第２篇∼∼
The position of the Yellow River basin is outlined in the map for East Asia on the right. It lies in approximate latitudes as the states of Virginia, Kansas, Nevada in North America, and countries like Greece and Turkey in the West.
The Yellow River, or Huanghe, is the second longest river in China. Tracing to a source high up the majestic Yagradagze mountain in the nation's far west, it loops north, bends south, and flows east for 5,464 km until it empties into the sea, draining a basin of 745,000 sq km, which nourishes 120 million people. Millennia ago the Chinese civilization emerged from the central region of this basin. [The Yellow River basin is outline in red.]
As the most heavily silt-laden river in the world, the Yellow River got its name from the muddiness of its water, which bears a perennial ochre-yellow color. The river is commonly divided into three stages. In the upper reaches, the river runs through mountainous and arid regions for 3,472 km, ending at Hekouzhen of Inner Mongolia just before it makes a sharp turn to the south.
Throughout history much of the river management effort had been devoted to improving the flood prevention capability of the levee-lined channel, with notable success in the period from 200 to 800 A.D. when the channel was kept to its course. But, keeping pace with an ever-rising channel bed was no easy task, and the protection offered by levees could at best be haphazard, especially at times of war. Historical records indicate a progressively frequent levee breaching in the last ten centuries. During such breaches, the flood water would rush onto the surrounding lands, not only inundating farmland and communities, but also taking over existing river channels. The devastated areas would be totally transformed even after the damaged levee sections were repaired and closed, flood water drained, and the river returned to its original channel.
[ 本帖最後由 ？ 於 2007-4-26 12:25 PM 編輯 ]
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