Recent development of assessment tools for urban climate and heat-island investigation especially based on experiences in Japan

In recent years, problems concerning the urban climate-including the urban heat-island effect and urban air pollution - have attracted much attention in terms of the widespread urbanization in many parts of the world, including Japan. Assessment tools for urban climate are very important to understand effective countermeasures for heat-island mitigation. In this paper, various assessment tools are introduced and classified according to corresponding modelling scales. Special attention is given to the recent progress in Japan. It is shown that these assessment tools are very powerful at estimating the effectiveness of countermeasures. Furthermore, these assessment tools should become design tools for practical applications in the future. Copyright (c) 2007 Royal Meteorological Society.