Role of Vegetation in the Microclimatic Conditions: Formulation of Urban Heat Islands

Cities, or urban areas face many challenges, be it the pressure on infrastructure or continuous sprawl, but the worst of the challenges are the impacts of global warming on cities. Urban areas, due to scarcity of mitigation efforts, face the most significant climate change. One such impact is the formation of urban heat islands within the cities. Not only are there urban heat islands within the microclimate of a city, but also city as an entity, in general becomes a heat island when seen in cohesion with the adjoining peri- urban and rural areas. The cause of this phenomenon itself is the way to mitigate it. The surface of an urban area and a rural area are significantly different, where rural areas have more of vegetation and water bodies, which serves as heat sinks, urban areas in contrast, lack these surfaces to an extent that within the same city boundary one can witness a varied range of temperature differences. Even the increasing pollution in cities, adds to the UHI effect. The automobile driven societies, are laying down roads every day, but not sensitive to the fact the vegetation along the roads is an important feature of the network itself. During summers, we immediately feel the heat on the roads and witness the mirage effect. So on some levels, within a neighbourhood, with buildings, parks, and roads, roads by default would have a higher temperature due to the vehicles, and surface quality of the road. This paper would first identify the difference in the surfaces in rural, peri-urban, and urban areas with respect to their impacts on the environment. With the help of suitable examples this difference would be established in connection to formation of urban heat islands. Also case studies of how this urban heat island has been mitigated in cities and what role has vegetation, water bodies and urban open spaces have played in the same.