Abstract: Impervious surface has emerged not only as an important indicator of the degree of urbanization, but also a major indicator of environmental quality, which has been considered as a significant topic in the application of urban geography and ecology. With the rapid development of urbanization and increase of impervious surface, a growing number of urban governors and environmental managers have paid attention to the distribution of impervious surfaces. This paper examines the spatial-temporal changes and its dynamics of impervious surface areas (ISA) in Guangdong-Hong Kong-Macao Greater Bay Area using time series Landsat imagery from the perspective of urban geography with the supports of Remote Sensing (RS) and Geographic Information System (GIS). Linear spectral mixture analysis (LSMA) has been applied to estimate ISA, and the results of ISA were calculated by a thresholding method with impervious surface fraction >0.5. The results show that the ISA increases from 12 127.69 km2 to 20 188.87 km2 between 2006 and 2016, with an average annual growth rate of 6.65%. Meanwhile, the spatial distribution of ISA is becoming more and more concentrative. Additionally, this study reveals that the increase speed and direction of ISA and urban expansion and urban traffic have strong relationship, especially the national highway having the most prominent relationship among all of the styles of traffics. Economic development (gross domestic product, GDP) and permanent population have positive effects on increase of ISA, with correlation coefficient (R2) of 0.840 7 and 0.834 1, respectively. Furthermore, the development of stages and patterns in Guangdong-Hong Kong-Macao Greater Bay Area are different. The impervious surfaces of Guangdong-Hong Kong-Macao Greater Bay Area have experienced significant changes in the past decades. The objective of this study is to quantify the dynamics of ISA in Guangdong-Hong Kong-Macao Greater Bay Area for its sustainable urban planning and management strategy. In the future urban development, we should coordinate the expansion scope and speed of ISA in Guangdong-Hong Kong-Macao Greater Bay Area, avoiding the environmental problem caused by blind urban expansion.

Key words: impervious surface, remote sensing, urban geography, the Guangdong-Hong Kong-Macao Greater Bay Area