Identifying the rates and risks of coastal erosion hazards around the Northern coast of Malta

Abstract

Throughout the years, experts and professionals from various disciplines had vigorously studied hazards and risks. A hazard is usually defined as being the probability of something to change within a specific time frame and a specific area. In fact these hazards vary from earthquakes, volcanic eruptions to landslides to soil erosion and even coastal erosion. Coastal erosion can in fact be considered a geomorphic hazard. Several writers and the recent EU wide study, EUROSION, regard it so. With regards to Malta, however most of the emphasis was given to study the vast diversity of coastal morphological features present along the islands. However Malta had been influenced by subsidence during the Quaternary ages and this led to the creation of submerged and emerged coastlines. The emerged coasts are situated on the west, northwest and southwest parts of the island. From the theory of Valentin (1952 in Ingerbretsen et al., 1997) one may expect that where submergence takes place there is usually a retreat of the shoreline due to coastal erosion. However where emergence takes place there could be maybe the process of deposition. Since Malta has a land area of only 315 km2 the study looked at whether coastal erosion can be regarded as a hazard along Northern Malta. Most of all it looked at the regional risks in two case study areas. The methodologies used to discover such risks were various and these related to coastal land use, geomorphology and even processes at both bays. The results that emerged from these methodologies were various and some also contradicted those that local authors had assumed for decades. The study also analysed whether the theory of subsidence and emergence is true with regards to the Maltese Islands. For this reason two case study areas, Ghajn Tuffieha Bay and Mistra Bay were taken to see whether emergence and submergence respectively influence the bays. The study concludes by giving two hazard maps for each of the case study areas and maintains that there are various objectives that authorities may take to mitigate coastal erosion. However one can conclude by saying that further studies are needed that deal with the coastal erosion hazard and its management. This is due to the fact that coastal erosion is an ongoing process, which develops as a hazard only where there is human interference at the coastal zone. Keywords: coastal erosion, hazard, emergence, submergence, geomorphology, human interference, management.