Regime Shifts in the Hexi Oases over the Past Three Decades: The Case of the Linze Oasis in the Middle Reaches of the Heihe River

Oases regime shifts in the context of integrated water resource management have a significant impact on ecosystem functions and services and affect regional sustainable development and human wellbeing. Taking the Linze Oasis in the middle reaches of the Heihe River as a case study, we evaluated the regime shifts of the oases over the past 30 years from the two perspectives of scale and structure, considering the structural diversity index (H), water savings (Cn), productivity (WP), and other indicators. Furthermore, the driving factors of the socio-hydrological processes and the corresponding effects of the regime stages were discussed. The results indicate that the oases expanded concurrently with the increase in the regional water consumption from 1.09 × 108 m3 to 1.93 × 108 m3. The production of low-water-consumption and high-yield crops was found to be the main cause for the oases structure’s adjustment. The regime shifts in the oases comprised three main stages from 1990 to 2020, based on the interaction of socio-ecological elements. Water management policies promoted the regime shift process, while economic factors determined the long-term shifts. The improvement in water-saving practices driven by economic benefits is an effective way to realize the sustainable development of the Hexi oases.