Temporal Variations of Urban Heat Island Intensity in Three Major Cities, Thailand

Yenrutai Jongtanom,Charnwit Kositanont,Surat Baulert

doi:10.5539/mas.v5n5p105

Abstract

The mean maximum urban heat island (UHI) intensity in three major cities in Thailand was investigated by using data measured at two meteorological observatories (an urban site and rural site) in each study area for the period 2004 to 2008. Thermal contrasts between the urban and rural sites were positive which indicated that most of the time the air temperatures at the urban sites were higher than the air temperatures at the rural sites. The strongest mean maximum UHI intensity occurred in the nighttime and in the early morning, while the weakest mean maximum UHI intensity was reached during the daytime. The results indicated that UHI events occurred more frequently in the nighttime than in the daytime. Seasonal analyses showed the mean maximum UHI intensity was weakest in the rainy season (May-October) and was strongest in the dry season (November-April).

Highlights

The urban heat island (UHI) phenomenon is considered to be one of the major problems for human population in the 21th century as a result of urbanization and industrialization (Zhou et al, 2004; Rizwan et al, 2008; Zhang et al, 2009)
The diurnal variations in UHI intensity were shown in Figure 1.The mean maximum UHI intensity at all sites were positive which indicated that the air temperatures at urban sites were higher than at rural sites most of the time
The greatest mean maximum UHI intensity occurred at 04:00 LST in Bangkok (2.24 ํ C), at 07:00 LST in Chiang Mai (2.73 ํ C), and at 22:00 LST in Songkhla (2.42 ํC)

Summary

Introduction

The urban heat island (UHI) phenomenon is considered to be one of the major problems for human population in the 21th century as a result of urbanization and industrialization (Zhou et al, 2004; Rizwan et al, 2008; Zhang et al, 2009). There have been few studies of UHI in Thailand This present study investigated the mean maximum UHI intensity in three major cities in Thailand by using the maximum temperature from the period 2004 to 2008 recorded at selected urban and rural weather stations. It focused on: (1) diurnal variations in UHI intensity (2) seasonal variations in UHI intensity

Study sites description and Data processing

Data processing

Diurnal variations in UHI intensity

Seasonal variations in UHI intensity

Conclusion