Urban heat island in Shanghai, China

Abstract

With rapid urbanization and industrialization, urban heat island effect in Shanghai is increasing. Based on the observed data, image data, and statistic data, temporal variation and spatial distribution of urban heat island and its relationship with urbanization factors in Shanghai was analyzed in this study. The results indicated the UHI index between urban and rural area increased with a rate of 0.2 Celsius degree per 10 years from 1959 to 2005, while that between urban and suburban decreased from 1995, that is to say, the heat island in Shanghai expanded. The increasing UHI index between urban and rural area and the decreasing UHI index between urban and suburb area are related to the increase trend of mean annual temperature among districts. The UHI in Shanghai is stronger in urban area, Minhang, Northeast and middle Songjiang, and South Jinshan. The distribution of UHI is well corresponding with the land use types, both urban area and 9 towns in Shanghai are all heat islands. A good logarithmic relationship was obtained between UHI index and the number of operating buses, area of building completed, area of paved road and gross domestic product, and a good linear relationship was occurred between UHI index and the final consumption of energy by industry, power consumption of industry, total registered population and area of cultivated land.

Temporal and spatial characteristics of the urban heat island during rapid urbanization in Shanghai, China

“…Using data from ten meteorological stations, Zhao et al (2006) found that the difference in mean annual temperature between four urban stations (Xujiahui, Minhang, Jiading, Baoshan) and six rural stations (Nanhui, Fengxian, Songjiang, Jinshan, Qingpu, Chongming) increased from 0.1 • C in the late 1970s to 0.7 • C in the early 2000s, with an increase of 0.24 • C per decade. The results of Cui et al (2007) showed that the UHI intensity between one urban station (Xujiahui) and six rural stations (Nanhui, Fengxian, Songjiang, Jinshan, Qingpu, Chongming) increased at a rate of 0.21 • C per decade from 1959 to 2005. These studies imply that the UHI intensity has increased significantly with the rapid expansion of Shanghai.…”

The Migration of the Warming Center and Urban Heat Island Effect in Shanghai During Urbanization

“…The annual UHI occurrence frequency was 87.8%, and the monthly mean UHI intensity was larger than 0.8 • C based on the temperature observations of six Davis automatic stations in urban and suburban areas (Deng et al, 2001). The increasing rate of UHI intensity was 0.21 • C/10a from 1959 to 2005 (Cui et al, 2007). Based on temperature observation data of 59 automatic weather stations from 2006 to 2013, the study indicated that there were three heat island centers in Shanghai, that is, in addition to the main heat island center in the urban area, there were also two sub-heat island centers in the northern part of Minhang and the southern part of Songjiang (Shen et al, 2017).…”

Effect of Ultrasonic Vibration Frequency on Ni-Based Alloy Cladding Layer

“…Second, the ultrasonic cavitation makes the cladding layer grains very fine, thereby increasing the average microhardness of the cladding layer. Third, the cavitation and acoustic flow effects of ultrasonic vibration significantly reduce the porosity in the molten pool, thereby increasing the microhardness [6,16,17]. Fourth, as can be shown by the Hall-Petch formula [18], the yield strength of the material increases as the grain diameter decreases, and the ultrasound refines the grains, which in turn increases the hardness of the coating.…”