Analysis of microclimatic diversity and outdoor thermal comfort perceptions in the tropical megacity Dhaka, Bangladesh

Date

2015-11-11

Advisors

Journal Title

Journal ISSN

ISSN

0360-1323

Volume Title

Publisher

Elsevier

Type

Article

Peer reviewed

Yes

Abstract

The study has observed microclimatic conditions in residential, commercial and educational areas in Dhaka city. Comfort surveys were carried out along with microclimatic measurements. Findings suggest, urban forms that are more variable with irregular plot sizes and building heights, mostly in traditional areas, have positive responses with respect to the synoptic climate, while planned areas with uniform plot sizes and height, shows a tendency to develop daytime urban heat island effect. An eastewest orientated street in a formal residential area was found to be 1 Ce3.8 C warmer than a street in a traditional residential area in the same orientation. It is apparent that the differences are directly linked to the specific geometric pattern of the areas and can be defined by the parameters like uniformity versus diversity and compactness versus openness. Uniform heights, equal building separation and plot sizes can lead to harsher urban microclimate, while variety in these may foster positive changes. Lack of such variety can even affect compact urban areas. This is also evident from the analysis of pedestrian's responses in the case-study areas. Pedestrians in the formal planned areas or less diverse traditional areas were found to be less comfortable than those in the more variable areas. A statistical analysis of climatic variables and thermal sensation showed moderately strong and significant correlations. These reveal that urban geometry and the resultant climatic variables may not be the only, but one of the most important factors for governing the outdoor thermal comfort sensation in a tropical climate.

Description

The Publisher's final version can be found by following the DOI link.

Keywords

Urban microclimate, Urban geometry, Outdoor thermal comfort, Tropical hot-humid climate

Citation

Sharmin, T., Steemers, K. and Matzarakis, A. (2015) Analysis of microclimatic diversity and outdoor thermal comfort perceptions in the tropical megacity Dhaka, Bangladesh. Building and Environment, 94 , pp.734–750.

Rights

Research Institute

Institute of Architecture