Masakazu Moriyama

Earth surface heat balance changes caused by urbanization

Abstract The relationships, in regional environmental planning, between land use and earth surface heat balance in urbanized areas have been investigated. In the first part of this study, the calculation procedure and field observations of earth surface heat balance (natural heat) are described. The summer earth surface temperature was observed at Tokyo. Calculated values showed good agreement with observed values, though observed surface temperatures varied widely with differing land use. The results of an Osaka Prefecture (1856 km 2 ) case study are also presented. The amount of natural heat (the earth surface heat balance) and the artificial heat released are estimated according to land usage. The regional mean earth surface temperature in Osaka City (a developed region) during August is higher by ca. 3 °C than it is in Sennan district (an undeveloped region). The artificial heat released was 174.2 × 10 12 kcal/year in Osaka Prefecture (1970 – 1974). The heat flow at the earths surface varies remarkably with urban development.

Making method of “Klimatope” map based on normalized vegetation index and one-dimensional heat budget model

Abstract “Klimatope” means a unit of climate based on land cover conditions. In this paper, the following seven land cover elements are chosen for the “Klimatope” categories in the Kobe area; water surface, forest, park, suburban, city, city center and factory. The air temperature is simulated for each “Klimatope” to make its characteristics clear using the one-dimensional heat budget model. The coefficients related to the earth surface heat budget for each “Klimatope”, are estimated by Landsat TM data and the summing data of town information for each street. The “Klimatope” categories are discriminated based on the calculation results of the minimum air temperature. Especially, the city area (“city center” and “city”) and “suburban”, “park” and “forest” are easily able to be classified using the NVI value. Finally, the “Klimatope” map of the Kobe area is produced.

Control of urban night temperature in semitropical regions during summer

Abstract In summer, weather in urban areas of the south-east region of Japan is humid and hot. It seems that the heat-island effect in urban areas on human life is greatest at night during summer, because hot and humid weather inhibits sleep thereby leading to poor health. A prediction model for urban air temperatures is needed in order to develop countermeasures for thermal environmental problems. The estimation of air temperature within the constant flux layer is based on a one-dimensional heat balance. Further, using the Monin-Obuklov length, momentum, heat and moisture fluxes are calculated to account for atmospheric stabilities. This paper discusses a study of the influence of atmospheric stabilities on the formation of nigth temperature within the basic concept of a ‘heat transfer coefficient of the surface boundary layer’. The results clearly indicated that the greatest causes of the increase of night temperatures in urban areas are the release of artificial heat and heat storage in soil. In conclusion, from the results of this investigation, a concept of the required green-area ratio needed to control urban night temperatures is proposed.

An Evaluation of Urban Land Use Regulations from View of Urban Surface Albedo

abstract Urban surface albedo, which is one of the important factors of the urban heat island phenomenon, was used to evaluate urban land use regulations. Broadband albedo at the surface level of Sakai City, Japan, was calculated, and effects of land use regulations and actual land use were estimated using satellite remote sensing data, a land use regulation map and detailed digital information expressing actual land use. Land use regulations define land use, maximum building coverage ratios and maximum floor area ratios, which relate the heights of buildings to the areas of their sites. These factors have effects upon broadband albedo and each narrowband albedo corresponding to wavelengths observed by Landsat ETM+. Albedo values differed according to land use regulation zones. The combination of land use regulation and actual land use is also meaningful in grasping urban surface albedo. But this relationship may provide only slight insight into the urban heat island phenomenon.

Analysis of Land Use Zoning Regulations and Green Coverage Ratio

The purpose of this study is to make clear the relation between Land Use Zoning Regulations and Green Coverage Ratio in Japanese urbanized city. It is probable that Land Use Zoning Regulations has an influence on Green Coverage Ratio for its restrictions to building form and use. However, this relation is not clear. For creating and protecting green area in urbanized city, it is important to consider the influence brought by land use zones. The study area was selected in Sakai City, Osaka, Japan. Green Coverage Ratios of past 3 terms in the study area were estimated by satellite remote sensing data (LANDSAT5-TM data), and its changes were analyzed statistically using GIS. The results of this study show that there are some tendencies of Estimated Green Coverage Ratio′s change in each land use zones. And this means the possibility to take control of Green Coverage Ratio in urbanized city and give supports to the establishment of the green area-related laws by Land Use Zoning Regulations.

Land Cover Analysis Using Fine Resolution Satellite Data and GIS Data

abstract Normalized vegetation index (NVI) and albedo are computed using the fine resolution satellite remote sensing data. The characteristics on their frequency distributions for corresponding land uses are analyzed by superimposing the Detailed Digital Information on them. The frequency distributions generated by raw data in 10m meshes under consideration are compared to these made by the averaged data in each 10m meshes which seems to represent the popular course resolution satellite remote sensing data. By using these fine resolution data together with the GIS, albedo of the building roofs and roads seem to be distinguished. The characteristics on the frequency distributions of NVI and albedo for individual land uses are examined, and these for the raw value of 4m mesh are shown to be almost similar to those for the averaged value in 10m mesh. However in some land use categories, the specific materials of land cover contained in the categories are found to enlarge the standard deviation.

A study on the distribution of salt concentration in the atmosphere at coastal areas

Abstract Due to a recent increase in development projects along coastal areas, various forms of salt damage on structures, for example, deterioration of concrete and corrosion of steels, are being experienced at a high frequency. In order to have a better understanding of the severity of salt concentration, it is important to understand the spatial distribution of salt concentration along coastal areas. In this study, the spatial distribution of salt concentration (concentration of the chlorine ion) in the atmosphere was investigated by field observation. The values of field observation were compared with the results which were calculated by a two-equation model of turbulence. The calculated results of vertical distribution of salt concentration agree with the values of field observation. The calculated results of horizontal distribution showed lower values than the observed values, possibly due to the dependency of salt absorption rate on surface concentration.

Estimation of land cover ratio using remote sensing data (LANDSAT MSS) for investigating thermal properties of urban areas

Abstract In order to develop countermeasures to thermal environmental problems in urban areas, it is important that the thermal properties of the Earths surface, such as albedo, evaporative ratio, thermal conductivity and heat capacity, are specified. It is possible to determine these properties indirectly from land cover ratios. In this paper, a method of estimating land cover ratios is studied by using remote sensing data (LANDSAT MMS). Several methods have already been applied to estimate the green area ratio. However, land cover ratios that include not only the ratio of green but also the ratio of water surface and other land cover, such as bare earth, pavements and buildings, are needed for the purpose of this research. A multiple regression method is applied here. An advantage of this method is that it is independent of the resolution of the remote sensing data. The results of this estimation method are discussed here.