A new method for evaluating the coordinated relationship between vegetation greenness and urbanization

Understanding and measuring the link between vegetation greenness and urbanization is crucial for public health and sustainable development. However, previous methods may oversimplify urbanization indicators and fail to adequately reflect changes in their relationships. To address this, we introduced a comprehensive urbanization vegetation coordination index (CUVCI) on the basis of comprehensive urbanization and a compound annual growth rate and applied this index to the Yellow River Basin in China. We examined the spatiotemporal evolution of the NDVI, comprehensive urbanization level (CUL), and CUVCI from 2000 to 2019 and explored potential driving factors. The results indicate that: (1) from 2000 to 2019, 87.8% of the areas in the Yellow River Basin demonstrated a trend of vegetation growth, with growth levels highest in the midstream regions, followed by the upstream and downstream areas. (2) The CULs of most cities in the basin have shown an increasing trend, with the CUL levels in the middle and downstream cities being significantly higher than those in the upstream cities. (3) CUVCI from 2000 to 2019 was characterized mainly by general coordination (57.4%) and minor conflict (18.5%), with minor-conflict cities located primarily in the middle and lower basin. The coordinating relationships in most cities show signs of improvement. (4) While natural environmental factors such as precipitation, temperature, and relief have a significant impact on CUVCI, scientific researchers can promote the coordinated development of vegetation greenness and urbanization. Our findings suggest that cities in the basin are experiencing economic prosperity and increased greenery. However, strong- and minor-conflict cities should prioritize cultivating and attracting scientific research talent and learning from coordinated provincial capital cities.