广佛同城化发展的热岛效应研究

在新常态区域协同发展的机制下,同城化发展的进程不断加快,由此导致的热岛效应影响不断凸显。城市热岛效应的时空变化,是土地利用类型的改变和人们活动等相互作用的结果。本文以广佛同城区域为例,采用2000年和2010年珠三角的土地利用类型数据,利用WRF(Weather & Research Forecasting Model)气象数值模式,分析广佛同城化加速发展带来的热岛效应强度变化。同时,应用连续变化的灯光数据提取2000-2010年间广佛的建成区变化,从个人口密度、户籍数及工业生产总值等角度出发,对广佛同城化区域热岛强度的湿度变化进行相关性和二元回归分析,研究同城化过程中对热岛效应产生的决定性影响。研究表明,广佛交界处的荔湾、南海、白云、三水、番禺、顺德等地区的气温明显高于其他地区,而月平均相对湿度明显低于其他地区,形成大范围的城市热岛和城市干岛。研究还发现,随着建成区面积的增加,热岛强度增强;人口增长及地区生产总值的变化,与广佛同城化区域热岛强度的相关系数超过0.68。总体而言,广佛同城化发展带来人类活动的加强与土地利用类型的改变,对热岛效应具有重要的影响。

Guangzhou-Foshan urban integration and its urban heat island effects

Under the new-normal mechanism of coordinated regional development, the trend of urban integration has been gathering momentum and consequently intensifying urban heat island effects. Spatial-temporal changes in urban heat island effects are a result of interactions between changing land-use pattern, underlying surface variation, and human activities. Base on the case of the Guangzhou-Foshan urban integration area, this study examined the changing intensities of urban heat island effects in the heightened process of Guangzhou-Foshan integration. Apart from analyzing the land-use classification data in the Pearl River Delta as well as formulating a meteorological numerical model—Weather & Research Forecasting Model (WRF), this research aimed to ascertain the determinant factors of urban heat island effects through the following methodology: (1) use the constantly changing nightlight data to investigate the expansion of built-up areas in the Guangzhou-Foshan region between 2000 and 2010; (2) use data on population density, household numbers, and total output values to conduct correlation and multiple regression analyses with the variation of air humidity to reflect the intensity of urban heat island effects in the Guangzhou-Foshan urban integration area. The research findings show that, with the development of Guangzhou-Foshan integration, temperature of the Liwan, Nanhai, Baiyun, Sanshui, Panyu, and Shunde areas at the junction of Guangzhou and Foshan is clearly higher than that of other areas, and the monthly mean relative humidity is clearly lower than other regions, which results in the formation of a large-scale urban heat island and urban dry island. Meanwhile, the size of the built-up area in the city-region is a major factor contributing to the intensity of urban heat island effects in the Guangzhou-Foshan urban integration area. Considerable intensifying impact has also been brought about by population growth and resultant increase in regional output values, the correlation coefficient of the two exceeded 0.68, which indicates that human activities and changes in land-use pattern have also played their part.