More Than 60% of Japan's Sandy Beaches Could Disappear by 2100, Experts Warn

Japan's sandy beaches are steadily shrinking. For about 40 years following World War II, the primary cause was reduced sand reaching the coastline because of dam construction and river sand extraction, Yongho Lee reported for The Mainichi.

The average width of Japan's sandy beaches narrowed from about 63 meters in 1950 to approximately 43 meters by 1990.

In recent years, however, experts say rising sea levels caused by global warming have become an increasingly significant factor. According to specialists, more than 60% of the sandy beaches that existed in 1990 could disappear by 2100.

Poles bearing "No Entry" signs now line sections of the coast.

This summer, the city of Hokota in Ibaraki Prefecture decided not to open Otake Coast Hokota Swimming Beach, once known for its long sandy shoreline and scenic views that earned it the nickname "Ibaraki's Gold Coast."

Wave erosion has stripped away much of the sand, exposing buried concrete seawall blocks and making swimming unsafe.

According to the Ibaraki Prefectural Government and other sources, erosion began in the 1970s and 1980s.

Experts believe sand stopped reaching the coastline because dams and port construction trapped river sediment, while increased sand extraction for concrete further accelerated beach erosion.

Other well-known beaches across Japan face similar challenges.

At Chigasaki Beach in Kanagawa Prefecture, a popular surfing destination, the shoreline has steadily retreated. In 2019, part of a nearby road collapsed during a typhoon because of coastal erosion.

At Kujukuri Beach in Chiba Prefecture, one of Japan's longest sandy coastlines, the prefectural government has built artificial headlands to slow sand loss.

Research by Keiko Udo, a professor of coastal engineering at Tohoku University's Graduate School, and her colleagues found that the average width of Japan's sandy beaches narrowed from about 63 meters in 1950 to approximately 43 meters by 1990.

Their total area also declined to about 60% of its former extent.