From regime shifts to adaptive cycles: dynamic understanding of human-water system

Human–water systems are constantly changing over time. Regime shifts encompass large, abrupt and persistent structural and functional changes, leading the system to new reinforced processes or feedbacks. While existing research focuses on detecting early warnings or measuring cascading effects under human-water contexts, less attention has been paid to how different regime shifts interact with varied spatial and temporal scales. Because any effort in water governance must be conducted within a specific spatiotemporal context, achieving fitness requires a deep understanding of cross-scale effects in the co-evolution of humans and water. We argue that many contemporary water governance challenges are originally homologous to those observed structures of feedback at smaller scales across history. Therefore, the theory of “adaptive cycle”, comprising the growth, conservation, release (reorganisation), and update phases, provides a staged evolutionary trajectory across nested social-ecological systems. Through this lens, we argue regime shifts occur during re-organisation phases and lead to scaling changes in feedback. We also emphasise that transitions (e.g., gradual water scarcity) and transformations (e.g., technological leaps) are ubiquitous. We suggest it is only possible to study the co-evolution of this system by adopting a deep-time perspective, which provides insights into how hydraulic technologies, basin-scale governance, and institutional path dependencies shape the long-term evolution of water management systems.