Analysis of thermal environment and urban heat island using remotely sensed imagery over the north and south slope of the Qinling Mountain, China

Author(s):  
Dengzhong Zhao ◽  
Wanchang Zhang ◽  
Bin Yong
2014 ◽  
Vol 96 (2) ◽  
pp. 198-214 ◽  
Author(s):  
Adeline Ngie ◽  
Khaled Abutaleb ◽  
Fethi Ahmed ◽  
Ahmed Darwish ◽  
Mahmoud Ahmed

2015 ◽  
Vol 04 (01) ◽  
pp. 35-47 ◽  
Author(s):  
Khaled Abutaleb ◽  
Adeline Ngie ◽  
Ahmed Darwish ◽  
Mahmoud Ahmed ◽  
Sayed Arafat ◽  
...  

2013 ◽  
Vol 52 (11) ◽  
pp. 2418-2433 ◽  
Author(s):  
A. M. E. Winguth ◽  
B. Kelp

AbstractHourly surface temperature differences between Dallas–Fort Worth, Texas, metropolitan and rural sites have been used to calculate the urban heat island from 2001 to 2011. The heat island peaked after sunset and was particularly strong during the drought and heat wave in July 2011, reaching a single-day instantaneous maximum value of 5.4°C and a monthly mean maximum of 3.4°C, as compared with the 2001–11 July average of 2.4°C. This severe drought caused faster warming of rural locations relative to the metropolitan area in the morning as a result of lower soil moisture content, which led to an average negative heat island in July 2011 of −2.3°C at 1100 central standard time. The ground-based assessment of canopy air temperature at screening level has been supported by a remotely sensed surface estimate from the Moderate Resolution Imaging Spectroradiometer (MODIS) on board the Terra satellite, highlighting a dual-peak maximum heat island in the major city centers of Dallas and Fort Worth. Both ground-based and remotely sensed spatial analyses of the maximum heat island indicate a northwest shift, the result of southeast winds in July 2011 of ~2 m s−1 on average. There was an overall positive trend in the urban heat island of 0.14°C decade−1 in the Dallas–Fort Worth metropolitan area from 2001 to 2011, due to rapid urbanization. Superimposed on this trend are significant interannual and decadal variations that influence the urban climate.


2020 ◽  
Vol 12 (5) ◽  
pp. 2001 ◽  
Author(s):  
Chih-Hong Huang ◽  
Hsin-Hua Tsai ◽  
Hung-chen Chen

Urbanization has influenced the distribution of heat in urban environments. The mutual influence between weather factors and urban forms created by dense buildings intensify human perception of the deteriorating thermal environment in subtropics. Past studies have used real-world measurements and theoretical simulations to understand the relationship between climate factors and the urban heat island effect. However, few studies have examined how weather factors and urban forms are connected to the thermal environment. To understand the influence of various weather factors on urban thermal environments in various urban forms, this study applied structural equation modeling to assumptions of linear relationships and used quantitative statistical analysis of weather data as well as structural conversion of this data to establish the structural relationships between variables. Our objective was to examine the relationships among urban forms, weather factors, and thermal comfort. Our results indicate that weather factors do indeed exert influence on thermal comfort in urban environments. In addition, the thermal comfort of urban thermal environments varies with location and building density. In hot and humid environments in the subtropics, humidity and wind speed have an even more profound impact on the thermal environment. Apparent temperature can be used to examine differences in thermal comfort and urban forms. This study also proved that an urban wind field can effectively mitigate the urban heat island effect. Ventilation driven by wind and thermal buoyancy can dissipate heat islands and take the heat away from urban areas.


Author(s):  
Chen Yang ◽  
Qingming Zhan ◽  
Sihang Gao ◽  
Huimin Liu

Conspicuous expansion and intensification of impervious surfaces accompanied by rapid urbanization are widely recognized to have exerted evident impacts on the urban thermal environment. Investigating the spatially and temporally varying relationships between Land Surface Temperature (LST) and impervious surfaces (IS) at multiple scales is of great significance for steering IS expansion and intensification. This study proposes an analytical framework to investigate the spatiotemporal variations of LST and its responses to IS in Wuhan, China at both city scale and sub-region scale. The summer LST patterns in 2002–2017 are extracted by Multi-Task Gaussian Process (MTGP) model from raw 8-day synthesized MODerate-resolution Imaging Spectroradiometer (MODIS) LST data. At the city scale, the weighted center of LST (LSTWC) and impervious surface fraction (ISFWC), multi-temporal trajectories and coupling indicators are utilized to comprehensively examine the spatial and temporal dynamics of LST and IS within Wuhan. At the sub-region scale, urban heat island ratio index (URI), impervious surfaces contribution index (ISCI) and sprawl rate are introduced for further quantifying the relationships of LST and IS. The results reveal that IS and hot thermal landscapes expanded by 407.43 km2 and 255.82 km2 in Wuhan in 2002–2017 at city scale. The trajectories of LSTWCs and ISFWCs are visually coherent and both heading to southeast direction in general. At the sub-region scale, the specific cardinal directions with the highest ISCI variations are examined to be the exact directions of ISFWC trajectories in 2002–2017. The results reveal that the spatiotemporal variations of LST and IS are highly correlated at both city and sub-region scales within Wuhan, thus testifying the significance of steering IS expansion and renewal for controlling urban thermal environment deterioration.


2016 ◽  
Author(s):  
Weimin Wang ◽  
Liang Hong ◽  
Lijun Yang ◽  
Lihuan He ◽  
Guihua Dong

2021 ◽  
Author(s):  
Si Chen ◽  
Zhenghui Xie ◽  
Jinbo Xie ◽  
Bin Liu ◽  
Binghao Jia ◽  
...  

Abstract. Located in the mountainous area of southwest China, the Chengdu-Chongqing Urban Agglomeration (CCUA) was rapidly urbanized in the last four decades, has led to a three-fold urban area expansion, thereby affecting the weather and climate. To investigate the urbanization effects on the thermal environment in the CCUA under the complex terrain, we conducted the simulations using the advanced Weather Research and Forecasting (WRF V4.1.5) model together with the combining land-use scenarios and terrain conditions. We observed that the WRF model reproduces the general synoptic summer weather pattern, particularly for the thermal environment. It was shown that the expansion of the urban area changed the underlying surface's thermal properties, leading to the urban heat island effect, enhanced by the complex terrain further. The simulation with the future scenario shows that the implementation of idealized measures including returning farmland to forests, expanding rivers and lakes can reduce the urban heat island effect and regulate the urban ecosystem. Therefore, the urban planning policy can has potential to provide feasible suggestions to best manage the thermal environment of the future city toward improving the livelihood of the people in the environment.


2020 ◽  
Author(s):  
Xuan Ma ◽  
Jingyuan Zhao ◽  
Lei Zhang

Abstract BackgroundIncreasing urban heat island and global warming have aroused serious thermal environmental problems, even do harm to people’s thermal health. Because the importance in people’s daily life, Commercial pedestrianized block represents a symbol of a city or metropolis, therefore, focusing the attention on the thermal environment in such regions is very necessary. Most of the researches on urban thermal environment are calculated by remote sensing data, limited by the low spatial resolution of remote sensing image, it may not obviously reflect the true thermal environment of the research site, especially in some micro-scale regions. MethodsBased on this, the new software ENVI-met is developed to research the thermal environment and forecast people’s thermal sensation in micro-scale region. ResultsTherefore, the objective of this study aims at conducting field measurement and numerical simulation to assess the thermal environment of a typical commercial pedestrianized space in southern China, and assess the different urban design parameter in ameliorating urban heat island effect. ConclusionsOur final results demonstrate a quantitative evidence for establishing a comprehensive standard for improving thermal environment in micro-scale region, and this study also can be a supplementary in the research field about improving thermal health.


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