A morphometric and granulometric analysis of shingle beaches in Malta

Abstract

Shingle, ranging in size from two to two-hundred millimetres, accumulates in coarse-clastic reflective beaches. On the Maltese Islands, shingle beaches constitute a very particular geomorphological niche. The marginal occurrence of this type of beach sediment requires a tailored investigation to cater for the granulometric and morphometric parameters of shingle size and shape. Despite this, very few studies have pursued the analysis of such a beach environment. This dissertation aims to provide a deeper understanding of the morphodynamics of three shingle beaches in the Maltese Islands, namely Mistra Bay and the two bays that make up Fomm ir-Riħ area. The variability between these pocket beaches and their inherent processes at the spatial and temporal scale are important. Grain-size distributions can also be understood in terms of the principle of sediment grading whether along the shore or in the cross-shore direction. Through qualitative and quantitative data collection procedures, the beach profile slope, sediment dimensions and the degree of sediment roundness were recorded in a number of fieldwork sessions per shingle beach. The research culminated with the investigation of the relationship between the sediment size distribution and the beach slope of the chosen shingle beaches. Moreover, this dissertation factored for the wind exposure of the individual beaches and its potential influence on particle size and shape. A multitude of data visualisation techniques were utilised to provide a holistic understanding of the dynamic processes on shingle beaches.