Understanding advances and challenges of urban water security and
sustainability in China based on water footprint dynamics
Abstract
Sustainability of China’s numerous cities are threatened by both
quantity- and quality-induced water scarcity, which can be measured by
the water footprint from a consumption (WFcons) or production (WFprod)
perspective. Although WFcons was widely assessed, the changes in WFprod
of China’s cities were still unclear. Taking 31 major cities as
examples, this study revealed the dynamics of urban WFprod in China from
2011 to 2016. First, the spatiotemporal patterns of WFprod and water
deficit were evaluated and then the main reasons for the WFprod dynamics
and its implications for urban sustainability were explored. A
large-scale decrease in urban WFprod in China was found, with the
average WFprod decreasing from 13.8 billion m³ to 10.3 billion m³ and
the per capita WFprod decreasing from 1614.8 m³/person to 1184.0
m³/person (i.e., falling by more than a quarter in just six years). Such
shrinkage was particularly evident in drylands, eliminating the water
deficit in Xi’an and Xining. The reduction in grey WFprod caused by
implementing water pollution prevention policies and other relevant
measures played the most important role in the savings. In the future,
the implementation of updated pollution discharge standards is projected
to allow more cities to escape water deficits; however, the rapid growth
of the domestic and ecological blue WFprod caused by urbanization and
urban greening would destabilize this prospect. Thus, attention should
be given to both water pollution prevention and domestic and ecological
blue WFprod restriction to further alleviate urban water scarcity in
China.