Why is the Yellow River water in China gold?

The Yellow River is considered a "Chinese fear" that is yellow due to the sediment amount of tens of times normal.

For a long time, the Yellow River (Yellow River) is considered a fear of China because it often causes serious flooding. This is the sixth longest river in the world and the second longest in China. The river basin is the birthplace of Chinese civilization, deposited by most of the sediment from the West Plateau in the west, according to SCMP.

An international team of scientists said alluvial flooding in the river for a long time gave the river a characteristic yellow color. Sediment is also the reason why the river often breaks its banks.

Based on the new findings, scientists are studying ways to improve planning, construction and management of river engineering projects in China and abroad.

Alluvial flooding on the river for a long time has given the river a characteristic yellow color.

The new study, led by Professor Hongbo Ma, of the Earth Sciences department at Rice University, Houston, Texas, is the head of the research, published in the journal Science Advances on 12 May. Accordingly, Hoang Ha River transports sediment levels 10 - 20 times higher than the limits described by modern material models.

Because the silt itself is small, fine particles, it means that they can travel a long distance by only creating minimal friction when interacting with water, river banks and riverbeds.This large amount of silt makes the river yellow.

"In rivers with characteristic low-lying sand - like Amazon, Mississippi - only about 40 to 60 percent of the energy used to transport sediments downstream , " said Jeffrey Nittrouer, a researcher at Rice University. know . "In the Yellow River, more than 95% of the energy used to transport sediment ".

The physical properties of silt are not properly understood in river science, partly because few rivers in the world have many such sediments like the Yellow River. Researchers have developed a new alluvial motion model that they consider useful for flood management projects.

The Chinese government has built many dams on the river for years to try to reduce flooding. Since 2002, these dams once a year have to discharge a large amount of freshly washed sediment.

This method proved effective in the early years. However, recent research shows that dam construction is no longer a suitable way to manage rivers because they reduce the ability to transport sediment by trapping most of them in reservoirs.

"On the surface of the river is almost fine sand, very suitable for transportation. But in recent years the riverbed has become rough because larger and heavier particles are deep down, forming a protective layer" , Wu Baosheng, one of the study's authors, from Tsinghua University's Department of Hydraulic Engineering, said.

This discovery adds to the debate about the dam, starting with the problems arising at the Three Gorges Dam in Henan Province, the first dam built on the Yellow River in the 1960s, forced to again because silt builds up sediment in the reservoir. The problem is recurring even after redesigning and some of the top engineers have called for breaking the dam.

Researchers believe that the new sediment motion model will clarify this debate.

"The impact of building or dismantling a dam on sediment transport and channel stability can be assessed with our new alluvial transport model and previous knowledge about particle size distribution of sediment layers , ' the authors stated.