A holistic analysis of China's consumption-based water footprint (2012-2017) from a multilevel perspective

As the world's second-largest economy, rapid socioeconomic development in China has exerted unprecedented pressure on water resources. However, there is still uncertainty regarding consumption-based water footprint (CWF) assessment across different spatiotemporal scales, especially those differentiated by green, blue, and grey water footprints. To address this knowledge gap, this study employed a multi-regional input-output (MRIO) model and structural decomposition analysis (SDA) to quantify the spatiotemporal dynamics and key drivers of consumption-based green (GCWF), blue (BCWF), and grey (HCWF) water footprints in mainland China during 2012-2017. The main findings of the study are as follows. (1) The HCWF is approximately 4.4 times greater than the sum of the GCWF and BCWF, with water consumption caused by pollution significantly exceeding direct consumption. However, there was a significant decrease in all three CWFs after 2015, particularly HCWF. (2) The spatial distribution pattern of the CWF shows high values in the east and south and low values in the west and north, while virtual water (VW) transfer through commodity trade occurs mainly from inland to coastal regions. (3) The three highest water-consuming sectors were agriculture, food and tobacco processing, and construction, accounting for over 70% of the total water consumption. (4) Water efficiency and consumption patterns are crucial factors in reducing CWF, while affluence levels have the greatest impact on increasing CWF, followed by changes in industrial structure after 2015. Overall, the results of this study contribute to a comprehensive understanding of China's regional and sectoral water consumption throughout the supply chain. In addition, our findings identified regions and sectors with high water consumption and their drivers, which can inform policy decisions and contribute to synergistic cross-regional regulation and sustainable water resources management.