Water resources transfers through Chinese interprovincial and foreign food trade

Carole Dalin, Naota Hanasaki, Huanguang Qiu, Denise Leonore Mauzerall, Ignacio Rodriguez-Iturbe

Research output: Contribution to journalArticle

116 Scopus citations

Abstract

China's water resources are under increasing pressure from socioeconomic development, diet shifts, and climate change. Agriculture still concentrates most of the national water withdrawal. Moreover, a spatial mismatch in water and arable land availability - with abundant agricultural land and little water resources in the north - increases water scarcity and results in virtual water transfers from drier to wetter regions through agricultural trade. We use a general equilibrium welfare model and linear programming optimization to model interprovincial food trade in China. We combine these trade flows with province-level estimates of commodities' virtual water content to build China's domestic and foreign virtual water trade network. We observe large variations in agricultural water-use efficiency among provinces. In addition, some provinces particularly rely on irrigation vs. rainwater. We analyze the virtual water flow patterns and the corresponding water savings. We find that this interprovincial network is highly connected and the flow distribution is relatively homogeneous. A significant share of water flows is from international imports (20%), which are dominated by soy (93%). We find that China's domestic food trade is efficient in terms of rainwater but inefficient regarding irrigation, meaning that dry, irrigation-intensive provinces tend to export to wetter, less irrigation-intensive ones. Importantly, when incorporating foreign imports, China's soy trade switches from an inefficient system to a particularly efficient one for saving water resources (20 km3/y irrigation water savings, 41 km3/y total). Finally, we identify specific provinces (e.g., Inner Mongolia) and products (e.g., corn) that show high potential for irrigation productivity improvements.

Original languageEnglish (US)
Pages (from-to)9774-9779
Number of pages6
JournalProceedings of the National Academy of Sciences of the United States of America
Volume111
Issue number27
DOIs
StatePublished - Jul 8 2014

All Science Journal Classification (ASJC) codes

  • General

Keywords

  • Environmental policy
  • Sustainable agriculture
  • Trade policy

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