The Yellow River, the fifth longest river in the world, is a 5464-kilometer-long river winding in the north of China. Seen from high altitude, it looks like a huge "auspicious" and is a unique totem of our nation.
Second, the characterization of the Yellow River
Not only the big river, the yellow river, the yellow land, the emperor and the yellow skin. All these yellow features sublimate this turbid stream flowing through the heart of China into a sacred river. Hanshu Gully records that the Yellow River is the first of all waters: "China has hundreds of sources, so it is not a matter of four blasphemies, and one river is a Sect."
Third, the theory of loess weathering.
In the long geological time, in the desert Gobi in the inland of Asia, the sand everywhere was decomposed and crushed in the harsh environment of sudden cooling and heating until it formed powder. The northwest airflow prevailing in the inland has blown them to the east for many years, and the coarse sand has fallen on the Mongolian plateau. The most delicate powder fell to Gansu, Shaanxi, Shanxi, Qinghai, Ningxia and Henan provinces with the wind today. After millions of years of transportation and accumulation, a Great Wall from north to south has finally formed.
Fourth, the deep and vast loess layer.
This is an unparalleled loess, with an area of 4 1000 square kilometers, and the thickness of loess coverage is generally above 100 meters. The loess depth in Longdong, Shaanxi and Shanxi is 100 to 200m, and the thickness in Lanzhou is over 300m.
The Garden of Eden five or six thousand years ago.
Botanists have found that although the rainfall in the Loess Plateau is not as abundant as that in the south, the leaching loss of nutrients is also less, which is very suitable for the growth of poplar, birch, oak, Pinus tabulaeformis, spruce, Zizyphus jujuba and Vitex negundo. At that time, lush vegetation cultivated a warm and rainy Eden. Today, there are large areas of virgin forests in Shanxi, Shaanxi, Gansu and Ningxia. Henan Province, located in the Central Plains, is called "Yu".