Rapid Urbanization Induced Extensive Forest Loss to Urban Land in the Guangdong-Hong Kong-Macao Greater Bay Area, China

Abstract

China has experienced rapid urbanizations with dramatic land cover changes since 1978. Forest loss is one of land cover changes, and it induces various eco-environmental degradation issues. As one of China's hotspot regions, the Guangdong-Hong Kong-Macao Greater Bay Area (GBA) has undergone a dramatic urban expansion. To better understand forest dynamics and protect forest ecosystem, revealing the processes, patterns and underlying drivers of forest loss is essential. This study focused on the spatiotemporal evolution and potential driving factors of forest loss in the GBA at regional and city level. The Landsat time-series images from 1987 to 2017 were used to derive forest, and landscape metrics and geographic information system (GIS) were applied to implement further spatial analysis. The results showed that: 1) 14.86% of the total urban growth area of the GBA was obtained from the forest loss in 1987-2017; meanwhile, the forest loss area of the GBA reached 4040.6 km 2 , of which 25.60% (1034.42 km 2 ) was converted to urban land; 2) the percentages of forest loss to urban land in Dongguan (19.14%), Guangzhou (18.35%) and Shenzhen (15.81%) were higher than those in other cities; 3) the forest became increasingly fragmented from 1987-2007, and then the fragmentation decreased from 2007 to 2017); 4) the landscape responses to forest changes varied with the scale; and 5) some forest loss to urban regions moved from low-elevation and gentle-slope terrains to higher-elevation and steep-slope terrains over time, especially in Shenzhen and Hong Kong.Urbanization and industrialization greatly drove forest loss and fragmentation, and, notably, hillside urban land expansion may have contributed to hillside forest loss. The findings will help policy makers in maintaining the stability of forest ecosystems, and provide some new insights into forest management and conservation.

Human expansion into Asian highlands in the 21st Century and its effects

“…Recent studies indicates that human activities are still expanding regionally in some Asian highlands, such as the cultivated land expansions in Southeast Asia 13 , 14 and the hillside urban land expansions in China 7 , 15 . Moreover, many of these expansions have caused forest loss 3 , 13 , 14 , 16 , 17 . These types of regional human activities in highlands diverge from the general view that the expanding agricultures or human settlements in hills and mountains are not economically feasible (see the high-resolution evidence of typical human activity expansions in some Asian highlands; Supplementary Figs.…”

Identifying the Impacts of Land‐Use Spatial Patterns on Street‐Network Accessibility Using Geospatial Methods

“…With further regional integration in the GBA, more intercity transportations, such as Guangzhou‐Shenzhen Railway, are expected to travel through Dongguan, having considerable impacts on land‐use spatial patterns. In the last three decades, the urban areas in Dongguan increased by almost 25 times (Yang et al, 2019), and about 19% of the total areas of forests are converted into urban areas in Dongguan that are the highest among all cities in the GBA (Yang et al, 2021). Land‐use variations are affecting the street‐network structure.…”

Unveiling the Coupling Coordination and Interaction Mechanism between the Local Heat Island Effect and Urban Resilience in China

“…China has experienced rapid urbanization since 1978, during which the Guangdong-Hong Kong-Macao Greater Bay Area (GBA) has undergone a dramatic urban expansion [55]. With the increase in population, energy consumption, and anthropogenic heat generation, urban systems will face risks brought by UHIs in terms of resilience in multiple functional subsystems, such as economy, society, ecology, and engineering.…”