Estimating spatial effects of anthropogenic heat emissions upon the urban thermal environment in an urban agglomeration area in East China

Abstract

Various anthropogenic heat (AH) emissions that are mainly confined to urban areas have already changed the variability of urban climate. As a major human impact on our global environment, there is a lack of understanding regarding quantification, temporal, and geospatial impacts of AH over large areas. In this study, by using various remote sensing and socioeconomic data, we firstly attempt to quantify the spatial patterns of AH in the Yangtze River Delta (YRD) agglomeration of East China. After that, we organized the agglomeration area into four types (city ​​centre, developed areas, suburbs, and rural areas). We then analyse the temporal and spatial impacts on the urban thermal environment. The results show that: (1) The total amount of AH emissions in the YRD reached 8.19 × 1018 J per year, with an uneven spatial distribution. There are profound differences in AH total and heat components for each city due to different socioeconomic backgrounds. (2) The correlation between AH distribution and the thermal environment are examined, and higher correlations are observed in the cities that generated large AH emissions. Seasonally, higher correlation exists in summer, while it is lower in winter. (3) The correlation between AH flux types and the thermal environment also varied for different human activity types. In the city centre, the thermal environment is related closely to AH fluxes from vehicular traffic; in developed areas there is a close relation to AH fluxes from life and tertiary industry; and in the suburbs it relates closely to AH emissions by industrial activity. Finally, we discussed the important regulatory effects of precipitation, vegetation and water bodies on AH fluxes. Overall, this study proved that the environmental impact of AH sections included herein clearly varies temporally and spatially, and suggest specific strategies for reducing the heat risk due to further urbanization.