedimentar e a evolução Holocénica do sistema lagunar da Ria Formosa" e PTDC/GEO-GEO/3981/2012 – MOSES - "Moving Sands- Equilibrium State of Crenulated Coasts”.

2014Master thesis

Open Access

Modelling the hydrodynamic and morphosedimentary response of an beach-headland system (Algarve, Southern Portugal)

Publication . Horta, João; Oliveira, Sónia; Moura, Delminda

Future behaviour of beaches within a headland-beach system is of fundamental interest on coastal evolution since they act as a buffer between the waves’ attack and the cliffs backing them. The beaches at the cliffs’ foot anchored between headlands are space-limited environments to morphosedimentary processes.

2015Conference object

Open Access

The morphosedimentary behaviour of a headland–beach system: quantifying sediment transport using fluorescent tracers

Publication . Oliveira, Sónia; Moura, Delminda; Horta, João; Nascimento, Ana; Gomes, A.I.; Veiga-Pires, C.

Embayed beaches occurring along rocky coasts with headlands controlling hydrosedimentary processes are considered to be constrained sedimentary systems with little longshore sediment transfer between them. Such beaches are likely to narrow under rising sea level and a deficit of fluvial sediment, and because beaches act to dissipate wave energy, cliff erosion is expected to increase. Knowledge of hydrosedimentary processes in fetch-limited environments such as embayed beaches is therefore a fundamental management tool in erosionprone coastal areas such as the Algarve region (southern Portugal). The main objective of this work is to quantify longshore sediment transport (LST) using a sedimentary tracer and compare the results with the ones derived via empirical formulae from several authors. To achieve this, we establish the spatial and temporal patterns of stained sediment, and relate these to marine climate data over six tidal cycles for three adjacent embayed beaches. The values of displaced sand estimated using tracer and scaled to mixed layer depth were compared with the results of five well-known LST formulae to assess the applicability of each model to mesotidal environments. Of the LST formulae used, the CERC (2013) shows to be the most accurate in our study area. This study demonstrates the efficacy of using tracers for tracking and quantifying the sediment transport and as a basis for assessing the viability of different LST formulae for representing transport in these types of environments. The work also shows the importance of the morphological control of hydrosedimentary processes, including the disruption of longshore drift and the sediment transfer promoted by shore platforms.

2017Journal article

Restricted

The morphosedimentary behaviour of a headland–beach system: Quantifying sediment transport using fluorescent tracers

Publication . Oliveira, Sónia; Moura, Delminda; Horta, João; Nascimento, Ana; Gomes, A.I.; Veiga-Pires, C.

Embayed beaches occurring along rocky coasts with headlands controlling hydrosedimentary processes are considered to be constrained sedimentary systems with little longshore sediment transfer between them. Such beaches are likely to narrow under rising sea level and a deficit of fluvial sediment, and because beaches act to dissipate wave energy, cliff erosion is expected to increase. Knowledge of hydrosedimentary processes in fetch-limited environments such as embayed beaches is therefore a fundamental management tool in erosionprone coastal areas such as the Algarve region (southern Portugal). Themain objective of this work is to quantify longshore sediment transport (LST) using a sedimentary tracer and compare the resultswith the ones derived via empirical formulae from several authors. To achieve this, we establish the spatial and temporal patterns of stained sediment, and relate these to marine climate data over six tidal cycles for three adjacent embayed beaches. The values of displaced sand estimated using tracer and scaled to mixed layer depth were compared with the results of five well-known LST formulae to assess the applicability of eachmodel to mesotidal environments. Of the LST formulae used, the CERC (2013) shows to be the most accurate in our study area. This study demonstrates the efficacy of using tracers for tracking and quantifying the sediment transport and as a basis for assessing the viability of different LST formulae for representing transport in these types of environments. Thework also shows the importance of themorphological control of hydrosedimentary processes, including the disruption of longshore drift and the sediment transfer promoted by shore platforms.

2017Journal article

Restricted