Domestic Groundwater Depletion Supports China's Full Supply Chains

Groundwater use underpins much economic production. The unsustainable use of groundwater threatens environmental flows in surface waters, sustainable development, and future food security. The connection between agricultural trade and groundwater depletion has been recently highlighted, but how groundwater depletion supports the production of industrial and tertiary goods, trade, and consumption remains less well understood. Here, we present the first analysis of groundwater use and depletion embedded in the complete supply chain of China (including primary, secondary, and tertiary products). We use a multiregion input-output analysis coupled with the high-resolution groundwater use modeling to track groundwater depletion from production to end consumer. Our modeling results show that groundwater depletion occurred primarily in water scarce North China for agricultural production, but the depleted resource was then incorporated throughout the supply chain and dispersed across Chinese and international consumers. similar to 64 billion m(3) yr(-1) (+/- 1 billion m(3) yr(-1)) groundwater was depleted in China, in which more than a half was from Xinjiang, Hebei, Henan and Heilongjiang Provinces. Approximately 40% of the groundwater depletion can be traced to interprovincial transfer (21 billion m(3) yr(-1)) and export (4.8 billion m(3) yr(-1)). The hot spots for final consumption of groundwater depletion were major cities in both North and South China. Importantly, over 60% of the groundwater depletion was embodied in industrial and tertiary products for final consumption, highlighting the importance of tracing groundwater through the full economy. Groundwater depletion represents a long-term risk to supply chains, and policy-makers can use this understanding to sustainably manage groundwater and diversify supply chains.

Automated summary

Groundwater use is essential for economic production, but its unsustainable use threatens environmental flows, sustainable development, and future food security. This study analyzes the complete supply chain of China and finds that groundwater depletion primarily occurs in water scarce regions in the country, and a significant amount of depleted groundwater is incorporated into industrial and tertiary products consumed by major cities.