Modelling urban cooling island impact of green space and water bodies on surface urban heat island in a continuously developing urban area

摘要

Urban areas are most affected by the adverse environmental impacts such as urban microclimate change in the form of urban heat island effect (UHI) which results into the urban health degradation. For this concern, mitigation of UHI gains more attention to the urban researchers. The spatial pattern of green spaces have an important impact on urban heat island mitigation also existing green spaces and water bodies can play an important role to reduce the urban heat island intensity. This study tries to find out the changing behaviour of land surface temperature in respect to change in land use types. This Study found a significant relationship between green space composition and configuration on mitigating increasing temperature of the whole study area And also identify the impact of individual green space and water body configuration in mitigating urban heat island effect. To assess the impact of green spaces and water bodies on Surface Urban Heat Island (SUHI), land use land cover map is prepared using unsupervised classification method, NDVI and NDWI and land surface temperature is also calculated. Extraction of land surface temperature values is performed and impact of green space and water body is assessed using different graphs. Results of this study suggest that green space is more effective in SUHI mitigation than the water bodies. Green space can control 1?°C temperature minimization for a 150–180?m distance from green space boundary and elongated shaped green space can control 1?°C temperature drop for more areas than the circular green spaces and irregular shaped green spaces and water bodies play more important role in mitigating SUHI effect than regular shaped green spaces and water bodies. Results of this study can be used for future urban planning for minimizing SUHI impact for certain areas by considering the size and the shape of the plant green spaces and water bodies for adopting increasing SUHI impact of the highly urbanized areas.