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Keeping rivers flowing - a life's work

June 4, 2009
by Melinda Swenson

By all accounts, a trip down the Yangtze River in China below the Three Gorges Dam is more than a little harrowing. This river is fed by thousands of lakes and several mighty tributaries. In the gorge, the channel narrows to a few dozen meters, and the river rolls and roars, hemmed in by peaks that soar above 455 meters.

But when Chih Ted Yang, Colorado State’s Borland Professor of Water Resources, reminisces about his boat trip on the Yangtze, he describes the beauty of it. “It was humid, rainy, very green,” he says. “Through the mist you could see remnants of ancient temples clinging to the cliffs.”

International recognition

Yang has seen many rivers and holds them in high esteem. In some ways, he understands them better than anyone else in the world. A renowned expert in sediment transport and river morphology, he was awarded in 2008 the Prince Sultan Bin Abdulaziz International Prize for Water, the top prize in the category of surface water. He was chosen from more than 70 highly respected surface water engineers from throughout the world.

“I was very young when I published a formula for predicting how much sediment accumulates in a particular body of water and where it’s transported and deposited,” he says. “The formula was not well-received. It was against the tradition. The formula was very simple, and they were thinking, ‘If it’s too simple, it must not be good.’ I was asked to revise it, and I said ‘No.’

No water, no life

“Many engineers carried out independent verifications to see if it worked,” Yang says. “But it wasn’t until a decade later that the American Society of Civil Engineers reviewed all the formulas ever published and gave the formula the rating of No. 1 in the world.”

Yang, who received his master’s and Ph.D. at CSU, decided to enter the field of hydraulic engineering because he appreciates that water is the most important element in the universe. “Without it, there is no life,” he says. “When you fly into Egypt, you see nothing but desert. And then you fly over the Nile, and you see green clinging to the river, extending out about a mile.” He describes the liveliness inside this green border – people, agriculture, camels, and not far away, the dun-colored desert.

Sustaining rivers, reservoirs

It’s this respect for rivers that inspires Yang to work industriously to extend their life. Hydraulic engineers around the world use his theories to solve erosion and problems with sediment transport, which lends itself to the sustainability of rivers and reservoirs.

“Just 50 to 100 years ago, most of the reservoirs in the United States and in other countries were designed for a useful life of 5 to 100 years,” Yang said when he accepted his international prize in Saudi Arabia. “There is an urgent need to modify the design and operation of existing reservoirs for sustainable use and operation.”

Many years ago when Yang reached a fork in the road of his career and had to decide between structural engineering and hydraulics, he decided to study hydraulics. “Rivers are moving and dynamic, and that appeals to me,” he says. “Even if you walk a few meters up or down the same river, you will see it change. Rivers are here to meet the needs of society, the environment, wildlife, and humanity."


Original story by Melinda Swenson published in Colorado State Magazine, Spring 2009.