MECHANISM OF THE URBAN HEAT ISLAND CONSIDERING GEOGRAPHY AND BACKGROUND CLIMATE

Abstract

 The urban heat island (UHI) is caused by the progress of urbanization, but is considered to be influenced by various factors that differ depending on the cities, such as the geography and the background climate. However, the comprehensive mechanism is not clear yet. In this study, we tried to clarify the influence of not only urbanization, but geography and background climate by comparing the heat island phenomena of multiple cities in the world using numerical simulation. The wind speed is the main contributor to the urban heat island intensity; the heat of the city is transferred more effectively to the surrounding area as the wind speed is stronger. The wind speed is considered to be a comprehensive indicator reflecting the effect of geography around the city, and the roughness of the buildings.