Paving Park Sidewalks with Bamboo Chips to Address Neglected Forests, Tackle Heat Waves

By Daisuke Ito / Yomiuri Shimbun Staff Writer

15:10 JST, May 29, 2024

KOBE — The idea of paving a walkway with bamboo chips, proposed by a high school student in Kobe, seems to be a promising solution to the problem of neglected bamboo forests and to tackle heat waves.

A walkway paved with bamboo chips made from finely crushed bamboo will be unveiled in Isogami Park in the city’s Chuo Ward, which is currently undergoing redevelopment.

Students at Mikage High School in the city’s Higashi-Nada Ward were studying the problem of neglected or abandoned bamboo groves last year and proposed ideas to make efficient use of bamboo. Kobe has now made one such proposal a reality.This idea is expected to not only help address the issue of such groves but also help mitigate heat waves, as bamboo chips have an effect of lowering road surface temperatures, compared to asphalt.

The redevelopment of Isogami Park is part of the city’s Sannomiya Urban Redevelopment project. A new gymnasium was constructed in July 2022, and renovation of other areas began in September last year.

New features include playgrounds and swings in the park. The Healing Garden section in the park, which hosts a pond and plantings, uses about one ton of bamboo chips, each about 2 centimeters long, for a 1.2-meter-wide walkway, for a total of 225 square meters.

The basis of the project came from a proposal made by a Mikage high school student.During a class for first-year students in the 2023 academic year, the school took up the topic of abandoned bamboo groves — a nationwide problem as a potential cause of landslides, for instance.

The students proposed ideas to Kobe in October last year, such as turning bamboo into playground equipment or cosmetic products. One such idea was to use bamboo chips as road paving material.

According to Prof. Kenichi Sato of the Faculty of Engineering at Fukuoka University, who is familiar with utilizing bamboo, the temperature of road surfaces paved with soil or bamboo chips is about 10 C lower than that of asphalt in the summer.

Bamboo also has a higher water-holding capacity than soil, making it better at retaining water for cooling purposes for a longer time. It also has a high durability, Sato said.

Kobe accepted the proposal to use bamboo chips for the sidewalk because it was highly feasible and in line with the city’s policy of promoting measures combating extreme heat.

The city purchased bamboo chips produced by the Ogo Bamboo Project, a group of residents in the Ogo district of the city’s Kita Ward who are tackling the problem of abandoned bamboo groves. A construction company then mixed the chips with soil and cement to create the paving material.

“There are examples in other cities of using bamboo chips for pavement in terms of increased durability, but it is rare to use them as a measure against the heat,” Prof. Sato said. “Kobe City’s efforts will serve as a model case for municipalities suffering from neglected bamboo groves and heat waves.”

“I am happy that my idea was realized,” said the 16-year-old student, who proposed the project. “I hope the park will be used as a place where small children can play, the elderly can take a walk and people can relax.”