MITIGATION OF URBAN HEAT ISLAND EFFECT WITH SMALL-SCALE PARKS—AN EMPIRICAL STUDY ON COMMUNITY PARKS IN NANJING, JIANGSU PROVINCE

Abstract

Cities have suffered from urban heat island (UHI) effect due to rapid urbanization, which can be effectively adjusted by urban green space. Taking the community parks in central area of Nanjing, Jiangsu Province as an example, this paper explored the size and shape of smallscale parks to mitigate the UHI effect. Land surface temperature was retrieved from Landsat 8-OLI remote-sensing image of 2019. The 52 studied community parks were identified with ArcGIS 10.4, and classified by kernel building density. The threshold-size and optimal shape of community parks to mitigate UHI effect were then discussed. The results showed that 1) with the increase of buffer ring distance around the community parks, the cooling intensity decreased and the cooling extent were mostly less than 180 m; 2) the area, shape, and the NDVI of the parks were important factors affecting the cooling intensity; 3) the cooling intensity of community parks under a high kernel building density was better, with a higher threshold-size (0.848 hm2) than that of the low ones (0.384 hm2); and 4) the optimal cooling intensity would occur when the park in a shape of circle or square. In conclusion, it is suggested that small green space should be planned in the areas under a high building density. Through renewal design and refined management measures in the urban green space system planning, giving full play to the ecological benefits of urban green spaces in mitigating the local UHI effect can also be expected.

Keywords

Community Park / Nature-Based Solutions / Urban Heat Island Effect / Microclimate Adjustment / Empirical Study

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2020 Higher Education Press