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Strategies to Mitigate the Urban Heat Island Effect. Urban Vegetation Brief: Shading, Evapotranspiration through vegetation
Fig.13. Hyde Park Walkway, Source: D’cruz
Cool Surfaces
Fig.14. Cool roofs, Source: Dezeen
Water
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 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 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
Fig.15. Mayor Muller Plaza source: Mai, POLA