Compartmentalisation of beachface sediments along the southwestern coast of Australia

摘要

Identification of littoral cells is a prerequisite forthe determination of sediment budgets on sandy coasts. In thiscontext, the aims of the project were, first, to investigate theapplicability of statistical techniques, particularly auto-correlationand cluster analysis, to the definition of littoral cell boundaries;second, add detail to sedimentological and environmentalobservations previously reported for the southwestern Australiancoast; and third, provide a basis for future examination of sedimenttransport in a nearshore environment that is generally subject tolow wave energy. The alongshore component of sedimentcompartmentalisation has been determined for the sandy beachesof the study area and relationships between environmentalparameters and beachface sediment characteristics have beenestablished. Using data describing textural and compositionalattributes, the systematic alongshore variation in sediments wasdetermined from the cluster analysis and auto-correlation. Resultsfrom the grouping of sediments were then used in conjunctionwith geomorphic variables to determine boundaries of sixsediment compartments. Littoral cells are better developed on thesouthern sector of the coast where shoreline salients and headlandsare larger and act as boundaries. These barriers limit, but do notprevent, inter-compartment sediment transport. The findings of thisstudy provide a context for further investigation of littoral celldynamics and coastal sediment transport. The statistical techniquesapplied to data describing the alongshore distribution of sedimentsare readily repeatable in other contexts and have generalapplicability and offer a rigorous procedure for definition ofcoastal regions. 1999 Elsevier Science B.V. All rights reserved.