Analyzing Urban Heat Islands with Land Use Changes

Edmonton

Climate Change

Urban Heat Island (UHI) refers to the “island” of warmer temperature in an urban area compared to its rural surroundings. UHI occurs in almost all urban areas as the built surfaces absorb and store a large quantity of solar radiation. Its effect is closely linked to elevated emissions of air pollutants and greenhouse gases (GHG), increased energy consumption, and leads to compromised human health.

Thus, understanding UHI effect is essential for long-term planning of any city including Winter Cities such as Edmonton, particularly under changing climate and increasing built surface areas. The built-up area in Edmonton increased multiple folds during the four decades.

However, no study has focused on Edmonton’s temporal UHI changes and intra-urban UHI patterns. This study will address these knowledge gaps by answering the following four questions:

  1. Was there a significant UHI change across the city of Edmonton over the last two decades?
  2. Does UHI vary across neighbourhoods within the city?
  3. What factors affect UHI at the neighborhood level? and
  4. What mitigation measures could minimize possible UHI-induced impacts?

Researchers Dr. Sandeep Agrawal, Dr. Nilusha Welegedara, and Dr. Neelakshi Joshi draw on two broad data streams using a mixed-methods approach:

  1. They will analyze the medium spatial resolution multi-spectral satellite imagery to generate neighbourhood UHI and land use maps. They will gather station-based weather data at different locations in or close to Edmonton to validate the satellite derived UHI maps.
  2. They will use relevant City documents, field observations, and residents’ feedback to understand possible contributing factors such as land uses, population density, vegetation canopies, and water bodies within different neighbourhoods in the city.

The answer to these questions will help policy-makers to develop heat mitigation and adaptation strategies for existing neighbourhoods. It will inform the planning and design of new neighbourhoods, so they elicit minimum UHI effects.