Impact of Carbon Sinks on Urban Heat Island Effects : Assessment Using Satellite Data in Water Scarce Region of the Thesis

Abstract: Urbanization modifies the thermal characteristics of the land and makes way for a succession of transformations in the urban environmental system. This phenomenon, known as Urban Heat Island (UHI), is characterized by elevated temperatures in urban areas that negatively impact on the quality of life and environment in urban areas including, increased emissions of Green House Gases (GHGs) and rising energy consumption. These impacts add to global climate change and thus, mitigating UHI is essential to mitigating global climate change. One GHG, Carbon Dioxide (CO2), accounts for about half of the Earth’s anthropogenic GHG emissions. Terrestrial ecosystems can act as Carbon sinks (C sinks), i.e. natural vegetation reservoirs that absorb more C than they release. Thus, C sinks play an essential and critical function in lowering CO2. Furthermore, providing appropriate C sinks at both the building and urban scales can decrease UHI and contribute to reduction in energy consumption. This study used Landsat 8 imagery of the site, Al Bayt Stadium in Qatar, to investigate the effects of surface UHI by computing the Land Surface Temperature (LST) difference of the site---pre- and post-construction, as well as examine the correlation between natural vegetation abundance and temperature in ten locations within the site’s vicinity. Results show that minimum, maximum and mean LST of the case study area (2014 vs. 2020) decreased 2.80 oC, 5.5 oC and 2.3 oC, respectively, as well as a decreasing trend in the LST as a function of increasing C Sinks. These results demonstrate the importance of introducing C sinks to lower LST and mitigate UHI. Mitigating UHI also has a direct effect on Energy Consumption Balance (ECB). This equilibrium is achieved not only through the introduction of C sinks, but balancing C sinks with high albedo materials and natural ventilation.  Thus, this study also investigated the site’s various design aspects (e.g. cooling technology, structure and surface albedo materials, landscaping) and found that Al Bayt Stadium’s design successfully incorporates strategies to reduce energy consumption at both the urban (macro) and building (micro) scales.