Water security assessment and analysis incorporating blue-green water in the river basin

In a changing environment, a comprehensive and accurate water security assessment is critical to regional sustainable development. Most water security assessment studies concentrate on the sustainable use of blue water and less on green water, while the latter is irreplaceable to sustain food production. Considering the vital role that green water plays in maintaining human production and ecosystem stability. Here we incorporate green water into the water security assessment framework, proposing a blue-green water security index (BGWSI) and conducting a case study in the Xiangjiang River Basin (XRB). Two main conclusions are as follows: (a) combining green water to improve the water security assessment framework. The framework expands and extends the connotation of water security assessment and pioneers linking the attributes of water resources, like natural, social, and spatial benefit distances. In this way, the intrinsic connection between human activities and the risk status of regional blue-green water security can be grasped more comprehensively. (b) The case study reveals that the framework is feasible and applicable. The index BGWSI can better reflect the influence of basin green water resource fluctuation, green water footprint dynamics, spatial distance, and other factors on the overall water security risk. Incorporating green water and its related concepts into the water security assessment framework would provide new insight into water security assessment research, and we hope it will provide a more comprehensive reference for conducting regional blue-green water security assessment research. Also, the framework would be popularized and applied in more similar areas of blue-green water security assessment studies, which may contribute to accurately identifying the actual status of regional water security and promote the development of more scientific water management measures.