Impact of land development on the water-food-ecology nexus: Coupling coordination and interaction pathways in a coastal region of China

Understanding the coupling mechanism among key elements of nature-human systems is crucial for achieving sustainable development goals related to water, food, and ecosystem security in a changing environment. We developed an analytical framework integrating a comprehensive evaluation index, the coupling coordination degree (CCD) model, with the partial least squares structural equation model (PLS-SEM) to examine how land development influences the coupling coordination and interaction pathway of the water-food-ecology (WFE) nexus in Fujian Province, a coastal province significantly affected by human activity and climate change between 2000 and 2020. Results showed that land development intensified accompanied by increasing water consumption, slightly decreasing food production, and stable ecological status over the last two decades. Land subsystem integration reduced the synergy among elements of the WFE nexus, based on an overall decrease in the CCD, in these regions, integration of land subsystems reduced direct pathways within the land-water-food-ecology (LWFE) nexus, simplified interconnections, and reduced synergies in the nexus. The opposite was observed in highly urbanized areas, such as Xiamen, where the CCD increased, the integration of the land subsystem increased the indirect pathways within the LWFE nexus, increasing pathway complexity and synergies. Land development can both enhance and inhibit the coupling of key system elements depending on the urbanization level, suggesting that a one-size-fits-all approach is not effective. Our research offers valuable insights to inform sustainable development policies for the Fujian Province and other regions facing similar environmental and developmental challenges.