Using satellite and remote sensing images to evaluate the dynamic behaviour of coastal areas

Abstract

Detailed information on the dynamic nature of Maltese pocket beaches is limited, particularly over relatively large timescales. Therefore, this dissertation aims to further improve our knowledge and give an insight towards one of the largest and most impactful hazards to coastal communities and coastal areas: coastal erosion. Erosional processes on the coast are associated with many natural and human-induced factors, however, coastal erosion becomes a real threat when society does not adapt to its effects. The purpose of this study was to investigate and map changes in the dynamic behaviour of pocket beaches in Malta and Gozo through the use of satellite and photogrammetric imagery, while assessing whether each beach in question is accreting or retreating compared to a baseline. The imagery needed was collected from two main sources including; Google Earth Archives and the Planning Authority. These images were then used to create shapefile layers using an open-source GIS platform. To assess each beach, from the shapefiles collected, data on three separate parameters including changing shoreline length/m, transect length/m and area/m2 was utilised. The data obtained from the shapefiles and subsequently the charts plotted concluded that overall negative trends in the aforementioned parameters were observed in Ramla Bay and Gnejna Bay, whereas overall positive trends were seen in Ghadira Bay and Golden Bay. The areas within each beach that are most susceptible to negative trends were also outlined while also assessing seasonality patterns observed in 2019 to identify possible causes for the changing patterns observed. To properly determine the root causes of such changes observed, further investigations are, therefore, needed to determine whether the changes occurred as a result of human, geological, geomorphological factors or through the changing intensities in coastal processes such as wind, waves or currents.