Spatiotemporal evolution and driving factors of water footprint in the Yellow River Basin based on multi-regional input-output and LMDI models

Water resources are the key resources for ecological protection and high-quality development in the Yellow River Basin. As a key indicator for measuring the pressure on regional water resources utilization, the water footprint can comprehensively reflect the status of water resources utilization in the Yellow River Basin. Therefore, analyzing the spatiotemporal patterns of water footprint, inter-regional transfer characteristics, and the driving factors of water footprint changes can provide a scientific basis for the formulation of policies to improve the level of water conservation and intensive utilization in the whole basin region. The paper constructed a multi-regional input-output model of water resources at the prefecture-level city scale to examine the spatiotemporal patterns of water footprint in the Yellow River Basin and the transfer characteristics of virtual water footprint among cities in 2012, 2015 and 2017. The Logarithmic Mean Divisia Index (LMDI) model was used to further explore the socio-economic drivers of changes in the water footprint and their impacts. The research finds that the water footprint in the Yellow River Basin shows an overall inverted "U"- shaped evolution trend of first increasing and then decreasing over time, and presents a regional pattern of "higher in the middle and lower reaches and lower in the upper reaches" in space. The transfer of water footprint is mainly concentrated within the provinces, and has obvious economic gradient-oriented characteristics. The level of economic development and technological factors are the main drivers of the change of water footprint, and there is significant spatial heterogeneity in the impacts of these factors on water footprint. Based on the differences in the mechanisms, the 78 cities are divided into five categories of water footprint driving patterns, providing a scientific basis for region-specific policies and targeted improvements in urban water conservation efficiency within the basin.