The effects of urbanization on the intensity of the urban heat island : a case study on the city of Kuala Lumpur

Abstract

The focus of this study is on the effects of urbanization on the intensity of the urban heat island, through a case study on the city of Kuala Lumpur (KL), Malaysia. The study aims to identify whether there is a relationship between the level of urbanization and the intensity of the urban heat island of the city as well as to what extent this relationship goes. There are two methodologies followed in this study. Firstly, the methodology to study the urbanization process in KL by collecting data from secondary and primary sources of data and by reviewing the literature along with official documents. Secondly, there are two methodologies combined to study the horizontal nocturnal urban heat island of KL by using weather station networks method and traverses survey method. The parameters included for studying and measuring the levels of urbanization in the city are population density, traffic activity and land use change. Moreover, the three parameters are measured using traverses survey method; air temperature, relative humidity and wind speed levels. The study shows that, the level of urbanization is proportional to the values of temperature registered, while the temperature clearly varies from weekdays to weekends. The working days are relatively hot compare to non working days. Nevertheless, it is difficult to relate the relative humidity values only to working or non working days. The relative humidity can be related to green or non green areas, as well as to location and human activities among those specific areas. Furthermore, it is difficult to relate wind speed levels to the day of the week, while there is a strong relation between the wind speed levels and the location of the station. The further away the station from of KL city center, the higher the levels of wind speed. The study shows that, wind speed levels are inversely proportional to the level of urbanization of the city. The study indicates that, the increase in the intensity of the UHI of Kuala Lumpur City since 1985 reaches 1.5 o C. Furthermore, it shows that, the location of UHI nucleus has shifted from Chow Kit area in 1985 to Puduraya area (2004). The study concludes that, the intensity of the UHI of the city is proportional to the commercial, road and rail reserves land use and inversely proportional to the open space and recreational, residential, industrial, institutional, and agricultural/ fishery/ forest land use. Furthermore, the intensity of the UHI is also proportional to the population density, number of cars and motorcycles vehicles, while it is inversely proportional to public transport vehicles. Therefore, the study concludes that, the level of urbanization is directly proportional to the intensity of the UHI of Kuala Lumpur City.