Long-term Sediment Transport in Kuzuryu River and Kaestu Coast under Sea Level Variation

Abstract

Kaetsu region has been facing problems of coastal erosion and accumulation of sediments in dams and harbors. This study aims to investigate sediment transport and its long-term changes considering sea level variation. Numerical calculation of waves and nearshore currents, together with analysis of physical properties of sand particles such as thermoluminessence, color and size were conducted to estimate the source and transport direction of sediment over geological time scale. It is found that the changes in the nearshore currents around the Kuzuryu River mouth and sediment supply from old dunes onto the coast north of the Kuzuryu River mouth are essential in understanding the sediment movement in the watershed scale.