Chandana Mitra, Auburn University, Auburn, AL, USA

Rupsa Bhowmick, Jadavpur University, Kolkata, India

Devendra Pradhan, Indian Meteorological Department, Kolkata, India

Presentation Title: Urban heat island intensity of Kolkata city and methods to ameliorate its impact




Located in eastern India, Kolkata city is one of the four largest megalopolises in India, with a population of over 15 million (Census of India, 2011). To contain this huge populace, the city has been going through major land-use/cover changes in the recent decades. The eastern part of the city is seeing major transformation, where the wetlands are being replaced by built-up surfaces. This transformation is bound to have some impact on the microclimate of the city, especially the temperature patterns. Thus, it is important to quantify the urban heat island (UHI) intensity across the length and breadth of Kolkata to see how temperature patterns are changing. A three-month pilot study (during April, May and June, the hottest months of the year) was conducted to measure the UHI magnitude and intensity.

Key Lessons Learned

  • Studying the tropics is important, i.e., heatwaves in this area are researched much less when compared to temperate regions and subtropics, despite their prevalence.
  • It will be important to focus UHI research on small to medium-sized cities, as they will grow the fastest into the future.  Research cannot easily be replicated and applied to all parts of the world, as many local and regional variations and challenges exist (e.g., regarding placement and ‘disappearance’ of temperature recording sensors).
  • Ultimately, human welfare is the greatest concern, so the communication of basic knowledge to city residents is key.
  • Urban approaches that are tailor-made for adaptation and mitigation (to some extent) are challenging, but must be undertaken and should involve local experts.

 Policy/Practice Implications of Research

  • Increases in urban flooding and heat waves will impact human health and infrastructure in high-density cities of the developing world. Urban precipitation and urban heat island research will help build policies for risk reduction and resilience.
  • If the gap between urban climate researchers and government officials and planners can be bridged, this research will aid in the development of more sustainable and resilient urban environments.

Knowledge Gaps and Needs

  • A lack of readily available and continuous precipitation and temperature data, especially in developing countries, which hampers good research.
  • More research on cities globally to contrast and compare outcomes, which will help inform future planning efforts.
  • The use of newer satellite-derived datasets for land cover, precipitation, temperature and aerosols to conduct robust and extensive research on the urban environment.
  • Lack of communication between the academicians and practitioners at the local city level.