Classification of cities in the three regions.

The continuous development of industrial technology has led to significant environmental pollution and climate change, both of which have severely impacted human health. Investigating the coupling coordination between ecological environment quality (EEQ) and public health of residents (PHR) is beneficial for enhancing public health and promoting sustainable development. This study uses panel data from 55 cities within urban agglomerations of the Yellow River Basin, China (YRBC) from 2011 to 2022 to construct evaluation index systems for both EEQ and PHR. The entropy method is first employed to quantify the development levels of these systems. Subsequently, a modified coupling coordination degree (CCD) model is applied to evaluate the coordination between the two systems. Furthermore, the study utilizes the Dagum Gini coefficient, Kernel density estimation, and Markov chains to analyze the spatiotemporal evolution of CCD. The Quadratic Assignment Procedure (QAP) is finally used to empirically test the factors influencing regional differences in CCD. The findings reveal that both EEQ and PHR levels in the YRBC exhibited an overall upward trend during the study period, although PHR showed declines in certain years. The CCD demonstrated a steady increase across the entire sample and within all three major regions. Analysis using the Dagum Gini coefficient indicates a narrowing disparity in CCD, with the Gini coefficient decreasing from 0.0617 in 2011 to 0.0536 in 2022. Kernel density estimation suggests that the CCD distribution curve has shifted rightward, becoming higher and steeper, indicative of reduced absolute differences in coupling coordination levels. QAP regression analysis reveals that factors such as regional disparities in per capita GDP significantly influence CCD regional disparities.

工业技术的持续发展引发了严峻的环境污染与气候变化问题，二者均对人类健康造成了严重冲击。探究生态环境质量（Ecological Environment Quality，EEQ）与居民公共健康（Public Health of Residents，PHR）之间的耦合协调关系，对于提升公共健康水平、推动可持续发展具有重要意义。本研究选取中国黄河流域城市群（Yellow River Basin Urban Agglomerations，YRBC）55座城市2011—2022年的面板数据，分别构建生态环境质量与居民公共健康的评价指标体系。首先通过熵权法量化两大系统的发展水平；随后采用改进的耦合协调度（Coupling Coordination Degree，CCD）模型评估二者的协调程度。此外，本研究借助达古姆基尼系数（Dagum Gini coefficient）、核密度估计（Kernel density estimation）与马尔可夫链（Markov chains），分析耦合协调度的时空演化特征；最终通过二次指派程序（Quadratic Assignment Procedure，QAP）对耦合协调度区域差异的影响因素开展实证检验。研究结果表明，研究期内黄河流域城市群的生态环境质量与居民公共健康水平整体呈上升趋势，但居民公共健康在部分年份出现回落。全样本及三大主要区域的耦合协调度均实现稳步提升。达古姆基尼系数分析显示，耦合协调度的区域差距呈缩小态势，基尼系数从2011年的0.0617降至2022年的0.0536。核密度估计结果显示，耦合协调度的分布曲线整体右移，峰值更高且分布更趋陡峭，表明耦合协调水平的绝对差异有所降低。QAP回归分析证实，人均GDP区域差异等因素对耦合协调度的区域差异具有显著影响。