The Role of Interregional Trade in Virtual Water on the Blue Water Footprint and the Water Exploitation Index in Brazil

Brazil is known for its abundant water supply. However, an uneven spatial distribution of water and strong concentration of economic activities has caused some regions to face water restrictions. The objective of this research is to identify the main water users in Brazil, in terms of virtual blue water, and the impacts of the water use pattern on the regional Water Exploitation Index. Among the main results, the hydrographic basin Tiet\^{e} was identified as the largest responsible basin for virtual blue water demand, while the hydrographic basin Litoral AL PE PB was an important virtual water supplier. Virtual blue water flows are largely interregional and a majority of the flows (66 percent) were exports from basins where the water balance indicates potential water restrictions. These results suggest that interregional trade in virtual blue water affects water availability for some Brazilian hydrographic basins, potentially undermining water security.