Evaluation of urban ecological benefits utilizing vegetated areas metrics in Nanjing, China

Abstract

Vegetation areas are vital for enhancing the sustainability of urban ecosystems. However, ongoing urbanization gradually reduces these areas in cities, leading to a decline in ecological benefits. This study integrates fractional vegetation cover and land surface temperature in understanding the changes in vegetated areas and ecological benefits from 1990 to 2020 in eight central districts of Nanjing using the CITYgreen model and geographically weighted regression. The findings show that human intervention resulted in a reduction of urban vegetated areas by 22.84%, while non-vegetated areas have increased by 1.24 times. The total value of ecological benefits was reduced by approximately 57.41%. The landscape pattern experienced gradual fragmentation, evidenced by a decrease of approximately 62% in the largest patch index (LPI). Both the mean shape index (SHAPE-MN) and landscape shape index (LSI) showed significant increases, indicating a rise in the complexity of landscape patches due to human intervention.

Keywords

• Urbanization
• vegetated areas
• ecological benefit
• spatiotemporal evolution
• landscape pattern
• fractional vegetation cover