Beach and Sediment Characteristics at Costa Banderas, Mexico : Using Distribution Content Analysis to determine origins of Beach Sediment.

Costa Banderas, a 300-hectare property located on the northern shore of Banderas Bay on the Mexican Pacific coast, is to be developed for tourism. Its 8-kilometer coastline is composed of three long beaches and several narrow pocket beaches that are separated by protruding cliffs and rock outcroppings. Freshwater runoff is present at seven locations along the coast of Costa Banderas through streams that vary in magnitude. Sediment samples collected along the profile lines were analyzed for calcium carbonate content and grain size distribution. These parameters show a pronounced variation in the long-shore direction but not in the cross-shore direction. Streams and cliffs in Costa Banderas were sampled to determine the possible origin of the clastic portion of the beach sand. A Distribution Component Analysis (DCA) was carried out on the beach and stream samples. Relatively good alignment of the normal components of stream and adjacent beach samples is found for the three larger streams. This emphasizes the importance of these streams as sediment sources. A conceptual solution to attenuate Sea conditions by means of a submerged breakwater is presented.