Analysis of spatiotemporal changes and driving factors of blue-green space in six metropolitan areas of the Yangtze River Delta based on the PLUS model

Abstract

This study aims to examine the evolution of blue-green space and urban development in the Yangtze River Delta region using Arcgis spatial analysis, landscape pattern index, and PLUS model to inform urban planning and environmental protection efforts. The results indicate that:1) Blue space in the region's six metropolitan areas initially increased, then decreased significantly from 2000-2020, while green space continued to decline. However, recent environmental policies have mitigated this trend. 2) Improved living standards have led to increased green space within cities, but construction land occupation has reduced green space outside of cities. 3) Blue-green space is becoming more fragmented, scattered, and homogenized in shape, and that economic development influences green space, while different regional development patterns impact blue space. 4) Socioeconomic and natural factors both drive blue-green space to change. There is a "dual desirability" between blue-green space protection and urban development. In conclusion, the scale and landscape pattern of blue-green space have changed significantly in the last 20 years, which are greatly influenced by urban development, and the blue-green space differences among metropolitan areas are obvious. Therefore, it is necessary to protect and optimize the blue-green space pattern of the metropolitan areas.