Where is the Yellow River?

The Yellow River is the second longest river in China and the cradle of the Chinese nation. The flow is 5464 kilometers, and the basin area is 752443 square kilometers. Kariqu at the northern foot of bayan har is the main source of the Yellow River. Its source is located at Yaradazi Peak in Bayan Kara Mountains, with an altitude of 4,675 meters and an average flow of 1.774.5 cubic meters per second. The dividing point of the upper and middle reaches is Hekou Town, Inner Mongolia Autonomous Region; The dividing point of the middle and lower reaches is Old Jin Meng. The estuary of the Yellow River is1500m wide, generally 500m, with a narrow part of only 50m and a water depth of 2.5m.. In some places, the depth is only 1.2 ~ 1.3 meters.

The Yellow River flows through Qinghai, Sichuan, Gansu, Ningxia, Inner Mongolia, Shaanxi, Shanxi, Henan, Shandong and other nine provinces and regions. Along the way, it gathers more than 40 main tributaries and tens of millions of streams and rivers, forming a rolling torrent, rushing for 5,464 kilometers, and pouring into the Bohai Sea in Kenli County, Shandong Province.

The Yellow River has the highest sediment concentration in the world. According to calculation, the middle reaches of the Yellow River receive about1.60 billion tons of sand every year. If these sediments are piled into an earth wall with a height of 1 m and a width of 1 m, it can circle the equator of the earth 27 times. The saying "a bowl of water, half a bowl of mud" vividly reflects this feature of the Yellow River. There is a lot of sediment in the Yellow River, which is caused by the serious degradation of forests, grasslands and cultivated land, soil erosion and land desertification caused by vicious development in many areas for thousands of years. Its watershed is the rainstorm area, and most of the banks of the middle reaches are the Loess Plateau. A large area of deep and loose loess, coupled with the serious destruction of surface vegetation, was washed away by heavy rain, and the surging flood carried rolling yellow sand into the Yellow River. Due to too much sediment in the river, the downstream riverbed is rising due to sediment deposition, and in some places, the bottom of the river has been higher than the ground on both sides of the river, becoming a "suspended river". Therefore, flood control of the Yellow River has always been a national event.

Before 1950s, the Yellow River often suffered from serious disasters such as floods and diversions. In the more than 2,000 years recorded in history, the lower reaches of the Yellow River were flooded by crevasses 1500 times, with 26 important diversions. The recorded lower reaches of the Yellow River generally pass through Hebei from Jinya River to the waters near Tianjin, which is called "the old road of Yu He River". From the first major diversion of the Yellow River in 602 BC to AD 1855, the current river course was changed. During this period, before 1 128, the Yellow River entered the sea from Tianjin and Lijin, and then went south to seize the Huaihe River. The disaster affected about 250,000 square kilometers of Haihe, Huaihe and the lower reaches of the Yangtze River. Every time a breach overflows, it causes great losses. There are 54 breaches in the lower reaches of 1933, with the affected area of1.65438+100000 square kilometers and the affected population of more than 3.6 million. 1938, the Kuomintang government blasted the Yellow River levee at Huayuankou, north of Zhengzhou, drowning 890,000 people, resulting in the famous Yellow River flood area.

The floods in the lower reaches of the Yellow River have always been concerned by the world. In history, there is a saying that the Yellow River burst its banks twice in three years and changed its course once in a hundred years. From the fifth year of King Ding Zhou (602 BC) to 2540 years of 1938, there were 543 recorded breaches, with more than 590 breaches/kloc-0, and the main channel experienced five major diversions and migrations. The flood reaches Tianjin in the north and Jianghuai in the south, including the Huanghuaihai Plain in Hebei, Shandong, Henan, Anhui and Jiangsu provinces, covering 250,000 square kilometers.

After the Opium Wars of 18 19 and 1840 in modern history, Kaifeng, Chenliu, Zhongmou, Lankao, Wuzhi and other places in the lower reaches of the Yellow River broke their banks many times, destroying farmland and villages, causing countless losses to the people.

After many investigations and repeated studies by scientists, the internal mechanism of channel changes of the Yellow River was revealed. It turns out that after the Yellow River was changed from Jiangsu to Shandong, it no longer affected the hydrological changes of the Huaihe River and Haihe River systems. However, for the Yellow River, a muddy river, its downstream flow range is very narrow, and its riverbed hangs high above the great plain. In addition, it is located in the mid-latitude zone with the most significant long-term fluctuation of climate and hydrology, and the middle and upper reaches of the Yellow River flow through the sand-producing area of the Loess Plateau with bare and loose soil. Once there are heavy rains and torrential rains, floods with high sediment concentration will be formed, and sometimes the maximum sediment transport peak can reach about 6 billion tons. When reaching the lower reaches of the Yellow River, because the lower reaches are controlled by the sea level, the topography of the great plains and the extension of the estuary, the slope is very gentle, the sediment discharge is obviously smaller than that of the middle and upper reaches, and the riverbed siltation speed is faster than that in the normal flood period. At the same time, due to the long-term river pattern in the lower reaches of the Yellow River, the Yellow River is blocked by hills and mountains in Shandong Province. Sudden flood with sediment often forms a river jam here, and its banks burst, so the river looks for new lowlands to form a river channel. It can be seen that the reasons for the diversion of the Yellow River are river siltation, suspended river height, poor river bank management and insufficient flood peak capacity.

Since the founding of New China, the state has invested a lot of manpower and material resources to transform the Yellow River, and the floods on both sides of the Yellow River have gradually decreased, and the former Yellow River flooded area has become a beautiful home for local people.