The reason why the Yellow River water is clear

The Yellow River water is unique for the following reasons:

I. Reasons

The "clear distinction" is mainly because the water quality of the two intersecting streams is different, and one of them is turbid, that is, the contents of particulate matter such as sediment, salt, organic matter and plankton are quite different. Particles in turbid water flow are surrounded by water molecules, forming particles with higher surface tension such as bubbles.

These particles adhere to each other, so that ordinary water molecules in another water flow can only adhere to the contact surface of the two water flows in the form of small molecules, and cannot be integrated into the closely adhered water flow, thus forming an obvious dividing line. From the point of view that the dividing line between the Atlantic Ocean and the Pacific Ocean is clear and straight, the adhesion of particles in the turbid current of the Atlantic Ocean is so great that even waves and ocean currents cannot easily break through this barrier.

However, with the precipitation of particles and the dialysis of their impurity components from high concentration to low concentration, they will eventually merge together.

Second, a brief introduction to the Yellow River

Located in the north of China, the Yellow River is one of the longest rivers in the world and the second longest river in China. The "yellow" of the Yellow River is actually sediment. The ancient book says: "The Yellow River fights water, and mud ranks seventh." 90% of the sediment of the Yellow River comes from the Loess Plateau, where the soil is loose and easy to erode and disperse. Whenever it is washed by heavy rain, it will lose a lot of soil and water and flow into the Yellow River.

The river basin is long in winter and short in summer, with large temperature difference between winter and summer and obvious seasonal temperature change. There is little precipitation in the basin, mainly dry land agriculture, which is dry in winter and spring, and the precipitation in summer and autumn is concentrated in July and August.

Geological influence and river course change

I. Geological impact

The gestation, birth and development of the Yellow River are controlled by geological processes in the geological history period, with tectonic movements caused by crustal changes as external forces and self-generated scouring, transportation and accumulation as internal forces.

In the historical process of becoming a river, it keeps moving forward and keeps pace with the times. Soil erosion in the Loess Plateau and sediment deposition in the lower reaches of the Yellow River began in prehistoric geological times, and have been increasingly influenced by human activities since then. According to various studies, the ancient Yellow River has three stages of development: the early Pleistocene from Tertiary to Quaternary is the gestation period of the ancient Yellow River.

The middle Pleistocene in Quaternary (1 1.5 million years ago) was the birth period of the ancient Yellow River. In the late Pleistocene (654.38+ 10,000 years ago ~ 654.38+ 10,000 years ago), the Yellow River formed a marine water system.

Second, the change of rivers.

In the historical period, the Yellow River has also evolved in the upper and middle reaches of the plain, and some of them have changed greatly. For example, the Hetao reach in Inner Mongolia, below Dengkou before 1850, is mainly divided into two tributaries, the northern branch is the mainstream, the Wu Jia at the foot of Yinshan Mountain, and the southern branch is the present Yellow River. 1850, the lower reaches of Wu Jia, north of Xishanzui, were blocked for about15km, and the south branch became the mainstream.

The north branch became the backwater channel of Houtao irrigation area. The river from Longmen to Tongguan also fluctuates greatly. However, the evolution of these reaches has little influence on the development of the whole Yellow River. The changes of the Yellow River mainly occur in the lower reaches.