Assessing China’s basin-level water footprint through required sustaining land area

Abstract

Water footprint is a powerful tool for analyzing human activities’ impact on natural systems. Here we presented a first analysis that applied the concept of sustaining land area to water footprint assessments in China. Production-based and consumption-based water footprints were assessed using the multi-region input–output approach, and then compared with the water renewal rate to calculate corresponding required sustaining land area at the basin level. The results indicated that the total required sustaining land area to support water use was about two times the national territory size of China, pointing to unsustainable human water exploitation. Required sustaining land areas presented high heterogeneity within major basins. Basins in North China generally required a larger sustaining land area than the basin size. Most major basins in South China had sufficient water to support production, but their consumption-based sustaining land areas were larger than the basin sizes in receipt of virtual water from other basins. The developed methodology provides a complementary tool to the traditional volume-based water footprint method, with an additional merit of showing how human water exploitation matches/mismatches natural water renewal. The results have important implications for water management in a broad macro-economic context.

Keywords

• Environmental footprint
• Sustaining area
• Virtual water transfer
• Watershed
• Water use management