This paper describes a field measurement of urban thermal environment and a three-dimensional simulation of urban heat island in Tokyo metropolitan area. The field measurement results show that the present status of ambient temperature, relative humidity, and radiative heat flux in an urban street canyon in typical summer condition. The simulation results show that the maximum ambient temperature increase up to 45.5℃ in 2031, and also show that the effect of “Tokyo wall” which is a cluster of high-rise buildings. The ambient temperature increase around the Tokyo wall is less than 0.1℃.

Time-space distributions of energy supply both by electricity and town gas in Osaka city were investigated precisely in order to estimate effects of local artificial heat generation on the heat island phenomena. Daily variations of electric power supply of 20points of secondary substations during July 13th to July 27th in 2000 were presented and analyzed in the paper. Also, monthly town gas supply amounts at each "ku" of Osaka city were presented from April 2002 to March 2003. And those data were drawn on the map by using geographic information system and were analyzed in order to determine diurnal variation of local energy supply characteristics. It was revealed that the electric power supply amounts per unit floor area are quite different between central commercial and business area and suburban residential area. The amount of electric power supply per unit floor area became 430W/m2 in the city central part with many commerce and amusement facilities. And the amount of maximum power supply per unit total floor area at central commercial and business area was nearly 100 W/m2. Meanwhile, the amount of maximum power supply in suburban residential area was nearly 10 W/m2. Moreover, many town gas was supplied at both central commercial and business area and the coastal industrial area. The amount of maximum supply of the town gas in July were about 50W/m2 at central commercial and business area and about 10W/m2 at suburban residential area.

There are 2 kinds of typically experimental method to survey urban heat island (UHI) phenomena: one is to analyze air temperature differences between urban and rural meteorological observatories; the other is to monitor horizontal temperature distribution by a mobile measurement from urban area to rural area. An advantage of the latter method is high spatial density of measured data. This paper proposes mobile measurement system for observing nocturnal urban heat island (UHI) phenomena and shows horizontal temperature distribution of the Osaka Plain. This paper shows a case of coastal supercity, Osaka, which has climatological problems caused by urbanization. For example, the daily minimum temperature has been kept high during the night in summer; the time to change from sea breeze into land breeze has been later. In this paper the horizontal temperature distribution in the Osaka Plain has been observed in the period of August - December 2005 using the mobile measurement system with GPS receiver. The mobile measurement system enables to measure some parameters while moving extensively at high speed, so that observation area during a few hours is expanded. The center of Osaka City had been higher than the average through the observation period. In winter Osaka bay coastal part has been higher area, while in summer the eastern part of the Osaka Plain has been higher area. The northern part and the southern part of the Osaka Plain have been found lower temperature area. UHI intensity is defined differences between average temperature of the center of Osaka City and that of the northern part or the southern part. Negative correlation between UHI intensity and infrared radiation has been pointed out. The maximum value of UHI intensity is 5 degree C, which has been observed on Nov. 9th.

Osaka City region is located on a coastal area, about 20km square, and the air temperature is notably higher than the circumference area in summer. In order to characterize the air temperature distribution of Osaka City, in summer of 2005, data were taken from 24 stations in the city operated by the Osaka City Environment and Sewerage Bureau. Also, data set of wind and temperature were taken from other 18 air monitoring and weather stations.
The city area was divided into the west, the central, and the east area, and air temperature of each area was averaged in each time zone. At daytime, the air temperature rose from the west to the east. On the other hand, at night and early morning, the central area was the highest.
The wind direction and velocity are the critical factors of the heat island in Osaka City, and the feature of the air temperature distribution was able to be confirmed by the measurement.

Recently, in many cities, thermal air pollution has arisen from superfluous progress of the increase in artificial waste heat and covering, and loss of natural space. Consequently, in the city, compared with the suburbs, temperature becomes high and the heat island phenomenon has appeared. As the measures, it is very important to control the radiation. Therefore, we notice membrane materials which have small solar absorptance. In this study, we selected three membrane materials of polytetra fluorine ethylene (white, gray, yellow green), and these solar absorptances and infrared emissivities were measured. These solar absorptances were 0.19, 0.53, 0.70 and infrared emissivities were about 0.9. We applied the measured values to the math calculation and evaluate surface temperature for construction and sensible heat flux to the atmosphere. Consequently, the surface temperature is lower and the sensible heat flux decreases. So, it is expected that membrane materials mitigate the heat island phenomenon.

This paper presents an environmental economic modeling, in which I propose heat island integral to represent the force of heat island and urban heat island function. Also presented is a heat island tax/subsidy scheme; the subsidy based in the numerical data of tree carbon fixation is given to contributers to cooling the city by providing vegetation in the city. In our model any metropolitan resident consumes goods and have landscape gardeners plant trees in his/her gardens, and producers supply goods. Every emitter emits heat and gases in the atmosphere, which results in urban heat island and an anormous amount of cost, so that it is a recent economic problem of great importance for large cities such as Tokyo. This paper tries to give an economic theoretical solution to this prolbem.

In this paper, it surveyed about the high albedo pavement which performed high reflective surface preparation to open grading asphalt paving, and the following result was obtained.
1) By forming a paved surface into high reflection, it validated that a surface temperature was reduced greatly. In the result of a measurement in the fine weather day of a summer, it is set to 6.8 (K) with the reflection factor 0.25, and becomes the temperatures fall of 20 (K) in the reflection factor 0.6.
2) Based on the radiation balance of the solar radiation obtained from survey, and long wave radiation, operative temperature was calculated and the trial calculation of the influence on the effective temperature was made. According to this, by the weather condition in the daytime in the survey day of summer-season fine weather, when a pedestrian stood on the pavement central part, a result in which operative temperature carries out 3.4-6.1 (K) ascent was brought. Since increase of reflected solar radiation exceeded the reduction effectiveness of the long wave radiation injected from a pavement side, the whole radiation absorption increased.
The heat conductivity and volumetric specific heat of the pavement body were presumed based on the actual measurement, numerical computation was carried out using this, and the following results were obtained.
As a result of performing a case study about the relationship between solar reflectance and a surface temperature, in the weather condition of the survey day, the result which the temperatures fall of 2.5 (K) produces was obtained to the Increase of value in the reflection factor 0.1.

The AIST developed a multi-scale analysis model to assess the countermeasures against urban heat island phenomena. The model consists of three sub models; urban climate model, multi-layer urban canopy model and building energy consumption model. The overall performance is fairly good. Because it is too heavy for the full-spec model to assess the countermeasure around a year, the combined model of urban canopy and building energy consumption model was used to assess the countermeasures. The results demonstrate that photo catalyst, solar reflective painting and the ground source heat pump are promising countermeasures.