China's water shortage could shake world food security.

• Author: Brown, Lester R.
• Position: Includes related article on the issue of global food security - Cover Story

An abrupt decline in the supply of irrigation water to China's farmers has aroused growing concern in the world's capitals.

An unexpectedly abrupt decline in the supply of water for China's farmers poses a rising threat to world food security. China depends on irrigated land to produce 70 percent of the grain for its huge population of 1.2 billion people, but it is drawing more and more of that water to supply the needs of its fast-growing cities and industries. As rivers run dry and aquifers are depleted, the emerging water shortages could sharply raise the country's demand for grain imports, pushing the world's total import needs beyond exportable supplies.

Any major threat to China's food self-sufficiency, if not addressed by strong new measures, would likely push up world grain prices, creating social and political instabilities in Third World cities - as previous WORLD WATCH articles have pointed out (see box, page 12). New information on the deteriorating water situation has confirmed the imminence of this possibility. The challenge now facing the Chinese government is how to meet the soaring water needs of its swelling urban and industrial sectors without undermining both its own agriculture and the world's food security.

The decline in China's capacity to irrigate its crops is coming at a time when depleted world grain stocks are near an all-time low. With its booming economy and huge trade surpluses, China can survive its water shortages by simply importing more of its food, because it can afford to pay more for grain. But low-income countries with growing grain deficits may not be able to pay these higher prices. For the 1.3 billion of the world's people who live on $1 a day or less, higher grain prices could quickly become life-threatening. The problem is now so clearly linked to global security that the U.S. National Intelligence Council (NIC), the umbrella over all U.S. intelligence agencies, has begun to monitor the situation with the kind of attention it once focused on Soviet military maneuvers.

This deepening concern led the NIC to sponsor a major interdisciplinary assessment of China's food prospect. Headed by Michael McElroy, chairman of Harvard University's Department of Earth and Planetary Sciences, the study used information from intelligence satellites to refine cropland area estimates, and commissioned computer modeling by the Sandia National Laboratory to assess the extent of future water shortages in each of China's river basins. The recently released study concluded that China will need massive grain imports in the decades ahead - a conclusion that meshes with earlier projections published by WORLD WATCH.

Signs of Stress

Since mid-century, the population of China has grown by nearly 700 million - an increase almost equivalent to adding the whole population of the world at the beginning of the Industrial Revolution. Most of that population has concentrated in the region through which several great rivers, including the Yellow and the Yangtze, flow. Those rivers provide the irrigation water needed to grow much of the food for China, as well as the water for its burgeoning cities and industries.

This dependence has placed a growing burden on the region's land and water resources, because the Chinese population has not been able to expand into new land the way the Americans once did with their westward expansion into the Great Plains and California. In China, the western half of the country is mostly desert or mountains. The resulting concentration of Chinese population, industry, and agriculture has been roughly equivalent to squeezing the entire U.S. population into the region east of the Mississippi, then multiplying it by five.

A quarter-century ago, with more and more of its water being pumped out for the country's multiplying needs, the Yellow River began to falter. In 1972, the water level fell so low that for the first time in China's long history it dried up before reaching the sea. It failed on 1 S days that year, and intermittently over the next decade or so. Since 1985, it has run dry each year, with the dry period becoming progressively longer. In 1996, it was dry for 133 days. In 1997, a year exacerbated by drought, it failed to reach the sea for 226 days. For long stretches, it did not even reach Shandong Province, the last province it flows through en route to the sea. Shandong, the source of one-fifth of China's corn and one-seventh of its wheat, depends on the Yellow River for half of its irrigation water.

Although it is perhaps the most visible manifestation of water scarcity in China, the drying-up of the Yellow River is only one of many such signs. The Huai, a smaller river situated between the Yellow and Yangtze, was also drained dry in 1997, and failed to reach the sea for 90 days. Satellite photographs show hundreds of lakes disappearing and local streams going dry in recent years, as water tables fall and springs cease to flow.

The Fen river that runs through Taiyuan, the capital city of Shanxi province, no longer exists. The major river in the province, and the lifeline of Taiyuan, was emptied to fuel the city's coal industry. Big industrial wells driven more than 300 feet, and sometimes as much as 2,500 feet into the ground, tap Taiyuan's last remaining groundwater resources. Dan Goonaratnum, a water resources expert with the World Bank, notes that this city of 2 million "has come to the stage in which they either shift the population or divert water from the Yellow River," more than 200 miles away. Meanwhile, as water tables have fallen, millions of Chinese farmers are finding their wells pumped dry.

In the geography of water, there are two Chinas. The humid South includes the vast Yangtze River and a population of 700 million. The arid North includes the Yellow, Liao, Hai, and Huai Rivers, and has 550 million. While four-fifths of the water is in the South, two-thirds of the cropland is in the North. As a result, the water per hectare of cropland in the North is only one-eighth that in the South.

Although comprehensive hydrological data are not always available, key pieces of the water puzzle are beginning to emerge from various sources. A recent Chinese survey reported by Professor Liu Yonggong of China Agricultural University in Beijing indicated that the water table beneath much of the North China Plain, a region that produces some 40 percent of China's grain, has fallen an average of 1.5 meters (roughly 5 feet) per year over the last five years. A joint Sino-Japanese analysis of China's agricultural-prospect reports that water tables are failing almost everywhere in China that the land is flat.

In the late summer of 1997, many of the irrigation wells in Shandong Province, which was experiencing its worst drought in 25 years, were not pumping. Chinese water analysts report frenzied well-drilling in some provinces as farmers chased the falling water table downward.

Of course, those farmers' ability to provide food enough for their nation is constrained by a range of factors in addition to water - by the construction of roads over once-productive farmland, by erosion of soft, by the diminishing benefits of fertilizer, and by a shrinking backlog of the technology used to raise land productivity. But it is the swelling diversion of irrigation water, combined with heavy losses to aquifer depletion, that has emerged as the most imminent threat to China's food security.

Projected Demand for Water

Even as the Yellow River, aquifers, and wells get drier, the need for water continues to swell. Between now and 2030, UN demographers project that China's population will increase from 1.2 billion to 1.5 billion, an increase that exceeds the entire population of the United States. Even if there were no changes in water consumption per person, this would boost the demand for water by one-fourth above current levels - but per-person consumption, too, is growing. It is expected to grow in all three of the end use sectors - agricultural, residential, and industrial

In the agricultural sector, demand for irrigation water, now roughly 400 billion cubic meters or tons per year, is expected to reach 665 billion tons in 2030. As incomes rise, people are consuming more pork, poultry, beef, and eggs, and feed-grain use is growing. For example, to produce one kilogram of pork it takes four kilograms of grain, and one kilogram of chicken takes two kilograms of grain. More grain means more water [ILLUSTRATION FOR FIGURE 1 OMITTED]. According to the U.S. Department of Agriculture (USDA), between 1990 and 1997, consumption of pork climbed by a phenomenal 9 percent per year. Consumption of both beef and poultry, starting from a much smaller base, has climbed at over 20...