by S Hamada, T Ohta
Urban Forestry & Urban Greening, 9(1):15-242010
Previous studies have looked at the cooling effect of urban green areas on surrounding urban areas. This study goes further by examining the seasonal variations in air temperature between urban areas and urban green areas. Researchers were primarily concerned with the range of the cooling effect and how vegetation cover influenced air temperature. The study found significant associations between temperature and forest-cover ratio. Significant seasonal differences were also observed. The largest differences in temperature between urban and green areas was observed during the summer, while little difference was observed in winter. This result was attributed to the leaf fall from the deciduous trees, and both radiation and evapotranspiration were found to contribute to the cooling effect. Furthermore, the cooling effect also showed daily variations. During the summer the difference was greater during the day than at night; and the opposite during winter months. Finally, the results showed that the cooling effect reached no more than 500m at any time during the study period. Overall, findings from the study demonstrate the benefits of dispersing green areas throughout an urban environment.