Water resources transfers through Chinese interprovincial and foreign food trade
Open Access
- 23 June 2014
- journal article
- Published by Proceedings of the National Academy of Sciences in Proceedings of the National Academy of Sciences of the United States of America
- Vol. 111 (27), 9774-9779
- https://doi.org/10.1073/pnas.1404749111
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.Keywords
This publication has 17 references indexed in Scilit:
- Evolution of the global virtual water trade networkProceedings of the National Academy of Sciences of the United States of America, 2012
- China’s water–energy nexus: greenhouse-gas emissions from groundwater use for agricultureEnvironmental Research Letters, 2012
- MIRCA2000—Global monthly irrigated and rainfed crop areas around the year 2000: A new high‐resolution data set for agricultural and hydrological modelingGlobal Biogeochemical Cycles, 2010
- Circos: An information aesthetic for comparative genomicsGenome Research, 2009
- Environmental implications of urbanization and lifestyle change in China: Ecological and Water FootprintsJournal of Cleaner Production, 2009
- An integrated model for the assessment of global water resources – Part 1: Model description and input meteorological forcingHydrology and Earth System Sciences, 2008
- An integrated model for the assessment of global water resources – Part 2: Applications and assessmentsHydrology and Earth System Sciences, 2008
- Historical Trends in China's Virtual Water TradeWater International, 2007
- Water saving through international trade of agricultural productsHydrology and Earth System Sciences, 2006
- Virtual versus real water transfers within ChinaPhilosophical Transactions Of The Royal Society B-Biological Sciences, 2005