A simple water sprinkling tradition in Japan, known as Uchimizu, is effective to cool down the hot temperature in the summer. The study from the Delft University of Technology shows that the simple tradition is effective to bring down the temperature in the city.

Uchimizu is a Japanese summer tradition to sprinkle water on the ground to cool the surface and prevent the dust during the hot summer day. It has been a common tradition since the 17th century in Japan, but now scientists find the tradition is effective to cool down the temperature in the city.

A researcher from the Delft University of Technology, Anna Solcerova finds the tradition is able to bring down the temperature in the hot city. In her study, according to the Delft University of Technology official news release, Solcerova measures the effect of Uchimizu to the temperature using the 3D Distributed Temperature Sensing (DTS). The measurement technique is extremely precise and accurate to record the temperature.

The measurement is taken using a large cube with fiber optic cable, after Solcerova and her colleague Tim van Emmerik poured water around the cube. The measurement tool is able to measure the temperature above the pavement. Van Emmerik designed the measurement tools with his friend Koen Hilgersom.

Her study finds the Uchimizu generally always works to bring down the temperature as the ground become cooler. In order to achieve the greater effect, it is better to sprinkle the water when the heat is less intense.

"We show that this simple method of sprinkling water has the potential to considerably reduce extreme heat in paved urban areas," Solcerova said. "In addition, uchimizu presents an opportunity to increase the awareness of city dwellers and to encourage them to solve heat stress and to save energy."

Solcerova presented her findings at the annual conference of European Geoscience Union (EGU) General Assembly in Vienna, Austria from April 23 to 28. According to the event itinerary, she presented her findings on Wednesday, in the "Urban Climate and Urban Biometeorology" session of the conference. Watch the footage from Solcerova's temperature recording in the 13 mm to 859 mm above the block pavement below: