MOTORIZED TRANSPORTATION AND THE UHI EFFECT IN DOHA: THE IMPACT OF TRAFFIC ON THE HEAT ISLAND EFFECT

Abstract

Doha is a car-oriented city with rapid urban growth and development; one result of this is the replacement of large areas of the local terrain’s natural surface with asphalt paving and other building materials. Therefore, as the city and surrounding areas have developed, the local landscape has undergone profound changes. Buildings, roads, and other infrastructure have replaced open land and areas where vegetation once grew. Surfaces that were once permeable and moist have become impermeable and dry. At the same time, Doha has been experiencing rising temperatures associated with the growth of the urban land surface, a change that continues over time as new development occurs. As Doha becomes an increasingly car-oriented city, emissions from cars and asphalt, accompanied by solar radiation, are absorbed by the materials of the local buildings. The net result of all of this is a microclimate that has a negative impact on the environment. Against this background, this study explores the impact of the city’s transportation system on its environment. This thesis also explores possible solutions for enhancing the quality of development by reducing the impact of motorized vehicles (most notably cars) on the Urban Heat Island (UHI) effect. The first question that will be addressed -- through an examination of the road network and vehicular movement in Doha in relation to the UHI effect -- can be posed as follows: Does the city’s traffic contribute to the UHI phenomenon? Furthermore, the use the Remote sensing (ENVI) program and Geographic Information System (GIS) data permits an examination of the relationship between (a) road surface temperature and its outgoing long wave radiation in Doha and (b) traffic volume. The results of this analysis reveal that automobile traffic is a key contributor to heat formation in Doha, especially in the context of traffic jams. The paved surface materials characteristic of urban roads emit a great deal of heat into the city, in part because they cover such a large fraction of the urban surface. It is also found that part of the UHI effect can be attributed to the dark pavements that are often used on streets and parking lots; these also contribute to the heat and emissions generated by cars and traffic jams, in turn worsening the heat island effect and accompanying pollution. This thesis will conclude with recommendations for achieving sustainable development, with the ultimate goal of improving the quality of life and reducing excessive pressure on the environment in Doha.