Conserving the sandy beaches in Japan - Various approaches to coastal erosio-

Japan surrounded by sea on all sides has a very long shoreline. Due to this topographical feature, costal hazards such as tsunamis and storm surges occur frequently. While the protective function of coast has been enhanced by constructing coastal structures so far, in recent years, increasing attention has also been given to the protective function of sandy beaches. Although the devastating tsunami that resulted from the Great East Japan Earthquake that occurred on March 11, 2011 caused major damage in coastal areas, there are reports of cases where direct damage was reduced due to coastal forests and sandy beaches that attenuated the tsunami. The preservation of a safe and abundant coastal environment can be said to be the mission of civil engineering not only in the event of a coastal disaster but also at other times for public use. In recent years, the need for integrated sediment management has received much attention since local optimization could not be a fundamental solution.

In this special issue, regarding the complex phenomenon of coastal erosion, case examples that explore the clue for problem solving by employing a variety of approaches are introduced. It is hoped that, readers of this issue will better understand the reality of problems in sandy beaches, and find out the possibilities of the future civil engineering from the discussion of environmental conservation of coastal areas, which requires broad and flexible thinking.