scholarly journals Comparison of Potential Contribution of Typical Pavement Materials to Heat Island Effect

2020 ◽  
Vol 12 (11) ◽  
pp. 4752 ◽  
Author(s):  
Hailu Yang ◽  
Kai Yang ◽  
Yinghao Miao ◽  
Linbing Wang ◽  
Chen Ye
Keyword(s):  
Asphalt Concrete ◽  
Asphalt Mixture ◽  
Potential Contribution ◽  
Heat Island ◽  
Cement Concrete ◽  
Porous Asphalt ◽  
Pavement Materials ◽  
Island Effect ◽  
Urban Heat ◽  
Better Than

Pavement materials have significant influence on the urban heat island effect (UHIE). This paper presents a study on the potential effects of pavement materials on UHIE in a natural environment. Three typical pavement materials, including cement concrete, dense asphalt concrete and porous asphalt mixture, were selected to evaluate their anti-UHIE properties by testing. In this paper, heat island potential (HIP) is proposed as a new index to analyze the influence of pavement materials on UHIE. It is shown that the temperature inside a pavement distinctly depends on the depth, and varies, but is usually higher than the air temperature. Solar radiation in the daytime significantly contributes to the temperature of pavement surface and the upper part. The correlation becomes weak at the middle and the bottom of pavements. Among the three materials tested in this study, the anti-UHIE performance of cement concrete is significantly higher than that of the other asphalt mixtures, while the porous asphalt mixture is slightly better than the dense asphalt concrete in anti-UHIE.

Contrastive Studies of Asphalt Pavement on Suction Exothermic Properties and Cooling Measures

2011 ◽  
Vol 97-98 ◽  
pp. 290-296
Author(s):  
Wei Guang Li ◽  
Zhi Dong Han ◽  
Zhen Bei Lv ◽  
Yan Hong Duan
Keyword(s):  
Heat Storage ◽  
Asphalt Pavement ◽  
Asphalt Mixture ◽  
Heat Island ◽  
Regular Pattern ◽  
Island Effect ◽  
Different Types ◽  
Urban Heat ◽  
Pavement Structure ◽  
Quantity Of Heat

It is important to reduce asphalt mixture strong absorption characteristics to improve anti-rutting ability and reduce the urban heat island effect. This paper firstly studies the suction and exothermic regular pattern of existing three types, five kinds of asphalt pavement structure. It turns out that there are differences in suction and exothermic characteristics of different types of pavement structure. Suspension close-grained type structure has higher adiabatic heating; gap-type skeleton has faster speed of suction and exothermic; and dense skeleton has more total quantity of heat storage. Accordingly, test and analysis of cooling effect of Gap-type skeleton asphalt pavement has conducted by adopting smear reflective materials to reduce reflectance and surface adding insulation materials, The results show that reducing reflectivity is the best way which can reduce by 5 centigrade around. In addition , improving effectiveness has also been studied by adding light-colored stone partly replacing mineral aggregate, and substituting busing mullite for aggregate below2.36 mm is the best cooling way ,which can reduce by 3.3 centigrade.

scholarly journals The Albedo of Pervious Cement Concrete Linearly Decreases with Porosity

2015 ◽  
Vol 2015 ◽  
pp. 1-5 ◽  
Author(s):  
Rui Zhang ◽  
Guosheng Jiang ◽  
Jia Liang
Keyword(s):  
Portland Cement ◽  
Urban Heat Island ◽  
Spectral Reflectance ◽  
Pervious Concrete ◽  
Heat Island ◽  
Portland Cement Concrete ◽  
Cement Concrete ◽  
Solar Absorption ◽  
Island Effect ◽  
Urban Heat

Pervious pavements have been advocated as a potential countermeasure to the urban heat island effect. To understand if pervious pavements stay cooler than conventional pavements, the albedo of the pervious concrete must be understood. This study measured the albedo of pervious concrete with different porosity. Four Portland cement concrete mixes were casted, using designed amounts of sand to vary the porosity of the pervious concrete samples. The samples were sliced and the spectral reflectance and albedo of the sliced samples were measured and analyzed. It is found that the albedo of pervious concrete decreases linearly with the increase of the porosity. The albedo of a pervious Portland concrete varies from 0.25 to 0.35, which is 0.05~0.15 lower than the albedo of conventional cement concrete. Due to this lower albedo, it should be cautious to develop pervious concrete to battle with urban heat island unless the evaporation of pervious concrete is promoted to compensate the additional solar absorption caused by the low albedo.

scholarly journals Detecting the Cool Island Effect of Urban Parks in Wuhan: A City on Rivers

2020 ◽  
Vol 18 (1) ◽  
pp. 132
Author(s):  
Qijiao Xie ◽  
Jing Li
Keyword(s):  
Remote Sensing ◽  
Negative Impact ◽  
Remote Sensing Data ◽  
Urban Parks ◽  
High Water ◽  
Water Bodies ◽  
Green Spaces ◽  
Heat Island ◽  
Island Effect ◽  
Urban Heat

As a nature-based solution, development of urban blue-green spaces is widely accepted for mitigating the urban heat island (UHI) effect. It is of great significance to determine the main driving factors of the park cool island (PCI) effect for optimizing park layout and achieving a maximum cooling benefit of urban parks. However, there have been obviously controversial conclusions in previous studies due to varied case contexts. This study was conducted in Wuhan, a city with high water coverage, which has significant differences in context with the previous case cities. The PCI intensity and its correlation with park characteristics were investigated based on remote sensing data. The results indicated that 36 out of 40 urban parks expressed a PCI effect, with a PCI intensity of 0.08~7.29 °C. As expected, larger parks with enough width had stronger PCI intensity. An increased density of hardened elements in a park could significantly weaken PCI effect. Noticeably, in this study, water bodies in a park contributed the most to the PCI effect of urban parks, while the vegetated areas showed a negative impact on the PCI intensity. It implied that in a context with higher water coverage, the cooling effect of vegetation was weakened or even masked by water bodies, due to the interaction effect of different variables on PCI intensity.

scholarly journals Cooling Effect of Different Land Cover Types: A Case Study in Xi’an and Xianyang, China

2021 ◽  
Vol 13 (3) ◽  
pp. 1099
Author(s):  
Yuhe Ma ◽  
Mudan Zhao ◽  
Jianbo Li ◽  
Jian Wang ◽  
Lifa Hu
Keyword(s):  
Land Cover ◽  
Surface Temperature ◽  
Urban Heat Island ◽  
Land Surface Temperature ◽  
Land Surface ◽  
Cooling Effect ◽  
Heat Island ◽  
Land Cover Types ◽  
Island Effect ◽  
Urban Heat

One of the climate problems caused by rapid urbanization is the urban heat island effect, which directly threatens the human survival environment. In general, some land cover types, such as vegetation and water, are generally considered to alleviate the urban heat island effect, because these landscapes can significantly reduce the temperature of the surrounding environment, known as the cold island effect. However, this phenomenon varies over different geographical locations, climates, and other environmental factors. Therefore, how to reasonably configure these land cover types with the cooling effect from the perspective of urban planning is a great challenge, and it is necessary to find the regularity of this effect by designing experiments in more cities. In this study, land cover (LC) classification and land surface temperature (LST) of Xi’an, Xianyang and its surrounding areas were obtained by Landsat-8 images. The land types with cooling effect were identified and their ideal configuration was discussed through grid analysis, distance analysis, landscape index analysis and correlation analysis. The results showed that an obvious cooling effect occurred in both woodland and water at different spatial scales. The cooling distance of woodland is 330 m, much more than that of water (180 m), but the land surface temperature around water decreased more than that around the woodland within the cooling distance. In the specific urban planning cases, woodland can be designed with a complex shape, high tree planting density and large planting areas while water bodies with large patch areas to cool the densely built-up areas. The results of this study have utility for researchers, urban planners and urban designers seeking how to efficiently and reasonably rearrange landscapes with cooling effect and in urban land design, which is of great significance to improve urban heat island problem.

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