In addition to low per capita water resource available, the
distribution of freshwater resources is highly unbalanced in China.
North China (Supplementary material) accounts for 64% of the
national territory, but provides only 19% of the country’s available
water resources. Conversely, the Yangtze River watershed and
South China (Supplementary material) possess 81% of the total
national water resource (China land resources newspaper, 2010).
This imbalance has been worsened in recent years by increasing
population and improper water use that aggravate China’s regional
water shortage issues (Cheng et al., 2009). For example, only 58% of
freshwater met the quality criteria for safe drinking water in 2009
(Ministry of Environmental Protection of the People’s Republic of
China, 2009). For coastal seawater, areas with heavy human activities
(e.g., the Yangtze and Pearl River estuaries) are seriously
polluted with ammonia nitrogen, labile phosphate and petroleum
(Ministry of Environmental Protection of the People’s Republic of
China, 2009). Overall, water quality has become a great concern
for a country striving to sustain economic growth while preserving
sufficient safe drinking water supplies and the quality of its natural
inland and coastal waters.