FIELD INVESTIGATION ON COASTAL MORPHOLOGICAL PROCESSES OF THE SOUTH KASHIMANADA COAST

摘要

Comprehensive field measurements on waves, currents and beach morphology were performed at south Kasimanada coast facing the Pacific Ocean where significant beach erosion has been experienced in recent 30 years. Anthropogenic impacts on coastal sedimentary processes were described on the basis of grain size distribution and dating of vertical sediment cores sampled in the nearshore area. Headland structures, constructed from 1984, are found to contribute to trapping fine sand and stabilizing the shoreline. The dating of sediment stratum by using Pb-210 method revealed that the sediments at the water depth of 20m were found to be fresh within the 50cm thick surface layer. Historical change in sedimentary processes for the last 50 years were presented.