ABSTRACT:

Mexico is known to heavily rely on groundwater resources for the production of food commodities, and most of this production is located in water stressed regions. This study explores the embedded, or virtual, water in the agricultural goods produced in Mexico, tracking its changes over the period of 2007 to 2013 at a regional and county level. Using data sets on agricultural production obtained from Mexico’s government agencies and hydrometeorological datasets from the National Oceanic and Atmospheric Administration (NOAA), we applied previously established methods to estimate the water volumes allocated for crop production. We estimated the water footprint of crop production (WFP), per tonnage of production (WFUton) and per value of production in Mexican pesos (WFUpesos) for both rainfed and irrigated crops. We further subdivided irrigation into that provided by groundwater and that provided by surface water. The total water footprint of crop production (WFP) in Mexico for both rainfed and irrigated crops over the period of 2007-2013 averaged 1.61 X 10^11 m3 per year. The portion that comes directly from rainfall averaged 8.43 X 10^10 m3 per year and the portion from surface water and groundwater averaged 7.67 X 10^10 m3 per yr. Metrics related to irrigation with surface and groundwaters (i.e., blue water) use peaked during the 2011 drought, although the ratio of groundwater to surface water use stayed roughly the same. Additionally, in all but one year, the blue water volumes required by crops exceeded that reported by irrigation districts, implying some underreporting may be occurring. Although previous studies have quantified Mexico’s water footprint at the country scale, this is the first to our knowledge to address embedded water at the very fine county/municipio scale. This allowed us to identify the regions with high appropriation of freshwater resources for agricultural production and compare them to regions with ongoing groundwater depletion.