Spatiotemporal interaction between urban heat island and urban-construction indicators on the block scale in autumn in a humid and hot climate

Abstract

Urban heat islands (UHI) have strong spatiotemporal variations. Despite surface UHIs (SUHIs) with fine spatial distribution, UHIs have many advantages, more continuous temporal patterns, more relevant to people's feelings, and better thermal interaction between adjacent areas. Furthermore, the incomplete overlap between SUHI and UHI patterns within a city likely causes inconsistent research results and even influences urban-planning decisions. This paper conducted a six-day gridding field measurement of UHI intensity (UHII) in Guangzhou in autumn to comprehend its spatiotemporal pattern, to determine its response radius with urban-construction indicators and the accordingly magnitude of their interaction, and to recommend critical urban-construction indicators on a block scale. Results show that the hourly UHII at a given period cannot reflect the daily UHII. The optimal interpretation radius of UHII was up to 100 m, thus implying strong interactions within these buffer zones. The larger the block scale, the more consideration should be given to the influence of configuration of the internal landscape on UHII; the smaller the block scale, the more consideration should be on the surrounding landscape. Based on regression analysis, concrete coverage and tree coverage were the most vital urban-construction indicators on the block scale, followed by sky view factor, site coverage, and waterbody coverage.