Evaluating the evolution of oasis water metabolism using ecological network analysis: A synthesis of structural and functional properties

Abstract The sustainable use of increasingly strained water resources is a critical challenge for oases with dry climates, fragile ecosystems, and developing economies. Knowledge of how best to manage these resources should be pursued from a holistic perspective considering the multidimensionality of human-nature water cycles. Thus, we built an integrated evaluation framework of oasis water metabolism (OWM) by incorporating the water-related benefits into the structural analysis of the flux network. On this basis, we established a water configuration network model by fully considering the hydrologic attributes and functioning of oasis components. Novel indicators were designed to represent the effectiveness of the OWM, and sensitivity analysis was used first to investigate the system response to the flux changes. Finally, we examined the changes in the water metabolism effectiveness and structural fitness from 1990 to 2015 through a case study of the Keriya Oasis, a typical arid oasis in Northwest China. Our results indicate that the water flux structure of the Keriya Oasis has become robust, with increasing resilience and declining efficiency, while the water-related benefits have substantially declined. The new insights gained are that the structural robustness does not represent the functional effectiveness, and thus, coupling them is essential for a water metabolism assessment. The OWM’s functional deterioration, albeit its structural fitness, has critical long-term consequences for the sustainability of the oasis. Accordingly, water configuration alternatives were explored to improve functional effectiveness without sacrificing structural balance.