Impact of urbanization on regional ecosystem services--- a case study in Guangdong-Hong Kong-Macao Greater Bay Area

Ecosystem services (ESs) have been changed significantly due to human and natural interference, especially in urban megaregions. Numerous studies have revealed the impact of urbanization on regional ecosystem service(ES). However, the research on whether urban expansion has sacrificed the areas providing high ESs, which played a crucial role in sustainable development, was poorly understood. This study analyzed the spatial variation of ES supply from 2000 to 2020 under the influence of urban expansion in the Guangdong-Hong Kong-Macao Greater Bay Area (GBA). The result showed that GBA has witnessed high-seeped urban development, and nearly 50% of urban expansion encroached on cropland, 25% on forestland, and 25% on waterbody from 2000 to 2020. Secondly, The ESs changed significantly due to urban expansion. Importantly, nearly 74.48% and 59.74% of areas that urban expansion encroached on were the ecological lands that provided a very high level of ESs from 2000 to 2010 and from 2010 to 2020, respectively. However, the direct impact of urban expansion on the ecological lands providing a very high level of ESs has been decreased. Additionally, the increase in ESs in old urban areas also has a positive role in the regional ES. This study expects to systematically assess the direct impact of urbanization on regional ES and provide scientific information on land use planning for sustainable development.