Assessing the Heat Vulnerability of Different Local Climate Zones in the Old Areas of a Chinese Megacity

Abstract

Frequent and extreme heat waves have strongly influenced the sustainable development of cities and resulted in a higher level of mortality in residents. Using the Local Climate Zone (LCZ) classification scheme, combined with the factors of land surface temperature (LST), building age (BA), and housing price (HP), and the normalized values of which represent heat exposure, sensitivity, and adaptability, respectively, this paper investigates a practical method for assessing the heat vulnerability of different LCZ classes in the old areas of a Chinese megacity, taking the Yuzhong district of Chongqing city as a case study. The results reveal that the distribution of LCZ classes in this study area exhibits a typical circle-layer distribution pattern from the city center to the suburbs. Heavy industry areas are the most vulnerable, with the highest exposure to heat waves, the oldest building age and the lowest housing price. Compact class areas (compact high-rise, compact mid-rise and compact low-rise) are usually more vulnerable than open class areas (open high-rise, open mid-rise, and open low-rise) and low-rise buildings are always more susceptible to heat waves than mid-rise and high-rise buildings. The methods and findings can help us to better understand the comprehensive and space-time action rules of heat vulnerability, thereby inspiring scientific and rational urban planning strategies to mitigate or adapt to urban heat weaves towards the sustainable development of cities and society.2 of 15 an extreme heat wave caused more than 70,000 deaths in Europe [13], and the extreme heat waves in the United States from 1999 to 2010 resulted in 7415 deaths, more than the total number of deaths from typhoons, floods, earthquakes and other disasters during the same period [14].Therefore, it is urgent to assess the vulnerability of areas subject to urban heat waves and provide corresponding mitigation or adaptation strategies based on it. This has become a hot topic in the study of healthy cities. Heat vulnerability refers to the degree of vulnerability or inability of urban residents to cope with the adverse effects of heat waves, and it is typically composed of three types of indicators: exposure, sensitivity and adaptability [15,16]. In this context, "exposure" refers to the proximity of the location of a group or individual to the hazards of heat waves, which reflect the characteristics, intensity and frequency of the heat waves suffered by urban residents [17]. The most widely used indicators for evaluating heat exposure include the urban thermal environment (e.g., air temperature, land surface temperature and urban heat island intensity) [18,19] and urban spatial parameters (e.g., sky view factor and impervious surface fraction) [20]. In this context, "sensitivity" refers to the degree to which urban residents change their physiological structure in the face of the external interference of extreme heat waves. Widely used evaluation indicators include the proportion of vulnerable groups, such as the elderly, infants ...

Mapping Local Climate Zones: A Bibliometric Meta-Analysis and Systematic Review

“…(2) For the grid unit, the appropriate grid size can be determined by the following strategies: (i) Based on empirical knowledge. This method has been widely used to determine the grid size (Agathangelidis et al, 2019;Cai et al, 2019;Geletič et al, 2019Mitraka et al, 2015;Shi et al, 2018;Wang et al, 2018b;Yang et al, 2020c). For example, Geletic & chose 100 m as the spatial unit size for three medium-sized cities (Brno, Hradec Králové, and Olomouc) in Czech Republic, because on this scale the physical properties of the environment significantly affect local air temperature.…”

“…The direct way to determine LCZ classes is to match the calculated values of LCZ parameters with their reference ranges. This method has been most widely used to distinguish LCZs based on the LCZ parameters provided by Stewart & Oke (2012) or custom parameters (Agathangelidis et al, 2019;Bartesaghi Koc et al, 2018, 2017Cai et al, 2019;Emmanuel & Loconsole, 2015;Jin et al, 2020;Leconte et al, 2017Leconte et al, , 2015Mandelmilch et al, 2020;Mitraka et al, 2015;Nassar et al, 2016;Ndetto & Matzarakis, 2015;Perera & Emmanuel, 2018;Shi et al, 2018;Thomas et al, 2014;Villadiego & Velay-Dabat, 2014;Wang et al, 2018b;Zheng et al, 2018). In addition, some studies have used other methods to determine LCZ types, such as the score assignment method (Lelovics et al, 2014;Unger et al, 2014), the decision-making algorithm (Chen et al, 2020b;Quan, 2019;Zhao et al, 2019a), the multi-dimensional linear interpolation method (Quan et al, 2017), the Naive Bayes algorithm (Hammerberg et al, 2018), the random forest algorithm (Hu et al, 2019), and the k-means method (Hidalgo et al, 2019;Kwok et al, 2019;Zhan et al, 2018).…”

A Statistical Procedure for Analyzing the Behavior of Air Pollutants during Temperature Extreme Events: The Case Study of Emilia-Romagna Region (Northern Italy)

“…In the last years, the scientific research linked to human health and wellbeing of populations in urban and industrialized areas mainly focused on two issues: climate change and air quality [1][2][3][4][5][6][7][8][9][10]. Climate change affects human wellbeing through many related events: increased frequency and intensity of heat waves and cold waves, changing precipitation intensity, and increased devastating weather events, such as hurricanes, tornadoes, floods and droughts, cold-related mortality, and heat-related mortality [11][12][13][14][15][16][17].…”

Urban Spatial Patterns and Heat Exposure in the Mediterranean City of Tel Aviv

“…The LCZ classification has become a methodological tool for the analysis of UHI and the causes of UHI intensity [5,19,20]. Thus, the LCZ classification scheme can be used as a basis for heat exposure analysis in the urban area [21,22]. Currently, the World Urban Database and Access Portal (WUDAPT) is the most widely used method for LCZ mapping of cities around the world.…”