Research on the cold-island effect with desertification process based on the QiTai oasis

2007 ◽  
Author(s):  
Qingsan Shi ◽  
Qingdong Shi ◽  
Wei Gao ◽  
Bingfeng Ma ◽  
Yuhu Zhang
Keyword(s):  
Island Effect ◽  
Desertification Process ◽  
Cold Island Effect

Numerical Simulation on Oasis Effect over Northwestern China

2013 ◽  
Vol 448-453 ◽  
pp. 897-901
Author(s):  
Xiao Hang Wen
Keyword(s):  
Energy Budget ◽  
Sensible Heat Flux ◽  
Wrf Model ◽  
Forecast Model ◽  
Surface Energy Budget ◽  
Wind Fields ◽  
Island Effect ◽  
Latent Flux ◽  
Cold Island Effect ◽  
Surface Layer Temperature

The characteristics of air temperature, circulation and energy budget of Jinta Oasis are simulated by WRF model, which is the weather research and forecast model of NCAR. The results show that the WRF model has good quality in simulating the diurnal characteristics of surface layer temperature, wind fields, net radiation, sensible heat flux and latent flux. In addition, the model initial fields were also modified by observations of soil temperature and moisture in order to improve the simulations in this study due to important roles of the soil moisture and temperature playing in affecting the cold island effect, the wet island effect properties and surface energy budget balance over the oasis in arid area. Then, the microclimate characteristics and local thermal circulation generated by inhomogeneous underlying surface over Jinta Oasis are analyzed.

Influence of the low-level jet on the intensity of the nocturnal oasis cold island effect over northwest China

2019 ◽  
Vol 139 (1-2) ◽  
pp. 689-699 ◽  
Author(s):  
Bangjun Cao ◽  
Yu Zhang ◽  
Yong Zhao ◽  
Xiaohang Wen ◽  
Guangzhou Fan ◽  
...  
Keyword(s):  
Northwest China ◽  
Low Level ◽  
Island Effect ◽  
Low Level Jet ◽  
Cold Island Effect

scholarly journals Impacts of Neighboring Buildings on the Cold Island Effect of Central Parks: A Case Study of Beijing, China

2020 ◽  
Vol 12 (22) ◽  
pp. 9499
Author(s):  
Dongrui Han ◽  
Xiaohuan Yang ◽  
Hongyan Cai ◽  
Xinliang Xu
Keyword(s):  
Land Surface ◽  
Shape Index ◽  
Effective Measure ◽  
High Rise ◽  
Island Effect ◽  
Rational Allocation ◽  
Neighboring Building ◽  
Urban Heat ◽  
Cold Island Effect ◽  
The Impact

Urban parks have been considered as an effective measure to mitigate the urban heat island (UHI) effects. Many studies have investigated the impacts of shape, size and interior components on the cold island effect (CIE) of parks, while little attention has been given to the impact of neighboring buildings. Thus, taking twenty-two parks in Beijing as samples, this study investigated the impacts of the neighboring building on the CIE of central parks. The results showed that the average land surface temperature (LST) of parks are 30.98 °C in summer and −1.10 °C in winter. Parks have a strong CIE in summer, and average cold island footprint (CIF) and LST difference are 0.15 km2 and 2.01 °C higher than that in winter. The components of the building in the CIF of parks are dominated by middle-rise building (MRB), followed by low-rise building (LRB), and high-rise building (HRB) is the least dominant. The percentage of landscape (PLAND) and landscape shape index (LSI) of MRB, and perimeter area fractal dimension (PAFRAC) of LRB are significantly related to CIF in summer and winter. This study could extend scientific understanding of the impacts of neighboring buildings on the CIE of central parks, and could guide urban planners in mitigating the UHI effects through the rational allocation of buildings.

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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