Baseline Water Stress in China

The World Resources Institute (WRI)’s Aqueduct Water Risk Atlas, an online took that evaluates, maps, and scores water risks globally. Out of Aqueduct’s 12 indicators, Baseline Water Stress (BWS) is a score on water scarcity by measuring the ratio of local water withdrawal over available water supply, and is a good proxy for measuring water risks more broadly. Since Aqueduct’s BWS maps the water stress globally, it had to use data that are universally available. Even some countries have more detailed data, they were not used by Aqueduct. For example, Aqueduct BWS used one lump number for each country’s water withdrawal data. However, in China, water withdrawal data are available at the prefecture level of over 300 cities and towns. More detailed data at city-level can reveal more information (e.g. spatial patterns) that is lost in the lump country-level statistics. To recover the lost information, it is important to develop a BWS map for a country/region with more detailed data where they are available. In an effort to respond to this need, WRI has developed BWS China, a mapping tool that provides spatial analyses on baseline water stress in China. This Technical Note describes the data and methodology used to calculate BWS China, as an extension and localized module to the previous WRI’s publications on Aqueduct.

Overall results show Aqueduct BWS and BWS China share similar spatial patterns. However, when a closer look is taken at the catchment level, Aqueduct BWS and BWS China show differences at some catchments. More detailed data on water withdrawals by sector used in BWS China can reveal unobserved spatial patterns.