There is also a river in the north of Bayan Kara called Weak Water. According to the historical records, "Dayu drew weak water to the stand, and aftershocks entered quicksand." In ancient times, weak water was also called stand out Aquarius. In the Han dynasty, according to its description, the river that originated in Qinghai and flowed into Alashan was called weak water. This river has many names, such as HeAquarius, Qianggu Water, Fresh Water, Overlying Water, Auxiliary Water, Zhangye Water, Ganzhou River and Heihe River. At present, this river still retains many ancient names. According to textual research, the ancient weak water is Shandan River, a tributary of Heihe River, and the upper reaches of Heihe River are called Ganzhou River in ancient times. The northern section of the modern Shandan River after it joins the Heihe River is still called weak water. Weak water crossed Mount Li into Inner Mongolia in ancient times, which was called Heihe River, which was related to the black water city of Xixia.
Strangely, Heilongjiang in the northeast has a similar name. Heilongjiang is the third longest river in China, which was called "black water" and "weak water" in ancient times, and was called "Heilongjiang" only in Liao Dynasty. In fact, Heilongjiang and Blackwater are the same meaning. "Heilongjiang is dark and winding like a dragon, hence its name." Today there is Heihe River along the coast of Heilongjiang, which is an ancient name.
Why Heishui River in Gansu and Heilongjiang in Northeast China were once called Weak Water and Heihe River is puzzling. However, Bian Xiao made an amazing discovery when reading the topographic map of East Asia. It turns out that there is a long "canyon" between Hulunbeier Lake and Juyanhai, which is located inside the Mongolian Plateau and close to the border between Inner Mongolia and Outer Mongolia. Its altitude is lower than the plateaus on both sides, so it may not be a canyon now.
Imagine that in ancient times, the climate was very warm and the rainfall was abundant, and there was a lot of glacier snow water in the northwest. In this way, the weak river originating in Qinghai is abundant, and the environment in Alashan has not deteriorated, so there should be abundant aquatic plants. At that time, the weak water river will certainly not flow to Juyanhai, but will continue to flow forward, and will eventually flow along this canyon area, and finally merge into Heilongjiang in today's Hulunbeier Lake. In this way, Heilongjiang should be a river originating in Qinghai, called Weak Water and Heihe River, which is the longest river in China.
Of course, at present, I am not the only one who has such a guess, and others have it, but there is no evidence yet. At present, it seems that academic circles have not paid attention to this issue and have not conducted research. Once a man guessed the map of the world and put forward the hypothesis of continental drift, which was proved to be correct. This incident tells us that some reasonable guesses are not groundless.