Ecological Damage Swells China’s Floods : Asia: Development and logging leave Yangtze region vulnerable to rains.

Zhang Manyiu, mayor of this small village on the banks of the Yangtze River, wades through floodwaters in his underwear, his trousers slung over his shoulders. On dry land, he quickly pulls on his pants before greeting visitors, zipping his fly between handshakes.

“This is the worst flood this century,” he says, gazing at the inundated red-tile roofs of his village. “In 1954, the water was this high . . .” he says as he gestures to his waist. “In 1983, it was this high . . .” he says as he raises his hand to his shoulder. “And now . . .” His hand hovers in front of his face and rises. “It’s getting worse and worse.”

The Yangtze is China’s longest river, winding from rugged Qinghai and Sichuan provinces in the west to Shanghai, “the dragon’s mouth,” where the muddy river empties into the East China Sea. Every year, the river overflows when Himalayan snows melt and the summer rains come. Houses flood, farmlands wash away and millions of Chinese are left homeless. This year, a combination of torrential rains and an early thaw has created a record-breaking deluge that has killed at least 1,200 people--and experts fear it is not over yet.

But, they say, what has worsened the flooding this year and in recent years is the environmental damage caused by China’s pell-mell economic development. Widespread logging near the source of the river, poorly planned agricultural use and rampant industrialization has caused massive erosion in China. Rivers such as the Yangtze and the Yellow--also known as “China’s Sorrow” for the devastation its overflows have caused--are filling with silt and are flooding more easily than ever.

How Man Wong, an explorer and conservationist from Hong Kong, who has traced the Yangtze to its source, says it is there in Sichuan province where the Chinese can find the origins of some of the human-created problems that expose China to ever-worsening floods.

Mass tree-cutting in Western Sichuan, on the edge of the vast Himalaya mountain range, has reduced the protective canopy of leaves and the extensive, land-stabilizing root network that keeps soil from washing away in the rain, he and others say.

One result has been worsening droughts and dust storms in Western China, including a severe dry spell this year.

Another harmful effect: the heavy volume of silt and sand flowing downriver, adding layers to riverbeds and filling up lakes and reservoirs. Almost 90% of the lakes along the Yangtze have disappeared, leaving fewer places to absorb the river’s overflow, and industrialization has compounded the problem. “I wouldn’t attribute the floods solely to the siltation,” says Wong, “but it makes the difference between a flood and a disaster.”

Rivers such as the Yangtze and the Yellow expose the huge populations that live alongside them to recurrent disaster. The government has sought to contain the problem--undertaking, for example, the highly controversial $20-billion Three Gorges hydroelectric dam on a scenic stretch of the Yangtze--but admits that its management has gotten out of control. On a May visit to the river regions before the rains began, Vice Premier Jiang Chunyun criticized local flood prevention and safety measures, warning of the potential for serious damage.

The warning was prescient but too late. “You can’t prepare for a flood of this magnitude,” says Vaclav Smil, a University of Manitoba professor who specializes in China’s environment. “The river is a living creature and can’t be harnessed.” There is a precarious balance, he notes, in living with the river.

The captain of a barge, taking time out during the floods to repair his vessel, knows firsthand what happens when this delicate situation gets out of kilter. “The river has much more sand than before, sometimes so much a boat can’t go through,” says the captain, who identifies himself only by his surname, Zhang.

Since the rains started more than 40 days ago, the environmental costs have mounted. The floods have ruined 2.7 million acres of crops in 10 provinces and caused estimated losses of $4.4 billion, according to early figures.

And while flood response has improved over the years--as many as 3 million people may have perished in the 1954 flood--the floods themselves are bound to get worse for many, experts say.

“It’s that eternal dilemma,” Smil says. “People shouldn’t be living in certain places--on earthquake faults or on flood plains. But they do, and there are consequences.”

The confluence of natural hazard and economic development is plainly visible in Jiujiang, a Yangtze port just across from this village. City authorities have built a special economic zone, complete with hydroelectric power station, right in the flood plain. Today, the zone has escaped a damaging deluge--but only because it’s behind a dam that local engineers have been working frantically to maintain.

Thousands of soldiers, farmers and workers are racing to extend another dam that protects the city, which lies lower than the river. Located at the intersection of the Yangtze and China’s main north-south railway, Jiujiang normally is a bustling commercial hub. Almost its entire economy--fishing, agriculture and transportation--relies on the river’s bounty.

But now that very industry is threatened by the water that usually sustains it.

With the trains and boats stopped, men are rescuing stranded neighbors and villagers; there are reports that tens of thousands of flood refugees are jamming the city. Every family must send one member to join around-the-clock shifts bagging sand to bolster earthen dikes.

“Over 30 dams have broken,” says a weary Jiujiang official. “Right now we’re just trying to save the city.”

Not many people downriver think about how a tree falling in Tibet may be partly responsible for their houses being underwater; as the sun appears for the first time in weeks, ever practical, the Chinese here are just thinking about doing their day’s chores.

Gui Chunbo, a boatman who has lived within sight of the Yangtze all his life, says he would not move, even though water has nearly filled the first floor of his two-story brick house.

“I could see the water coming closer, day by day, from my window,” he says. “So we just moved all our furniture upstairs and waited.”

As he poles his small wooden boat to his house, he waves to a neighbor who is floating on two inner tubes lashed together, hanging her laundry on a telephone wire. Another neighbor is setting up a fishnet where the road once ran.

“If it rains again this week, we will be in real trouble,” Gui says. “But we are river people, and we have no place else to go.”