Spatial-Temporal Divergence and Coupling Analysis of Land Use Change and Ecosystem Service Value in the Yangtze River Delta Urban Agglomeration

Land use changes (LUC) have exacerbated the evolution of ecosystem structure in the urban agglomeration of the Yangtze River Delta (YRDUA), significantly affecting ecosystem service functions and values. Although the impact of land use on ecosystem service value (ESV) has received significant attention, most existing studies explore the relationship between LUC and ESV at the national, provincial, or regional scales. Few studies focus on urban agglomerations, particularly in the YRDUA. Additionally, while many studies analyze the driving factors of ecosystem services and the trade-offs and synergies among them, there is a relative scarcity of research on the coupling coordination relationship between LUC and ESV. In this study, we used the ecosystem service assessment model to dynamically analyze the spatio-temporal changes of land use and ESV in the YRDUA from 2000 to 2020 and evaluated the dynamic relationship between the two using the coupled coordination model system. The results show the following: (1) Land use types within the YRDUA underwent significant changes during the study period, with a notable decrease in farmland and a substantial increase in construction land being the dominant trends. (2) ESV showed upward and downward trends over different periods, with water bodies having the highest value, followed by forested land and farmland, respectively. The ESV of water bodies showed a trend of first increasing and then decreasing. Higher ESVs were mainly concentrated around lakes such as Taihu Lake and coastal areas along the Yangtze River, radiating outward from these central points. (3) Currently, the coupling coordination degree (CCD) between land use intensity and ESV in the YRDUA is mostly reluctant coordinated or in the state of primary coordination. However, with time, the CCD trend has increased. In addition, variations between cities were more pronounced, showing a spatial pattern characterized by higher coupling levels in eastern/northern regions compared to western/southern regions. Our study can provide policy references for improving land planning, optimizing land use structures, and realizing high-quality, sustainable, green, and coordinated development in the YRDUA.