广州市中心城区人为热排放景观格局的时空变化

The Spatial-temporal Landscape Pattern Variation According to the Anthropogenic Heat in the Central Area of Guangzhou

  • 摘要: 为了探究人为热排放对城市生态环境的影响,以广州市中心城区为研究区,利用Landsat数据和地表能量平衡方程,研究了2004—2020年城市人为热排放时空演变状况,结合转移矩阵和景观格局指数分析了人为热排放的时空变化特征及景观格局变化规律. 结果表明:(1)从时间上来看,2004—2014、2014—2020年的人为热排放变化分别以区域快速扩张、强度明显增强为主要特点;从空间上来看,广州市中心城区南部的人为热排放强度比北部的高. (2)人为热排放转移矩阵显示2004—2020年广州市中心城区人为热排放变化显著,低排放区面积占比的变化幅度最大(减少15.72%),其次是中排放区(增加14.51%),高排放区面积占比的变化幅度最小(增加0.28%). 由低排放区转为其他类型的比例高达97.36%,由其他类型转为中排放区的比例高达98.43%,构成了人为热排放变化的主要形式. (3)景观水平上,景观聚集度指数(CONTAG)上升,香农多样性指数(SHDI)和修正Simpon均匀度指数(MSIEI)下降,中心城区的人为热排放景观异质性增强,破碎程度提高;不同等级区人为热排放的景观格局演变具有明显差异,其中,低强度排放景观格局(低排放区、低中排放区)趋于稳定性、规则化,高强度排放景观格局(中排放区、中高排放区、高排放区)趋于破碎化、不规则化.

     

    Abstract: In order to explore the impact of anthropogenic heat emissions on the urban ecological environment, the central urban area of Guangzhou was taken as the research area, the temporal and spatial evolution of urban anthropogenic heat emissions from 2004 to 2020 were explored using the Landsat remote sensing data and the surface energy balance model, and the spatial-temporal characteristics of anthropogenic heat emissions and the norms of the landscape pattern change were analyzed with the transfer matrix and the landscape pattern index. The following results were obtained. First, in terms of time, rapid expansion of anthropogenic heat emission area was the main feature from 2004 to 2014 and dramatic increase of anthropogenic heat emission intensity was the main feature from 2014 to 2020; in terms of space, the intensity of anthropogenic heat emission in the southern part was higher than that in the northern part. Second, as the transfer matrix showed, the anthropogenic heat emission in the central area of Guangzhou changed significantly during the study period. The area of low-emission zone (decreased by 15.72%) in central area changed the most, the area of medium-emission zone (increased by 14.51%) underwent less change, and the area of high-emission zone (increased by 0.28%) changed the least. Transfer from low-emission zone and transfer into middle-emission zone were the main forms, accounting for 97.36% and 98.43% respectively. Third, the contagion index (CONTAG) increased, while the shannon's diversity index (SHDI) and the modified simpon evenness index (MSIEI) decreased. Consequently, the landscape pattern heterogeneity and the degree of fragmentation of anthropogenic heat emission increased. Moreover, there were obvious differences in the evolution of the landscape pattern in zones of different levels of anthropogenic heat emission. The landscape pattern of low- and low-medium-emission zones tend to be stable and regular while the landscape pattern of medium-, medium-high- and high-emission zones tend to be fragmented and irregular.

     

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