Agricultural virtual water flows within the United States

Abstract

Trade plays an increasingly important role in the global food system, which is projected to be strained by population growth, economic development, and climate change. For this reason, there has been a surge of interest in the water resources embodied in international trade, referred to as ''global virtual water trade.'' In this paper, we present a comprehensive assessment of virtual water flows within the United States (U.S.), a country with global importance as a major agricultural producer and trade power. This is the first study of domestic virtual water flows based upon intranational food transfer empirical data and it provides insight into how the properties of virtual water transfers vary across scales. We find that the volume of virtual water flows within the U.S. is equivalent to 51% of international flows, which is slightly higher than the U.S. food value and mass shares, due to the fact that water-intensive meat commodities comprise a much larger fraction of food transfers within the U.S.. The U.S. virtual water flow network is more social, homogeneous, and equitable than the global virtual water trade network, although it is still not perfectly equitable. Importantly, a core group of U.S. States is central to the network structure, indicating that both domestic and international trade may be vulnerable to disruptive climate or economic shocks in these U.S. States.

The Hydro-Economic Interdependency of Cities: Virtual Water Connections of the Phoenix, Arizona Metropolitan Area

“…The database contains data on the FAF zone of origin (O) and destination (D) for 43 commodities. Commodities (C) are a more detailed categorization according to the Standard Classification of Transported Goods (SCTG), each of which fits underneath a water use category (i) corresponding to the United States Geological Survey (USGS) water use categories [38,39]. First, commodity production was summed by economic supercategory i and origin FAF zone O to arrive at total commodity production C for the FAF zone.…”

A framework for modelling the complexities of food and water security under globalisation

“…However, increasingly there are attempts to quantify virtual water flows within countries (Fig. 2b) (Dalin et al, 2014;Dang et al, 2015) and the water footprints of cities (Hoff et al, 2014). Identifying the fine-scale networks that constrain where water resources are extracted from the environment to meet remote demand is essential for managing water under globalisation.…”

“…Destination volume is indicated with links emanating from the outer bar of the same colour. Origin volume is indicated with a white area separating the outer bar from links of a different colour (taken from Dang et al, 2015).…”

Water Footprint of Cities: A Review and Suggestions for Future Research

“…The second approach uses empirical data on commodity transfers. For example, Dang et al [72] use Commodity Flow Survey (CFS) freight shipment data for the U.S. to determine virtual water transfers within the U.S. Due to the anomalous consumption characteristics of cities, it would be desirable to use empirical data on commodity transfers to quantify the WF of cities. However, this high resolution data is not available for all countries.…”

“…underlying the WF [35,73]. Additional information and examples of the application of network analysis to WF studies can be found elsewhere [71,[73][74][75].…”