Changes of blue and green water in arid inland dissipation area based on coupled surface water and groundwater model

The Mainstream in the Tarim River Basin, Southern Xinjiang, China Climate change and human activities have significantly altered the water cycle, and water security evaluation and management are urgent. In arid and semi-arid areas, the assessment of blue and green water is particularly important. In this study, the MIKE SHE model is used to simulate the spatial and temporal changes of blue and green water resources in the mainstream of the Tarim River Basin (TRB) from 1990 to 2050 under land use and climate change conditions. The scarcity and vulnerability of blue-green water are introduced to evaluate the water security of the basin. The impacts of different land uses on blue-green water resources were also calculated according to the model zoning. The results indicate that from 1990 to 2050, blue water resources show a spatial pattern of gradual decrease from upstream to downstream. Compared to blue water, green water is dispersed more evenly over space. Future climatic scenarios will impact water security, as will changes in blue and green water security in terms of time and space. By comparing the influence of ecological water transport on the change of blue and green water before and after 2000, it was found that environmental water transport plays a certain role in improving the blue water scarcity in downstream of the TRB. The study is significant in maintaining regional water security and ecosystem stability. • The coupling model of surface water and groundwater is used to obtain the variation of the blue-green water. • Ecological water transfer enhanced the scarcity of blue water downstream of the TRB. • The spatial and temporal pattern of blue-green water scarcity in the study area was obtained. • Land use and climate change are considered while evaluating the blue- green water resources and water security.