| ||||||||||||||||||||||||||||||||
|
Chinanews, Beijing, July 17 – The 2007 Yellow River water and sand diversion project was terminated recently. As sand from the river has been washed away into the sea, the riverbed is no longer blocked by sand, and water can flow through the riverbed more smoothly1. Since 2002, sand diversion task has been applied2 to the Yellow River six times, with 420 million tons of sand being diverted to the sea in total, the Yellow River Floods and Droughts Control Center said recently.
"If one wants to harness the Yellow River, one has to solve the sand problem first," as a popular saying goes in China. The Yellow River is said to be a river that contains the largest amount of sand in the world. In the old days, people used to say that 70% of the water in the Yellow River was filled with sand. It is estimated that every year, about 1.6 billion tons of sand are washed into the lower reaches of the river and 400 million tons of sand silted3 up in the riverbed, making the riverbed higher and higher. The riverbed “grows taller” at an average rate of 10 centimeters every year, finally making it a river floating high above the ground. If a flood occurs in the Yellow River, all the neighboring regions will be seriously affected4. The water and sand diversion project is aimed to solve this problem. In the water and sand diversion task, the water and sand in the Yellow River are first properly controlled in the reservoir and then diverted into the sea, making the riverbed clear again. Experiences show that water and sand diversion has become a proper way to solve the sand problem in the river. During the six times of water and sand diversion, about 420 million tons of sand have been washed into the sea in total. The main riverbed in the lower reaches has thus become clear. Before the task was carried out, about 1,800 cubic meters of water could flow through the riverbed per second; now, as many as 3,630 cubic meters of water can flow through in one second. The water and sand diversion project not only helps clear the riverbed, the fresh water flowing from the river also nourish the swamp areas nearby and enrich the biosystem there.
点击  收听单词发音
|
||||||||||||||||||||||||||||||||
TAG标签：
- 发表评论
-
- 最新评论 进入详细评论页>>
