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On a stretch of the Chigasaki coast of 1.4 km length extending between Chigasaki fishing port and Chigasaki artificial headland, beach nourishment using coarse materials has been carried out since 2006. Since the start of beach nourishment, various monitoring surveys have been carried out investigation beach changes and verify the effect of beach nourishment. In this study, various monitoring data such as the narrow-mutibeam survey and photographs of the shoreline taken from a fixed position were analyzed. It was found that the beach width of the coast was significantly increased by beach nourishment, and it was effective.

The shoreline changes in an area of 30 km length on the eastern Bali coast were investigated using aerial photographs taken in 1981/82 and a satellite image taken in 2011. A field observation was carried out on November 24, 2011 to investigate the present coastal conditions, and the erosion mechanism was studied. It was concluded that large-scale shoreline recession occurred as the reduction process of a river mouth delta owing to a decrease in fluvial sediment supply from rivers and to riverbed mining around the mouths of the Ayung and Unda Rivers.

In constructing the Irabu bridge connecting Miyako to Irabu islands, a causeway was exended as part of the bridge on the reef flat, resulting in the formation of a wave-shelter zone on both sides of the causeway. After the construction, marked beach changes occured on the carbonate surrounded by a coral reef, and the nesting sites of the sea turtles were extensively lost. The BG model (a three-dimensional model for predicting beach changes based on Bagnold's concept) was applied to predict these beach changes. Then, the stabilization method of the beach was considered. A suitable measure was to install groins as well as beach nourishment.