As part of its measures to deal with the hot conditions expected at the 2020 Tokyo Olympic and Paralympic Games, on Aug. 13 the Tokyo Metropolitan Government conducted an experiment to measure the effects on pavement surface temperature of spraying the road surface with water. Data from the experiments were released to the media.
The experiment was conducted from 4:00 a.m. to 10:00 a.m. along a 120 m section of sidewalk along Uchibori Street in the Imperial Palace's outer gardens in Chiyoda Ward. In the experiment, open-ended tubes used in agricultural work eres placed at the edge of the sidewalk to supply water. Surface temperature readings were taken every 30 minutes for three different experimental scenarios:
- spraying water beginning at 4:00 a.m.
- spraying water beginning at 7:00 a.m.
- not spraying any water
The experiment found that where water had been sprayed, the road surface temperature remained in the 27 to 29˚C range even when the air temperature exceeded 30˚C. Where no water had been sprayed the surface temperature exceeded 30˚C. "Today was a cloudy day, so the difference probably wasn't as great as it would have been on a sunny day," commented commented Tokyo Olympics and Paralympics Operations Manager Nobuaki Takahashi.
The actual Olympic Marathon course will be on the road itself, but the Metropolitan Government is exploring measures to mitigate the dangers the heat will present to spectators on the sidewalk.In addition it is planning other measures including misters that will spray athletes with a fine mist of water, and installing heat-surpressing pavement along the marathon course.
"Dealing with the heat is one of the major challenges of the Tokyo Games," said Takahashi. "We went to take a variety of steps to ensure an enjoyable experience not only for the athletes but for the spectators watching the competition."
translated and edited by Brett Larner