How to Ensure System Sustainability: Paradoxical Cognition and Adaptive Strategies for the Value Creation Process of Megaprojects

A megaproject is a complex technological-social-natural system, and its “double-edged sword” effect raises significant attention in research on system sustainability. However, prior studies often overlook the long-term characteristics of megaprojects, while paradox provides an effective lens for explaining their long-term evolution. Guided by a “context-cognition-action” analytical frame, this study employs an inductive and longitudinal case study approach to investigate the value creation process of a typical megaproject, focusing on paradoxical cognition, adaptive strategies, and core drivers of system sustainability. The findings reveal that “macro demand-tension cognition-adaptive governance” is an efficient pathway for value creation under dynamic contexts. Importantly, paradoxical cognition uncovers multi-level tensions (macro, meso, micro) in value creation, with a complex shift from a single layer to a nested structure as macro demands intensify. Correspondingly, adaptive strategies exhibit distinct logic: from reactive strategies to proactive strategies. This shift drives the evolution from the “Project–City–Environment” composite system to the “Project–City–Environment–Region” complex giant system. Furthermore, the evolution of responsibility is the core driver of system sustainability, characterized by a transition from intragenerational equity to intergenerational obligations driven by technological advancements. This study advances theoretical understanding of value creation and provides practical insights into the sustainable development of future megaprojects.