Role of urban morphology in enhancing the outdoor thermal comfort: A case of Mumbai
Kritika Vidyashankar1, Srushti Rahigude1*, Lilly Rose Amirtham2
1: CEPT University, Ahmedabad, India;
2: School of Planning and Architecture, Vijayawada, India
DOI: 10.62744/CATE.45273.1134-140-150
Email: srushti.ud@gmail.com
Abstract:
In recent years, the city of Mumbai has been experiencing the pressing challenge of urban heat islands, affecting the thermal comfort of its high-density urban environment, impacting both air and surface temperatures. The Intergovernmental Panel on Climate Change (IPCC) projected that climate change would adversely affect 27 million people in Mumbai (6th assessment report). Understanding the intricate relationship between the built environment and its influence on microclimates and thermal comfort was imperative for creating climate-sensitive designs. This paper investigated the role of urban morphology in improving the thermal comfort of a typical neighborhood in Mumbai. The analysis was based on simulations conducted using ENVI-met, a 3D urban climate modeling tool. The research aimed to comprehend how open spaces, aspect ratio, setbacks, and plot boundary conditions within the neighborhood affected outdoor thermal comfort. The objective was to underscore the significance of urban designers and planners in assessing the impact of built environments on microclimates and leveraging microclimatic insights for the design of public spaces. Air temperature, relative humidity, wind speed, and mean radiant temperature were measured at 15 locations within the neighborhood, Matunga east, and its primary street in February 2023. The recorded data were used to validate the Envi-Met model . Two distinct scales were analyzed: neighborhood-level and plot-level iterations. Neighborhood-level iterations focused on block-level modifications, while plot-level iterations examined street and boundary conditions. Each iteration was evaluated using EnviMet to assess changes in thermal conditions relative to the current site conditions (Base case). The analyses were conducted for the critical summer month (May). The study ultimately revealed that the introduction of road networks in prevailing wind directions and the incorporation of green open spaces within the urban fabric could reduce overall heat stress duration from 12 hours to 6 hours. Smaller-scale interventions, such as 50% porous pavements and strategically placed trees, also yielded positive outcomes. This research
aspired to provide urban planners with a comprehensive framework that integrated outdoor thermal comfort as a pivotal aspect in the design of future urban landscapes.
Keywords: Outdoor Thermal Comfort, Climate Resilience, Urban Morphology, EnviMet