Search

In cooperation with Ho Chi Minh City University of Vietnam, beach changes on the coasts of Phan Rang City 270 km east of Ho Chi Minh City were investigated. Beach changes associated with the elongation of a sand spit and sand accumulation owing to the blockage of longshore sand transport by a jetty were investigated using satellite images together with site observation. This method combined satellite image analysis and site observation is useful for investigating beach changes in developing countries, where field data necessary for the analysis are often lacking. Preventive or mitigation measures were considered in view of Integrated Coastal Zone Management in place of the local optimization. [ABSTRACT FROM AUTHOR]

In a slender water body with a large aspect ratio, the angle of wind waves relative to the direction normal to the shoreline may exceed 45°, resulting in the emergence of cuspate forelands and the subdivision of a lake, because the fetch distance along the principal axis becomes large. The BG model (a three-dimensional model for predicting beach changes based on Bagnold's concept) was used to predict the segmentation of a rectangular lake by wind waves under the conditions with/without the construction of offshore breakwaters that reduce the fetch distance, together with the numerical simulation of the deformation of a circular lake when a straight seawall cutting off a part of the lake was constructed. [ABSTRACT FROM AUTHOR]

Topographic changes around the tip of the Mihono-matsubara sand spit with successive sand deposition into a deep sea were investigated using bathymetric survey data. Then, numerical simulation of the elongation of the sand spit on a sloping seabed with different water depths and slopes was carried out using the BG model (a three-dimensional model for predicting beach changes based on Bagnold's concept), and the relationships among the sand volume comprising the sand spit, the planar area of the sand spit, and the length were shown. [ABSTRACT FROM AUTHOR]

Beach changes near Pengambengan fishing port in the western part of Bali Island, Indonesia, were investigated by the analysis of satellite images and field observations. In this area, northwestward longshore sand transport prevails because of the oblique wave incidence from the Indian Ocean, and this longshore sand transport has been blocked by a fishing port breakwater, resulting in severe downcoast erosion. As a measure, a seawall has been constructed, instead of maintaining the continuity of the natural longshore sand transport. The adoption of this method caused further downcoast erosion. The sand bypassing method should be adopted to mitigate such erosion. [ABSTRACT FROM AUTHOR]