Sharon Wingfield, age 9, of Doswell, Virginia, for her question:

Why is the water of the Yangtze River yellow?

Ages ago, the people of China named it the Yangtze Kiang. Its name meant the Tongbdom River and later the same name came to mean the Great River. The Yangtze is indeed China's greatest river and one of the world's greatest rivers. Its network of streams and tributaies drains a region one fifth the size of our 50 states. Its waters rise high in the mountains of Tibet and its winding path meanders 3,100 miles to meet the sea. It flows into an arm of the Pacific Ocean called the Yellow Sea.

Much of the land through which it flows is covered with thick deposits of soft yellow clay

The Yangtze gathers tons of this siltish soil, adding a yellowish tinge to its water. Farther to the north, the great Hwang Ho river system meanders more slowly through similar deposits, washing away more of the yellow siltish soil as it goes. It is much yellower than the Yangtze and its name, Hwang Ho, means the Yellow River. North of the

Yangtze, the Hwang Ho empties its yellow mud into the Hwang Hai, alias the Yellow Sea.