Abstract: Quantitative assessment of the correlation between natural capital utilization and high-quality development in Henan Province is of great significance for ecological protection and high-quality development in the Yellow River Basin. We constructed high-quality development index (HQD) and used it to quantify the development of each city in Henan Province based on the new development philosophy. We further employed the extended three-dimensional ecological footprint model to evaluate natural capital utilization. Spatiotemporal evolution of HQD and natural capital utilization during 2005-2023 was analyzed, and their correlation was further explored using the decoupling index and threshold regression model. Results showed that there was significant heterogeneity in HQD and each dimension scores across all the cities in Henan. Overall, HQD in western Henan was higher than that in eastern Henan, presenting a multi-layered decreasing pattern centered on Zhengzhou. Zhengzhou had the highest annual average HQD of 0.55, while the HQD value of Jiyuan was the lowest (0.22). All the 18 cities had the highest scores in coordination dimension and the lowest in innovation dimension. The maximum ecological footprint size (EF_size) was 2.64×10⁶ hm² in Zhoukou, and Jiyuan recorded the minimum of 1.80×10⁵ hm². Cropland, grassland, and construction land contributed substantially to EF_size, with the proportion of contribution from construction land increasing over time. Ecological footprint depth (EF_depth) of Xuchang reached a maximum of 8.68 while the minimum was 4.12 in Xinyang. Cropland and grassland accounted for relatively high proportions of EF_depth, while construction land made the smallest contribution. The relationship between HQD and EF_size in each city exhibited a significant inverted ‘U’-shaped curve, with the inflection point of multi-year average HQD at 0.43. HQD and EF_depth in the three cities of Luohe, Sanmenxia, and Xinyang showed a weak decoupling relationship, while the remaining 15 cities showed a strong decoupling during 2005-2023. The first-order lag term of HQD exerted a significant positive impact on current HQD. Both EF_size and EF_depth played a positive role in promoting HQD improvement, with a nonlinear trend of weakening from a strong initial state.

Key words: natural capital utilization, high-quality development, spatiotemporal evolution characteristic, threshold effect, Henan Province