Urban heat island modelling of a tropical city: case of Kuala Lumpur

Abstract

The steep increase in urban populations results in the spatial extent of cities expanding both horizontally and vertically. The climatic response of urban areas differs greatly to rural areas exposed to the same environmental conditions, with urban temperatures generally being higher, particularly in the late afternoon and evening. Coupled with the upward trend in global temperatures, urban heating can be classified as an atmospheric hazard that affects a high proportion of the population in some countries, which needs to be addressed through local and national government planning strategies. This study presents preliminary findings from a city scale urban climate model developed using the fast climate modelling tool ADMS-Urban for the city of Kuala Lumpur, Malaysia, which is known to suffer from substantial urban heating, and discusses the extent and intensity of the urban heat island in light of existing literature based on field measurements. The model has been configured to use surface characteristic data derived from land-use data as input, and through comparison with temperature variations derived from satellite imagery, the model is seen to clearly capture the spatial variation of temperature over the domain. The urban heat island intensities predicted by the model are comparable to the values reported in literature. This study also demonstrates the strong relationship between temperatures and wind speed, which is generally much lower in tropical Kuala Lumpur compared to mid-latitudes, and the urban heat island intensity and nocturnal cooling. The future modelling studies should account for anthropogenic heating, for instance, from air conditioning units and traffic, which are important sources of heat in tropical areas, and expand more on building materials and morphology for a thorough appraisal of urban heating in Kuala Lumpur.

Land Use/Land Cover Changes and the Relationship with Land Surface Temperature Using Landsat and MODIS Imageries in Cameron Highlands, Malaysia

“…Various studies of Asian cities comparable in size and density have observed an excess of anthropogenic heating as high as 1.5 • C [21,48,[63][64][65]. A study by Wang et al [66] conducted in Kuala Lumpur states that "air temperature is a good comparison against satellite-based data obtained temperatures, however, they do not reflect on the 'true' temperate climate of a surrounding area with a multitude of external implications such as wind speed, time, body induced heat radiation as well as heat created from vehicles". This statement is also supported by the study of Kong et al [45], in which air temperature data also showed signs of outliers, mostly consisting of highs during the summer months of April to June, with estimated values of 0.3-0.5 • C. This could be a case of radiative heat being trapped amongst buildings or another case of climate-induced change as a result of increased influx into the region.…”

Outdoor Thermal Comfort and Building Energy Use Potential in Different Land-Use Areas in Tropical Cities: Case of Kuala Lumpur

“…ADMS-Urban is a fast local-scale urban climate modelling tool, widely used to calculate the spatiotemporal variation of neighborhood or city scale urban temperatures and dispersion modelling. The parametrization and land-use input data used in the ADMS modelling of Kuala Lumpur to study the urban temperature perturbations was previously described in [58]. In addition to this, in this study a detailed urban canopy model with 200 m resolution was developed to quantify the roughness length in terms of building density and geometry [59] to model hourly wind speeds at 10 m height.…”

Analysis of Urban Morphological Effect on the Microclimate of the Urban Residential Area of Kampung Baru in Kuala Lumpur Using a Geospatial Approach

“…Moreover, previous studies on UHI in Kuala Lumpur have reported that UHI has major effects on thermal comfort, human health, pollution, societal economy, and meteorology and climate. Policymakers, local governments, and engineers must therefore consider the factors that contribute to the UHI phenomenon before designing and developing new urban areas [16][17][18][19]. Nevertheless, there has been no detailed study to investigate the microclimate of Kampung Baru in terms of weather patterns and effects of UHI.…”

“…Moreover, it is located less than 5 km from the city center where high-rise buildings such as the Petronas Twin Tower and the Kuala Lumpur Tower (KL Tower) dominate the city's skyline. The development of an urban area should prioritize the mitigation of UHI effects [16][17][18][19][20]. Specific considerations are investigated for determining UHI effects from urban morphological characteristics.…”