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April 30th, 2009
Via WaterWired, an interesting personal view from Dr. Chun Miao Zheng (founding director of the Center for Water Research at Peking University in Beijing) on the challenges facing an ever-drier China. As the article notes:
“…China is like two countries: dry in the north (Yellow River is here), where some areas have annual precipitation amounts under 200 mm (8 inches), and wet in the south (Yangtze River), where annual precipitation can exceed 1600 mm (64 inches). Sounds like the flip of California.
The north has more of the land, about 62%. The population is approximately evenly divided. Upshot: the south has 4x more water per capita than the north.
Right now, Dr. Zheng said that about 400 of the 660 cities have water shortages; 110 of those are classified as severe. About 90% of China’s aquifers are contaminated to some degree.
In 2030, China is expected to use 700-800 BCM annually, out of a total available of 800-900 BCM. Doesn’t sound real good, does it?
Dr. Zheng then spoke about the North China Plain, south of Beijing where the Yellow River flows to the sea. In that relatively small area – 140,000 square kilometers (54,000 square miles – slightly bigger than Arkansas), which is the economic, political, and cultural center of China – over 100M people live.
In this area, drastic declines in the groundwater levels have occurred, and the annual water budget deficit is abvout 4 BCM.
So what about the future? Some solutions being considered:
- Water savings
- Changes in agricultural practice (currently uses 60-70% of all water)
- Rainwater harvesting (30 M people currently)
- Desalination
- Price reforms
- “Ocean reservoirs”
- South to North water transfer
“Ocean reservoirs” are reservoirs constructed in the oceans where rivers flow to the sea, that separate salt and fresh water with membranes. The fresh water is then pumped back to the land. No, this is not a joke.
The big thing is the last item, a massive transfer from the wet south to the dry north. It is already underway, and consists of three routes: eastern, central, and western. The total amount of water to be transferred annually is about 45 BCM (37 MAF) in 2050. The cost will be about $US 60B (this figure seems low).
Keep in mind that the amount of water delivered in 2050 is only about 5-6% of China’s anticipated water use in 2030. That is barely a dent. All that fuss for 5-6%?
The western route is the most complicated, as it will involve tunneling in an area of complex geology, active tectonics, and great elevations. Three streams in this area will have 65-70% of their total flow diverted.
This massive project will have unimaginable environmental consequences. Dr. Zheng said that most of China’s endangered species lie in the western route region.
So will China run out of water? Dr. Zheng said that it won’t as a country, but that areas in the north and northwest are in trouble and already use every available drop.”