HR: 1340h
AN: H43D-1607 [Abstracts]
TI: Experimental and Numerical Studies of the Effects of Water Sprinkling on Urban Pavement on
Heat Island Mitigation
AU: * Yoshioka, M
EM: tt67101@mail.ecc.u-tokyo.ac.jp
AF: The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-8656, Japan
AU: Tosaka, H
EM: tosaka@geosys.t.u-tokyo.ac.jp
AF: The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-8656, Japan
AU: Nakagawa, K
EM: knaka@sci.osaka-cu.ac.jp
AF: Osaka City University, 3-3-138 Sugimoto, Sumiyoshi-ku, Osaka-shi, Osaka, 558-8585,
Japan
AB:
One of the main causes of gheat island phenomenonh is thought to be the artificial covers of the ground
surface with asphalt or concrete which reduce greatly inherent cooling effect of water evaporation from soil
surface. In this study, as a candidate method of mitigating the heat island the effects of the gwater sprinklingh
on the pavements are discussed from field experiments and numerical studies.
Three field experiments of water sprinkling on the asphalt/concrete pavements were performed in hot summer
days in 2004-2006. For detecting the change in temperatures, the authors developed and used a 3-D
measurements system which consists of two vertical planes with 6m high and 16m wide, and has network arrays
of 102 thermistors distributed spatially in the planes. The temperatures measured in and around the water
sprinkled area indicated that the ground surface temperature decreased 5 to 15 degrees uniformly in the water
sprinkled area compared with those in the un-sprinkled area, while the relative decrease of atmospheric
temperature was approximately up to 1 degree. The subsurface temperature at a depth of 14cm under the
pavement decreased significantly and kept lower than that at the same depth in un-sprinkled area over the next
morning.
A numerical model was developed and applied to interpret the experimental results. It deals with the heat balance
of radiation, sensible/latent heat transfer at the ground surface and heat conduction through the artificial and
natural soil layer under ground. temperature and vapor conditions changes at and near ground surface were
modeled by using the bulk formula.Good agreements between the calculated time-temperature profiles and the
experimental ones were obtained by assuming adequate physical parameters and meteorological conditions.
The model could be improved in order to evaluate the changes of temperature and vapor contents in atmosphere
near the ground surface caused by aerodynamic turbulent diffusion.
DE: 1803 Anthropogenic effects (4802, 4902)
DE: 1807 Climate impacts
DE: 1843 Land/atmosphere interactions (1218, 1631, 3322)
SC: Hydrology [H]
MN: 2007 Fall Meeting