Abstract
The dependence of fine aggregate of concrete structures on sea sand increases in the western part of Japan. Both the sea-sand mining and the decrease of sand supply from the rivers may accelerate beach erosion and devastate the coastal environment. The change of longshore current due to man-made coastal structures, the decrease of sand supply from rivers, the frequent occurrence of storms, the sea-sand mining, etc. have been examined as causes of this erosion. However, what are the most essential causes still has not been revealed. The purposes of this paper are to investigate the present situation of sea-sand mining in seventeen prefectures of the western part of Japan and to examine its influence on the coastal environment.
