琵琶湖西岸における底質特性について

Abstract

Sediments along the west beach of Lake Biwa were sampled and analyzed to investigatebeach processes which are associated with in sediment properties, especially in the region whereincident wave energy fluxes are weaker than those in usual coastal beaches or east beachesin the Lake.First, historical changes in the geometry of beaches are studied. Secondly, the incidentwave properties are hindcasted by the SMB method using wind data observed at Hikone for32 years. In four river mouth delta areas, wave refraction and energy fluxes entered intobreaker zone were calculated to evaluate the rate of longshore sediment transport.Combinning sediment, beach topography and incoming wave properties, we discuss anatural law of beach processes in terms of sediment properties, and conclude that sedimentproperties are good indexes to find out the dominant direction of longshore sediment trans-port which governs long term beach processes.