SOME STUDIES ON THE EARTHS SURFACE CONDITIONS RELATING TO THE URBAN HEAT-ISLAND

The recent studies of the earth's surface conditions relating to heat islands in Japan are presented from geographical viewpoints as an activity of the Association of Japanese Geographers. Urban climate is defined as the result of urbanization, which is expressed as concentration of population, modification of earth's surface constituent materials, and expansion of living space onto and under the ground. These bring about changes in morphological and physical features of the urban surface, and its energetic conditions, which consequently and unintentionally modify radiation, heat and water balance in urban areas. Some estimations of urban surface conditions are at first explained. Surface conditions treated in this study are morphology of urban surface (mainly building height), roughness, sky view and energy consumption. Next, the relationships were considered between air temperature and surface morphology, heat island intensity and population, population and sky view factor, respectively. Finally the regional differences in heat islands were discussed, and the necessity of urban climate studies to ameliorate human and global conditions.