Strategies to Mitigate the Urban Heat Island Effect.

Urban Vegetation

Brief: Shading, Evapotranspiration through vegetation makes surfaces cooler. A mixture of taller trees with shrubs and grass as seen in Hyde park (Sydney) make landscapes cooler more than built up areas. Well irrigated areas can get even cooler because of presence of moisture. Tree canopy can be increased by planting shade trees in footpaths, forecourts and street medians as well as increasing the number of parks.

Benefits:

Effective storm water management

Better air quality

Biodiversity, Reduces ambient temperatures, Indirectly saves energy

Improves urban aesthetics

Cool Surfaces

Brief: Materials tend to store heat in urban area. Materials that have higher reflective properties, more permeability and increased emittance are materials that can keep their surroundings cooler. For example, roof surface with a white coating benefit by radiating away up to 75% of solar energy. Australian cities are made up of 20% of roof surfaces. They are more exposed to sunlight and thus is necessary to use cooling materials for them.

Benefits:

Indoor thermal comfort,

Cooler indoor environments

Lower dependency on appliances

Increased outdoor thermal comfort

Higher urban air quality

Water

Brief:

When water evaporates form a paved surface this results in a decrease of air temperature. Increase in evaporative cooling using passive or active strategies helps in reducing temperatures. Mayor Muller Plaza (Germany) has water features that make it an attractive community space as the water uses the heat for evaporation benefiting the surroundings by lowering temperatures.

Benefits:

Absorb Ambient heat

Improves urban aesthetics

Increased outdoor thermal comfort

Higher urban air quality

Green Roofs

Brief: Green roofs help in removing heat from the air and to reduce temperature of the roof surface and surrounding air. This prevents heat from being transferred to the lower floor as well. For example in Camelview Village in United States, the roof is stepped and has different vegetation and provision for community spaces on the roof. The structure uses stormwater and prevents residents from effects of the dessert sun.

Benefits:

Effective storm water management

Better air quality

Reduces ambient temperatures, Indirectly saves energy

Improves health and comfort of users of the building

Green Walls

Brief: Living green walls are natural air-filters, creating a cleaner, improving the comfort levels of the indoor spaces of the building. Vertical landscaping can reduce building envelope surface temperatures between 5°C and 15°C. For example in One Central Park green walls are used as a strategy to reduce indoor temperatures.

Benefits:

Better air quality

Biodiversity, Reduces ambient temperatures, Indirectly saves energy

Improves health and comfort of users of the building

Increased outdoor thermal comfort

Improves urban aesthetics

Need for Strategies

The above strategies overall help to combat heat which is specifically needed for hotter climates and rising temperatures. A sustainable action plan is needed to fully understand these strategies and implement them as per the sites requirements. the major goals include:

Increase in Urban Vegetation

Reduce Carbon Emission

Improve Health and Well-being

Major Problems Addressed

Implementation and Monitoring