Regional social-ecological system coupling process from a water flow perspective.

The social-ecological system is receiving more and more attention, and water resources have been a focal point for linking social systems and ecosystems, but how to clarify the regional social-ecological system coupling process through the water flow perspective and how to make ecosystem services management decisions still needs further research. This study integrates water quantity and quality and proposes a water-related ecosystem services flow framework. This study applied the framework to the Wuding River watershed and simulated water quantity and quality by SWAT model. The results showed that: (1) there is significant spatial heterogeneity in ecosystem service provisioning and meaningful improvement in water quality under the function of human-made capital in the green phase of the ecosystem services flow; (2) in the red phase, beneficiaries use the water supply for their production and life and discharge >7400 tons pollution loads into the ecosystem; (3) in this process, human-made capital reduces about 35 % of the ammonia pollution, and meanwhile, the ecosystem relies on its environment to further clean up about 44 % of the load. The research framework is suitable for watershed social-ecological systems with simplistic interactions, guiding ecological compensation schemes and related management policies. Furthermore, providing a scientific basis for the sustainable use of regional water resources.