Analyzing the Factors and Variables of Heat Island Effect in Comprehensive High-Rise Residential Quarter of Mountain City

2011 ◽  
Vol 356-360 ◽  
pp. 980-985
Author(s):  
Jun Lu ◽  
Chun Die Li ◽  
Liang Wang ◽  
Yu Lu Chen ◽  
Xin Hui Zhang
Keyword(s):  
Thermal Environment ◽  
Linear Regression Analysis ◽  
Multiple Linear Regression Analysis ◽  
Testing Time ◽  
Heat Island ◽  
High Rise ◽  
Island Effect ◽  
Factors Analysis ◽  
Residential Quarter ◽  
Residential Quarters

In order to guide the planning of urban microclimate, the influencing variables of the heat island intensity (UII) of tall residential quarter in mountain city in spring and summer is quantitatively analyzed. Through experiments and simulations, 6 variables including wind speed(WS), green ratio(GR), impervious ratio(IR), average surface temperature(AST) , shadow ratio(SR), H / W were chosen and summarized as factors by dimension reduction in factors analysis; further, the dominant variables and factors in different time were confirmed through multiple linear regression analysis of the factors/ variables and UII. Results revealed that in the microclimate tests, it is appropriate to make factor analysis when the cumulative contribution rate of a factor is higher than 50%, and the significant correlated factor of UII is horizontal surface factor (HSF) in three fifths of the testing time in July. The variable analysis revealed that the significance of WS on UII is more in cloudy days than that in sunny days; the significance of SR is higher in summer than that in transition seasons and is most in 15:00, it demonstrates that optimal utilization of the building shadings is an effective way to improve the outdoor thermal environment in residential quarters.

Green Roof as a Green Material of Building in Mitigating Heat Island Effect in Taipei City

2012 ◽  
Vol 193-194 ◽  
pp. 368-371 ◽  
Author(s):  
Chen Yi Sun ◽  
Yi Jiung Lin ◽  
Wen Pei Sung ◽  
Wen Sheng Ou ◽  
Kang Ming Lu
Keyword(s):  
Green Space ◽  
Thermal Environment ◽  
Green Roof ◽  
Office Building ◽  
Heat Island ◽  
Environmental Benefit ◽  
Island Effect ◽  
Taipei City ◽  
Thermal Influence ◽  
Maximum Cool

A large amount of research has been published in Taiwan on the reduction of the urban temperature for different strategies. The most important strategy for reducing ambient temperature is increasing green space in city. For analyzing the effect of the vegetation on the thermal environment, this paper collects temperature data from one green roof and one normal roof which are belong to a same office building to analyze the thermal influence of vegetation. The result of this research shows that in summer the maximum cool effect of green roof was -1.60 oC and -0.26 oC in average. Therefore, it can also provide useful data to governments for calculating the environmental benefit if they carry out a green roof policy in mitigating heat island effect in the future.

scholarly journals Influence of Weather Factors on Thermal Comfort in Subtropical Urban Environments

2020 ◽  
Vol 12 (5) ◽  
pp. 2001 ◽  
Author(s):  
Chih-Hong Huang ◽  
Hsin-Hua Tsai ◽  
Hung-chen Chen
Keyword(s):  
Thermal Comfort ◽  
Urban Heat Island ◽  
Thermal Environment ◽  
Urban Environments ◽  
Heat Island ◽  
Weather Factors ◽  
Urban Forms ◽  
Thermal Environments ◽  
Island Effect ◽  
Urban Heat

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.

Study on Building Engineering with Simulation and Analysis of Outdoor Thermal Environment for a Residential Subdistrict in Hot Summer/Cold Winter Region

2013 ◽  
Vol 700 ◽  
pp. 235-238
Author(s):  
Liu Zhang ◽  
Yong Hong Huang ◽  
Lian Yang
Keyword(s):  
Thermal Environment ◽  
Wall Material ◽  
Heat Island ◽  
Cold Winter ◽  
Simulation Data ◽  
High Rise ◽  
The North ◽  
Outdoor Thermal Environment ◽  
Air Circulation ◽  
Building Engineering

Thermal environmental problems in urban high-rise buildings are prevalent. To analyze the phenomenon, the thermal environment of a typical urban residential subdistrict is simulated by using CFD techniques considering the affects of different type of wall material. The simulation data are carefully analyzed. Some useful results are thus obtained. The direction of the buildings affects air circulation greatly with the north-south orientation having the best effects. Temperature in the subdistrict is about 3~5°C higher than its surroundings because of heat island effects which could be weakened if greening rate of the sbudistrict is increased. Finally, simulation results show that wall materials affect the environment considerably.

Research on Correlation between Surface Temperature and Nearby Air Temperature of the Underlay

2012 ◽  
Vol 209-211 ◽  
pp. 210-214 ◽  
Author(s):  
Xu Yuan ◽  
Qiong Li ◽  
Qing Lin Meng
Keyword(s):  
Surface Temperature ◽  
Air Temperature ◽  
Thermal Environment ◽  
Urban Climate ◽  
Wave Radiation ◽  
Heat Island ◽  
Island Effect ◽  
Long Wave ◽  
Environment Temperature ◽  
Atmosphere Environment

In the research on urban climate, “heat island effect” is the key point, which directly affects the buildings of city, the traffic, and people's daily life.[1]One important performance of the "heat island effect" is that the bottom atmosphere environment temperature is high, especially the air temperature near the underlay surface, namely air temperature 1.5m high. In the thermal environment which influences people's living and working, air temperature 1.5m high is the most important and direct. [2] It rises mainly by the absorption of the long wave radiation reflected by the underlay surface. So the type of underlay has a very important influence to the air temperature 1.5m high. The underlay surface temperature and the air temperature 1.5m high have a certain grade correlation. This paper is written for the research on the correlation.

scholarly journals Analyzing the Spatial Heterogeneity of the Built Environment and Its Impact on the Urban Thermal Environment—Case Study of Downtown Shanghai

2021 ◽  
Vol 13 (20) ◽  
pp. 11302
Author(s):  
Jiejie Han ◽  
Xi Zhao ◽  
Hao Zhang ◽  
Yu Liu
Keyword(s):  
Built Environment ◽  
Spatial Heterogeneity ◽  
Land Surface ◽  
Urban Areas ◽  
Thermal Environment ◽  
Urban Expansion ◽  
Surface Heat ◽  
Positive Contribution ◽  
Heat Island ◽  
Island Effect

Ongoing urban expansion has accelerated the explosive growth of urban populations and has led to a dramatic increase in the impervious surface area within urban areas. This, in turn, has exacerbated the surface heat island effect within cities. However, the importance of the surface heat island effect within urban areas, scilicet the intra-SUHI effect, has attracted less concern. The aim of this study was to quantitatively explore the relationship between the spatial heterogeneity of a built environment and the intra-urban surface heat island (intra-SUHI) effect using the thermally sharpened land surface temperature (LST) and high-resolution land-use classification products. The results show that at the land parcel scale, the parcel-based relative intensity of intra-SUHI should be attributed to the land parcels featured with differential land developmental intensity. Furthermore, the partial least squares regression (PLSR) modeling quantified the relative importance of the spatial heterogeneity indices of the built environment that exhibit a negative contribution to decreasing the parcel-based intra-SUHI effect or a positive contribution to increasing the intra-SUHI effect. Finally, based on the findings of this study, some practical countermeasures towards mitigating the adverse intra-SUHI effect and improving urban climatic adaption are discussed.

scholarly journals Impact of urbanization on thermal environment of Chengdu-Chongqing Urban Agglomeration under complex terrain

2021 ◽  
Author(s):  
Si Chen ◽  
Zhenghui Xie ◽  
Jinbo Xie ◽  
Bin Liu ◽  
Binghao Jia ◽  
...  
Keyword(s):  
Urban Heat Island ◽  
Urban Area ◽  
Complex Terrain ◽  
Thermal Environment ◽  
Urban Agglomeration ◽  
Urban Heat Island Effect ◽  
Heat Island ◽  
Island Effect ◽  
The Future ◽  
Urban Heat

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.

Quantitative Analysis on Steel Framed Roof’s Temperature Effect

2014 ◽  
Vol 584-586 ◽  
pp. 517-520
Author(s):  
Jie Ying Xiao ◽  
Liu Xi Yu ◽  
Na Ji ◽  
Xing Li
Keyword(s):  
Land Surface ◽  
High Speed ◽  
Thermal Environment ◽  
Heat Island ◽  
City Environment ◽  
Landsat Tm Image ◽  
Island Effect ◽  
Tm Image ◽  
Urban Heat ◽  
The Relationship

With the high speed urbanization process during last two decades, city underlaying surface area and structure changed rapidly, which resulted in urban heat island effect and a series of thermal environment effect.This topic has been received widespread attention from many researchers. Among all kinds of underlaying surfaces, steel framed roof, as a kind of widely used building material, was found playing an important role on contribution to warm regional thermal environment. So it is necessary to study the relationship between steel framed roof and temperature. Based on analyzing Landsat TM image of Shijiazhuang city by remote sensing software, we found that steel framed roof can warm city environment 2-4℃, its area ratio and land surface temperature have a quadratic curve fitting with correlation of 0.7898.

Numerical Simulation on Cooling Effects of Greening for Alleviating Urban Heat Island Effect in North China

2014 ◽  
Vol 675-677 ◽  
pp. 1227-1233 ◽  
Author(s):  
Cheng Chen ◽  
Yu Yue ◽  
Wen Jiang
Keyword(s):  
Numerical Simulation ◽  
Computer Simulation ◽  
Urban Heat Island ◽  
North China ◽  
Thermal Environment ◽  
Heat Island ◽  
Island Effect ◽  
Outdoor Thermal Environment ◽  
Urban Heat ◽  
Cooling Effects

As the climate warming up, the effects of the urban heat island have been an insurmountable issue in the urban development. In this paper, taking Tianjin for example, the research combined computer simulation with on-site measurement to evaluate the effects of different greening ratios on outdoor thermal environment. Besides, the accuracy of the simulation model has been verified by calibration. Research results determined that the increase of the greening ratio in the existing environment could improve the outdoor thermal environment in summer. But the limitations of green cooling was also pointed out, namely that the air temperature would infinitely close to a certain value with further increasing greening ratio.

scholarly journals Outdoor Thermal Environments of Main Types of Urban Areas during Summer: A Field Study in Wuhan, China

2022 ◽  
Vol 14 (2) ◽  
pp. 952
Author(s):  
Kun Li ◽  
Xuefei Li ◽  
Keji Yao
Keyword(s):  
Temperature Difference ◽  
Urban Areas ◽  
Thermal Environment ◽  
Cooling Effect ◽  
Maximum Temperature ◽  
Water Evaporation ◽  
Heat Island ◽  
Maximum Temperature Difference ◽  
Thermal Environments ◽  
Island Effect

Under the influence of the urban heat island effect, the thermal environments of urban built-up areas are poor, leading to the loss of urban vitality and the extreme deterioration of thermal comfort. In this paper, the outdoor thermal environment in Wuhan’s main urban area is studied via the use of field measurements. From June to August in the years 2015 to 2017, 20 measurement points were selected for monitoring from 08:00 to 19:00 h, which were located in spaces such as residential areas, parklands, commercial streets, and college/university campuses. The measurements for the same types of land and different types of land use are analyzed. A comprehensive thermal environment index is used to quantitatively evaluate the overall situations of thermal environments. The results showed that the cooling effect of vegetation shading was stronger than the effect of water evaporation and the maximum temperature difference between the two cooling methods reached 6.1 °C. The cooling effect of the canopy shading of tall trees was stronger than the effect of grassland transpiration and the maximum temperature difference was 2.8 °C. The streets with higher aspect ratios might improve the ventilation, but the wind speeds remained low, which did not provide a strong cooling effect. This study helps urban planners understand the thermal environment of Wuhan or similar cities with hot summer and diversified urban areas, and puts forward suggestions to reduce the heat island effect from the aspect of building layout, green coverage, shading mode, and street aspect ratio, so as to establish sustainable cities that are climate adaptable and environmentally friendly.

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