1. Global Warming--With the intensification of global warming in recent years, on the one hand, it makes the evaporation of the river increase greatly, and on the other hand, the upstream glaciers in spring and summer absorb a lot of heat by melting, which results in the inland local temperatures being lower than usual, and the temperature difference between the inland and the ocean is reduced. This reduces the temperature difference between the inland and the ocean, which in turn causes the monsoon to weaken and lacks the water vapor that the monsoon brings into the inland from the sea. Although the melting of glaciers due to global warming has increased the flow of water from upstream sources, it has not been able to offset the effects of increased evaporation and weakened monsoons. The result is that the amount of water in the middle and lower reaches of the river decreases every year.
2. Destruction of vegetation - the Loess Plateau region is seriously damaged by vegetation, the lack of vegetation to support the gradual desertification of the land, evaporation becomes higher, the land is dry and groundwater needs to be constantly absorbed by the flow through the river in order to replenish.
3. Backward irrigation methods - the upper and middle reaches of the Yellow River flow through the less economically developed old, small, border and poor areas, lack of water-saving irrigation technology and funds, mostly flood irrigation, the Yellow River water is seriously wasted.
① the upper reaches of the arid and semi-arid zone precipitation rate class less, the middle reaches of the main recharge area but serious soil erosion, seasonal variations, the lower reaches of the basin area is small, less recharge;
② the basin of the population is growing fast, the population growth rate is far more than the growth rate of food;
③ in recent decades, with the development of society, the Yellow River coastal industries and urban water consumption continues to grow, the diversion of the Yellow River irrigation area continues to expand, the Yellow River irrigation area is expanding. The area of irrigation from the Yellow River has been expanding;
④ The reservoirs have a low regulating capacity, and the management of water resources is not uniform;
⑤ The water charges are cheap, and the low price of water can not arouse people's awareness of water conservation, and the industrial and agricultural water use is extremely wasteful;
⑥ The environmental pollution drastically reduces the utilization rate of the Yellow River water.
Suspended River
Due to siltation, most sections of the 5464-kilometer-long Yellow River, the riverbed is higher than the cities and farmland in the basin, and is restrained by the embankment, which is called the "Suspended River". So where did the Yellow River start to become a "hanging river"?
Dengkou County, southwestern Mongolia Bayannur League, where the Yellow River channel than the county seat an average of 4 to 6 meters higher.
The Yellow River runs between the Zhongtiao Mountains and the Qinling Mountains, traveling east through Henan Mengjin. From here, 30 kilometers from the Yellow River, is China's famous capital city of Luoyang. Luoyang is one of the eight ancient capitals of China. Since the Eastern Zhou Dynasty, there have been the Eastern Han Dynasty, Cao Wei Dynasty, Western Jin Dynasty, Northern Wei Dynasty, Sui Dynasty (Emperor Yang), Tang Dynasty (Wu Zetian), Later Liang Dynasty, Later Tang Dynasty and other dynasties built their capitals here, which is known as the "Nine Dynasties Ancient Capital".
After the destruction of Yin, the nine tripods, the national treasure, were moved to Luoyang, the capital of Luoyang. When King Wu died, the two dukes, Zhou and Zhao, who assisted King Cheng at that time, created Luoyi on a large scale, establishing two cities, Wangcheng and Chengzhoucheng, respectively. The one between the east and west of Jianshui is Wangcheng, which is the area of Wangcheng Park in Luoyang, Henan Province, and the one east of the Jianshui, which is near the present-day Baima Temple, is Chengzhoucheng. King Ping of Zhou moved his capital to live in Wangcheng, and King Jing of Zhou moved his capital to Chengzhou City. After Liu Xiu became emperor of the Eastern Han Dynasty, he built the capital of Luoyang.
The city of Luoyang in the Han and Wei dynasties was expanded on the basis of the ruins of Chengzhou City. The city of Luoyang was nine miles and seventy paces from north to south, and six miles and ten paces from east to west, so it was also known as the "City of Nine and Six".
As early as 5,000 to 6,000 years ago, 50 miles west of Luoyang, "Yangshao culture", it can be seen at that time the matriarchal clan communal system is quite developed. This is the beginning, more and more brilliant.