This page has only limited features, please log in for full access.
While previous studies revealed that urban form optimization could alleviate the urban heat island (UHI) effect, empirical studies have often documented paradoxical conclusions on the impacts of urban form on land surface temperature (LST). To examine whether the effect of urban form on LST varies across cities, data on 266 Chinese cities are used to conduct OLS regression analyses. These cities are divided into three groups: cities in different climatic zones, cities with different urban area sizes, and cities with different industrial structures. The results show that, at the national scale, LST (in summer daytime) is negatively correlated with compactness, boundary complexity, and urban shape but positively correlated with contiguity. However, these effects are heterogeneous across cities. Specifically, contiguity exhibits a relatively stronger influence on LST in cities located in Temperate and Warm-temperate zones. Compactness and urban shape significantly impact LST in small-sized, medium-sized cities and megacities, while the effects are insignificant in large-sized cities. Polycentric shape for industrial cities surprisingly elevates LST. Several practical policy implications for urban planning under different scenarios are proposed to ameliorate the UHI effect. This study could contribute to the alleviation of the UHI effect in regions whose climate characteristics and development levels are similar to those of China.
Hangying Su; Guifeng Han; Lin Li; Hongqiao Qin. The impact of macro-scale urban form on land surface temperature: An empirical study based on climate zone, urban size and industrial structure in China. Sustainable Cities and Society 2021, 74, 103217 .
AMA StyleHangying Su, Guifeng Han, Lin Li, Hongqiao Qin. The impact of macro-scale urban form on land surface temperature: An empirical study based on climate zone, urban size and industrial structure in China. Sustainable Cities and Society. 2021; 74 ():103217.
Chicago/Turabian StyleHangying Su; Guifeng Han; Lin Li; Hongqiao Qin. 2021. "The impact of macro-scale urban form on land surface temperature: An empirical study based on climate zone, urban size and industrial structure in China." Sustainable Cities and Society 74, no. : 103217.
In recent years, frequent heat waves have severely reduced the quality of human settlements in big cities. To reveal the influence of urban spatial form on land surface temperature (LST) in mountainous cities, Chongqing city in China was selected as a case study. The quantitative relationships between five urban spatial form factors and LST are analyzed, such as sky view factor (SVF), urban surface roughness (USR), road surface area density (RSD), building density (BD) and floor area ratio (FAR). The results showed that the spatial scale influence their correlations. Most urban spatial form factors have a significant positive relationship with LST, besides FAR. The various regression results have also shown that spatial regression models (Spatial lag model, Spatial error model and General spatial model) are working better than OLS model, due to the reason that some of the urban spatial form factors have spatial spillover and spatial heterogeneity effect. Besides the spatial effect, the unique topography of mountainous city also has an impact on LST, such as the slope, aspect and underlying surface. Therefore, the planners should consider those differences in mountainous cities, and using different methods to mitigate UHI and making the city cope with climate change.
Jianming Guo; Guifeng Han; Yusi Xie; Zhi Cai; Yifan Zhao. Exploring the relationships between urban spatial form factors and land surface temperature in mountainous area: A case study in Chongqing city, China. Sustainable Cities and Society 2020, 61, 102286 .
AMA StyleJianming Guo, Guifeng Han, Yusi Xie, Zhi Cai, Yifan Zhao. Exploring the relationships between urban spatial form factors and land surface temperature in mountainous area: A case study in Chongqing city, China. Sustainable Cities and Society. 2020; 61 ():102286.
Chicago/Turabian StyleJianming Guo; Guifeng Han; Yusi Xie; Zhi Cai; Yifan Zhao. 2020. "Exploring the relationships between urban spatial form factors and land surface temperature in mountainous area: A case study in Chongqing city, China." Sustainable Cities and Society 61, no. : 102286.
Social media is an important tool for disaster prevention and management. To reveal the public responses to disasters on social media in the context of East Asian culture, an urban flood disaster event that occurred in Wuhan City, China, in the summer of 2016 was selected as a case. Data were collected from Sina-Weibo, which is the earliest and most popular social media platform in China. We categorized a total of 17047 messages into four types, analyzed the Pearson correlation between information dissemination and precipitation, and identified the important accounts and their messages in the social networks by visualized analysis. The results show that there is a one-day lag between participation and public response. Message dissemination has a steeply downward trend over time, that is, a long tail effect. Information disseminates quickly within two hours, and then dissemination declines after four hours, with opinion messages disseminating faster than other types of messages. Famous news organizations and several celebrities play a leading role in social networks. In general, the participation of Chinese netizens in disaster events is lower than that of people in Western countries, and social media is not yet used as a tool for disaster response.
Xiaoxue Cheng; Guifeng Han; Yifan Zhao; Lin Li. Evaluating Social Media Response to Urban Flood Disaster: Case Study on an East Asian City (Wuhan, China). Sustainability 2019, 11, 5330 .
AMA StyleXiaoxue Cheng, Guifeng Han, Yifan Zhao, Lin Li. Evaluating Social Media Response to Urban Flood Disaster: Case Study on an East Asian City (Wuhan, China). Sustainability. 2019; 11 (19):5330.
Chicago/Turabian StyleXiaoxue Cheng; Guifeng Han; Yifan Zhao; Lin Li. 2019. "Evaluating Social Media Response to Urban Flood Disaster: Case Study on an East Asian City (Wuhan, China)." Sustainability 11, no. 19: 5330.
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.
Zhi Cai; Yan Tang; Kai Chen; Guifeng Han. Assessing the Heat Vulnerability of Different Local Climate Zones in the Old Areas of a Chinese Megacity. Sustainability 2019, 11, 2032 .
AMA StyleZhi Cai, Yan Tang, Kai Chen, Guifeng Han. Assessing the Heat Vulnerability of Different Local Climate Zones in the Old Areas of a Chinese Megacity. Sustainability. 2019; 11 (7):2032.
Chicago/Turabian StyleZhi Cai; Yan Tang; Kai Chen; Guifeng Han. 2019. "Assessing the Heat Vulnerability of Different Local Climate Zones in the Old Areas of a Chinese Megacity." Sustainability 11, no. 7: 2032.
Using SPOT/VGT NDVI time series images (2002–2009) and MODIS/LST images (2002–2009) smoothed by a Savitzky–Golay filter, the land surface phenology (LSP) and land surface temperature (LST), respectively, are extracted for six cities in the Yangtze River Delta, China, including Shanghai, Hangzhou, Nanjing, Changzhou, Wuxi, and Suzhou. The trends of the averaged LSP and LST are analyzed, and the relationship between these values is revealed along the urban–rural gradient. The results show that urbanization advances the start of the growing season, postpones the end of the growing season, prolongs the growing season length (GSL), and reduces the difference between maximal NDVI and minimal NDVI in a year (NDVIamp). More obvious changes occur in surface vegetation phenology as the urbanized area is approached. The LST drops monotonously and logarithmically along the urban–rural gradient. Urbanization generally affects the LSP of the surrounding vegetation within 6 km to the urban edge. Except for GSL, the difference in the LSP between urban and rural areas has a significant logarithmic relationship with the distance to the urban edge. In addition, there is a very strong linear relationship between the LSP and the LST along the urban–rural gradient, especially within 6 km to the urban edge. The correlations between LSP and gross domestic product and population density reveal that human activities have considerable influence on the land surface vegetation growth.
Guifeng Han; Jianhua Xu. Land Surface Phenology and Land Surface Temperature Changes Along an Urban–Rural Gradient in Yangtze River Delta, China. Environmental Management 2013, 52, 234 -249.
AMA StyleGuifeng Han, Jianhua Xu. Land Surface Phenology and Land Surface Temperature Changes Along an Urban–Rural Gradient in Yangtze River Delta, China. Environmental Management. 2013; 52 (1):234-249.
Chicago/Turabian StyleGuifeng Han; Jianhua Xu. 2013. "Land Surface Phenology and Land Surface Temperature Changes Along an Urban–Rural Gradient in Yangtze River Delta, China." Environmental Management 52, no. 1: 234-249.