Abstract
Quantifying the spatiotemporal distribution of water resources is still a key constraint on water resources management against the background of climate change and human activities. To investigate the interaction of climate variability and human activities on blue and green water scarcity (BW and GW-scarcity), the soil and water assessment tool (SWAT) model was used to simulate BW and GW-scarcity and its spatiotemporal distribution under scenarios of single or combined land-use change and climate variability. Multivariate statistical methods were used to identify the main factors affecting blue/green water and confirm the hot spots of water management. Taking the rapidly-developing Xiangjiang River Basin (XRB) in China as an example, where the urbanization rate increased from 42.15% in 2008 to 56.02% in 2018, the results showed that BW-scarcity was mainly affected by precipitation (r = 0.425) and population (r = −0.612), while GW-scarcity was mainly affected by agriculture (r = 0.429) and urban land (r = −0.593). The hot spot areas of blue and green water (BW and GW) shortage accounted for 29.7%, 4.6% and 3.4% of the total area in the lower reach, middle reach and upper reach of XRB, respectively. The rapid development of urbanization in the lower reach of the XRB caused serious shortage of BW and GW resources. This study would provide useful information for water resources management in corresponding human-water system. Future research should focus on how to optimize water resource allocation upstream and downstream of the basin.
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•Climate and land use change impact on blue/green water were quantified.•Multivariate statistical methods identify the main factors affecting blue/green water.•The growth of population and urban land is the main factor of water shortage.•The hot spot areas of water scarcity accounted for 37.7% of the total area in the XRB.