Ganesh, R. and Gopaul, N., 2013. A Predictive Outlook of Coastal Erosion on a Log-Spiral Bay (Trinidad) by Wave and Sediment Transport Modelling

Coastal erosion is increasingly becoming a significant concern (economic and recreational) on considerable stretches of Trinidad's coastlines. Modelling investigations were undertaken into the impacts of time varying wave climates on coastal stability issues on Guayaguayare Bay, SE Trinidad. Erosion is currently occurring at an approximate rate of 0.6m per year (8-yr average). By utilising a wave dataset of approximately 5 years collected at both offshore and nearshore locations, a good appreciation into incoming wave energy was gained. Wave transformation modelling was carried out using DHI's MIKE21 SW. Increases in wave energy were found to be directly influenced by the North Atlantic winter storm period. Therefore, some variance in erosion rates, at different times of the year exists. Sediment transport across the bay was investigated using MIKE21 ST and LITDRIFT to determine volume variations. By using MIKE21 SW, transformed wave parameters at the shoreline were accurately obtained. Certain high risk zones were therefore identified as related to on-going coastal erosion. An insight into the seasonality of sediment transport processes (wave driven) taking place along this bay is now better understood but given a longer dataset more accurate quantifications can be made. Finally, net erosion/accretion zones were identified which can aid the coastal engineer/manager in making future infrastrucutural development decisions.