Based on the global water-risk indicators from World Resources Institute’s Aqueduct Water Risk Atlas (Aqueduct), a weighted aggregation methodology was applied to bring Aqueduct’s catchment-level information up to the country and river basin scales. This methodology addresses each of the challenges by starting with indicators that were computed within basic hydrological units and assigning spatially explicit weights to reflect the importance of the specific areas based on where water is being used. From these calculations, estimates of the average level of exposure to 5 of Aqueduct’s physical water-quantity risk indicators were generated for all countries and major river basins worldwide. These indicators include (1) baseline water stress: the ratio of total annual water withdrawals to total available annual renewable supply; (2) interannual variability: the variation in water supply between years; (3) seasonal variability: the variation in water supply between months of the year; (4) flood occurrence: the number of floods recorded from 1985 to 2011; and (5) drought severity: the average length of drought times. Resource Watch shows only a subset of the data set. For access to the full data set and additional information, see the Learn More link.
Aqueduct Country and River Basin Rankings
These global indicators are best suited for comparison among countries and major river basins to help companies, investors, and governments assess water-quantity-related risk at the country and basin scales, because of the inherent limitations in trying to simplify complex phenomena into a single number. Where available, more detailed, locally sourced data should be preferred for assessing water-related risks and supporting decision-making processes. Information is lost when aggregating indicators from a smaller scale. Many countries, such as the United States, and river basins, such as the Ganges-Brahmaputra, are large enough to span multiple climatic zones, and the process of averaging indicator values can disguise regions with very low or very high water-related risks. These indicators measure the underlying factors that drive water-quantity-related risks across countries and river basins, and are not designed to capture the effects of governance regimes, water quality, or investments in water-availability solutions. Resource Watch does not display complete data set.
Gassert, F., P. Reig, T. Luo, and A. Maddocks. 2013. “Aqueduct Country and River Basin Rankings: A Weighted Aggregation of Spatially Distinct Hydrological Indicators.” Working paper, November. Washington, DC: World Resources Institute. Available online at http://wri.org/publication/aqueduct-country-river-basin-rankings. Accessed through Resource Watch, (date). www.resourcewatch.org.