The integrated impact of climate and vegetation variation on blue and green water: A case study of the Jialing River Basin, China

Climate change exacerbates the imbalance of water resources allocation in the basin, and vegetation has an important impact on the regulation of water resources. The analysis of regulation mechanism of climate and vegetation changes on blue-green water resources could enhance water resources management within watersheds. Therefore, this study assessed the spatial and temporal characteristics of blue-green water resources by employing the Soil and Water Assessment Tool (SWAT) in the Jialing River Basin (JLRB), and explored the mechanisms of climate and vegetation changes on blue and green water resources in the basin thought correlation analysis and structural equation model. Draw conclusions as follows: (1) the whole basin showed a warming and humidifying trend from 1982 to 2020, under which the vegetation generally was getting green. (2) The basin had less blue-green water in the northwest and more in the southeast. There was a decreasing trend in both blue and green water from 1982 to 2000, and an increasing trend from 2000 to 2020. (3) The spatial distribution of blue-green water was uneven, and the annual average blue and green water was 369.03mm and 566.46mm, respectively. (4) In the context of basin warming and humidification, the change of blue-green water in the basin is mainly affected by precipitation. The regulation of blue and green water by vegetation greening could only weaken the impacts brought by climate change. The results of the study provide a solid scientific basis for water resource management in the basin.