The synergistic effects of the digital economy and industrial ecologization on eco-urbanization in the Yangtze River Delta urban agglomeration

Digital-green fusion plays a vital role in advancing sustainable urban ecology. This study characterizes the levels of digital and green development through the digital economy (DE) and industrial ecologization (IEE), and explores their integrated effects on eco-urbanization (ECU). Using panel data from 41 cities in the Yangtze River Delta (YRD) region, we investigate the multidimensional spatio-temporal co-evolutionary patterns between the integration of digital economy and industrial ecologization (DEIEE) and ECU, while also uncovering the mechanisms through which DEIEE impacts ECU. The primary findings are as follows: (1) There exists a dynamic, bi-directional mutual promotion and response relationship between DEIEE and ECU in the YRD region. (2) From 2011 to 2022, there exhibits a synergistic increasing temporal correlation trend between DEIEE and ECU, with a predominantly positive spatial correlation in most cities. The positive spatial correlation intensity is found primarily in relatively developed cities, while negative correlation intensity is usually concentrated in underdeveloped cities. (3) A significantly positive spatial association with stable local transfer inertia and lock-in characteristics is found between DEIEE and ECU, with the HighDEIEE-HighECU type cities generally distributed in the developed southeastern cities of the delta region, while the LowDEIEE-LowECU type cities are relatively concentrated in the underdeveloped northern cities of the delta region. (4) DEIEE not only directly promotes ECU, but also indirectly advances it through enhanced environmental regulation, continuous green innovation, and efficient green finance. Moreover, ECU facilitates positive feedback promotion and spatial spillover effects on the integration of DE and IEE.