August 1st is Water Day in Japan and the first week of August is Water Week.
On August 5th, the Water Workshops and Expo was jointly held by the Headquarters for Water Cycle Policy, the Ministry of Land, Infrastructure, Transport and Tourism of Japan, the Tokyo Metropolitan Government and the Japan Water Week Organizing Committee, at the Science Museum in Kokyo Gaien National Garden in Tokyo. At the event, the Mission Uchimizu Headquarters organized a workshop twice, aiming at elementary school students who are currently on school summer holidays.
Mission Uchimizu Grand Master Shigenori Asai (Japan Water Forum Director) delivered a keynote presentation to brief the participants on why air temperature rises, how water's heat of vaporization effects, and the processes of evaporation, condensation and precipitation in the water cycle.
Accompanying adults as well as children were amazed with the difference between radiation and conduction.
After the presentation, having moved to the rooftop of the Science Museum, they experienced the changes in surface and air temperatures by doing uchimizu (pouring water) together.
Participants enjoyed uchimizu and felt a coolness on the hot rooftop.
It was measured in the afternoon session that the surface temperature of the concrete rooftop dropped from 53 to 45 degrees Celsius and that the air temperature 1.5 meters above, 33.7 to 33.1 degrees Celsius just after uchimizu. These values were further decreased in 10 minutes.
The Grand Master asked the participants where the water went when the water that you had poured dried up. Children vigorously answered, “It rises up.”, “To the sky!”, “It will form clouds.”, etc.
We were happy that they did understand the water cycle.
At closing of the workshop, the Grand Master Asai called on the participants to practice uchimizu at home by not taking tap water but utilizing stored rainwater and used water. (The workshop used highly reclaimed wastewater provided by the Bureau of Sewerage of the Tokyo Metropolitan Government.)
For more details on Mission Uchimizu, please visit at https://uchimizu.jp/en/