Photo/Illutration A surfer takes a morning stroll at Aoshima beach resort in Miyazaki. (Asahi Shimbun file photo)

  • Photo/Illustraion
  • Photo/Illustraion

The seaside summer playgrounds of this island nation are not as busy as they used to be, and it appears to be because the sandy shorelines are disappearing--fast.

The number of visitors to beach resorts in Japan has slid from 37.9 million in 1985 to just 6.6 million in 2017, according to the public interest foundation Japan Productivity Center’s annual “White paper on leisure.”

The figure is well below that for overseas travelers in 2017, at 11 million.

Sandy beaches have been lost rapidly in postwar years, partly owing to coastal development, as well as dam construction and digging for gravel, which has caused less sediment to flow from upstream areas into seas.

The average width of sandy beaches across the archipelago fell from 70 meters around 1900 and 66 meters around 1950 to just 43 meters around 1990, according to a study by Keiko Udo, a Tohoku University associate professor of coastal engineering, and her colleagues.

The impact of global warming is another concern, with an expected rise in sea level causing the coastlines to recede further than submergence alone.

Calculations based on forecasts for the late 21st century indicate that 40 percent to 90 percent of sandy beach areas will be lost by that time, Udo said.

Rough waves from strong typhoons also pose a threat.

"A sandy beach relies on a balance of sand influx and sand loss," Udo said. "Once lost to a considerable extent, a beach is no longer easily restored."

Sandy beaches afford scenic landscapes and sites of recreation for people of all ages. They have also cradled rich ecosystems, including spawning grounds for sea turtles.

Seas with a gently shelving seafloor are beneficial for disaster management, as they lessen the force of waves.

The difficulty is that sandy beaches change day to day depending on the sea current and the amount of sediment.

Measures are being taken in some beach areas to bring in sand or use structures to mitigate sand loss. However, there are limits to what can be done through such projects, and they tend to be very costly.

In a written proposal worked out in June, an expert panel under the land ministry called for a transition from retroactive response measures to adaptive management, with an emphasis on forecasting.

The recommendation proposed a new approach of conducting "checkups" on sandy beaches to determine how they are changing and the factors at play. It said that changes should be predicted and preventive measures should be taken at the same time so that the width of sandy beaches can remain at levels deemed necessary for the respective regions they are located in.

The Coast Law amended in 1999 calls for coastal management that puts emphasis on the environment and use alongside the objective of disaster management, such as the construction of banks. Twenty years on, however, authorities have yet to fully grasp the state of sandy beaches across Japan.

The recommendation calls for taking a survey of the situation from a broad perspective, including upstream areas, and studying preventive measures in an ongoing manner.

"Continuing to take partial measures, as we have been doing, holds no prospects for the future," said Satoquo Seino, a Kyushu University associate professor of ecological engineering, who is on the panel. "There is a long way to go, but we need a new approach put into practice in whichever regions doing so is possible."

Talks within local communities and cooperation among organizations concerned are key to the new approach.

Another recommendation was also worked out by the panel a year ago on tsunami disaster management measures. It set forth the idea of evacuation plans and community development initiatives, not relying solely on coastal levees.

There should be talks on community goals based on reality with respect to both themes and a combination of various measures.

Authorities came under fire for building coastal levees in a manner that was at odds with the ideas of residents in communities affected by the Great East Japan Earthquake and tsunami disaster in March 2011.

The time has come to set aside differences and discover ways to meet all the goals of protecting the environment, managing disasters and preserving the charms of seaside areas.