Erosion Control
December 20, 2005

In China, the world’s largest dam impounds floodwater, but without other controls, erosion will persist.

The initial reason to sign on a six-day cruise up China’s Yangtze River was the scenery, which in itself would have been enough, given that most of what we saw will soon be lost. Almost half of our 1,352-km (840-mi.) voyage was to have been in the Three Gorges, where the Yangtze rushes through 914-m (3,000-ft.) limestone cliffs, some so narrow and steep it’s said sunlight never reaches the water. Hidden shoals and treacherous currents are so numerous that ships must navigate 37 one-way channels. Once on the water, it was easy to lose track of the scenery and become distracted by the functional problems of containing this unruly river, especially in light of the controversy surrounding the Three Gorges Dam, the Chinese government’s latest and most massive attempt to control this mighty river, which has created havoc in central China for centuries. The Yangtze is China’s longest river, the third longest in the world after the Amazon and the Nile and the third largest in terms of runoff after the Amazon and the Congo. The Yangtze gives with one hand what it takes away with the other, depositing rich soil in its delta but causing devastating floods in its vulnerable middle reach. In the 2,200 years of Imperial rule that ended with the Qing Dynasty in 1911, the Yangtze has caused 214 major floods, on average one every 10 years. The last century began with the dual flooding of the Yangtze and the Han rivers in 1911, which was followed by four major events: in 1931 almost 150,000 lost their lives when an area the size of New York state was inundated and 3 million ha (7.4 million ac.) of farmland were ruined; 142,000 people died in a flood four years later; in 1954, another 40,000 lost their lives and floodwaters suspended operations of the railroad between Beijing and central China for four months; and when the river rose in 1998, 3,000 people died, 5 million homes were lost, and 21.8 million ha (53.9 million ac.) of farmland were submerged for a damage total of $30 billion.