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

Abstract

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.

The Challenge in the Management of Historic Trees in Urban Environments during Climate Change: The Case of Corso Trieste (Rome, Italy)

“…Analysing the results, it is possible to observe that, in line with the scientific literature, due to their shading effect, energy balance and transpiration cooling, vegetation results to be the most effective strategy to mitigate daytime urban human heat stress and so it is an important climate change mitigation strategy [37][38][39][40][41]. Specifically, here, the presence of Pinus pinea L. has a positive effect on the mitigation of air temperature and the improvement of thermal comfort along Corso Trieste.…”

Dynamic Changes of Local Climate Zones in the Guangdong–Hong Kong–Macao Greater Bay Area and Their Spatio-Temporal Impacts on the Surface Urban Heat Island Effect between 2005 and 2015

“…When obtained from thermal infrared remote sensing imagery, LST can represent the continuous daytime or nighttime temperatures over a larger geographic area than air temperature [11]. Hence, LST has become a key variable in the study of the surface UHI (SUHI) effect during the urbanization process [12][13][14][15][16][17].…”

Coupling Relationship of Urban Development and the Eco-Environment in Guanzhong Region, China

“…The results of this study show that: (1) From 2001 to 2018, the CNLI in the Guanzhong region has increased steadily, the level of urban development has gradually improved, and the connection between intra-regional cities has continuously strengthened. (2) The RSEI in the Guanzhong region gradually increased during the study period and the eco-environmental conditions have improved, but the overall level was low. (3) Although the overall coupling situation and degree of coordination between urban development and the eco-environment in the Guanzhong region were increasing, the eco-environment lagged behind urban development.…”

“…It is expected that the total urban population will reach 70% by 2050 [1]. The expansion of the urban scale changes the physical properties of the urban underlying surface, and an artificial impervious surface replaces the original natural surface [2]. This is an important reason for the increasingly serious urban ecological environment problems, such as cultivated land reduction, air pollution, water pollution, and urban heat islands [3].…”