Green infrastructure measures to mitigate urban heat island effect: a case of Hyderabad city

Abstract

Micro-climate changes due to urbanization are epitomized by the urban heat island (UHI), which is characterized by temperature differences between urban and rural areas. Unprecedented growth has resulted in the removal of vegetation, leading to loss of green land cover. It has also altered the change in land use and land cover which has aggravated the Urban Heat Island (UHI) phenomenon. Hyderabad city in southern India has been selected as a case study for the effect of urbanization on the local climate of the cities. The possible factors responsible for UHI effect in Hyderabad city was identified with an empirical support to this effect. This research paper tries to develop an original conceptual framework for the mapping of the formation of urban heat islands. The two mediators (write the names of the 2 mediators) are the focuses of this dissertation. First is to assess and analyze the UHI factors of the selected case study area where two types of data were used in this study: periodical air temperature data, and satellite image of Hyderabad city. Analysis of temperature data and land use showed significant changes in the micro climate of the city over the period of time. Second is the satellite image, used to generate a map of NDVI for the city, which in turn was used to generate the land surface temperature map of Hyderabad city. With the help of LST map it was found that, there were indications of temperature variations from the thermal reflections of each land use and land cover of the city. The greatest proliferation of hot spots is observed over some industrial development and mixed land use areas, where the UHI are expected to develop, while the cooler areas comprise green zones or water bodies. Based on population density and time series analysis of pollution for recent years showed intensification of UHI, in institutional, commercial, some parts of old city and industrial areas. A highly air polluted area, with moderate population density having mixed land use, and the scope for the future expansion, has been delineated for conducting the pilot study to propose measures to mitigate the UHI effect. The results demonstrate the possibility to reduce temperatures in residential and urban areas through judicious siting of green areas. As an outcome of the Green infrastructure measures to mitigate Urban Heat island effect: A case of Hyderabad city analysis, mitigating measures for UHI effect including green infrastructure and policy level guidelines are proposed. Since, Hyderabad city doesn't have any regulations for FSI.