Chapter 15 Section 5 Geographical Thoughts in Pan Jixun's Theory of Huang Zhi

Pan Jixun (1521-1595 A.D.), the Minister of River Supervision in the Ming Dynasty of my country, and a famous hydraulic scientist, was ordered to supervise the river four times. It lasted 27 years and made outstanding achievements. He occupied an important position in the history of Yellow River management in my country.In his theoretical strategy of governing the Yellow River channel, there are important geographical thoughts. The Yellow River flows through the Loess Plateau region, and the river's sediment concentration is extremely high, causing frequent flooding, migration, and diversions in the downstream, which directly threatens the lives and property of people in the middle and lower reaches of the Yellow River, and even the political and economic safety of the country.Therefore, the governments of all dynasties in our country have treated the management of the Yellow River, especially the prevention and control of downstream river migration and diversion, as a top priority, and many famous river management experts have emerged.Among them, Pan Jixun's theory and practice of river control are particularly famous, and have always influenced the river control strategies of Chen Huang and Jin Pu in the Qing Dynasty.This is the theory of Yellow River Control founded by Pan Jixun, "build embankments to draw water, and use water to attack sand".

It is not difficult to see that Pan Jixun's theory is based on the basic geographical principle of the relationship between river transport force, flow, and velocity.That is: to correctly understand the basic principle of geography (hydraulic law) that the greater the velocity and flow of the river, the stronger the ability to transport sediment (alluvial). In fact, this geographical theory was correctly pointed out by Rong Zhang when he talked about the silt of the Yellow River in Wang Mang's time in the early 1st century AD ("Hanshu · Gouge Zhi").It is a pity that subsequent generations of Yellow River governance did not pay much attention to the application of this geographical theory, and often adopted the method of diverting the flow to suppress the water potential, which violated the characteristics of the river.It was not until Pan Jixun's time that he realized the importance of this theory for river governance again.In "Overview of River Defense: Distinguishing Confusion over Rivers", he analyzed:

The water will slow down, the sand will stop when the speed slows down, and the river will be full when the sand stops.If the hydration is strong, the momentum will be fierce, if the momentum is strong, the sand will brush, and if the sand brushes, the river will be deep. Therefore, he believes: Build an embankment to contain the water, and use the water to attack the sand. If the water does not overflow on both sides, it will go straight to the bottom of the river. There is a certain principle, an inevitable trend, and the reason why this combination is stronger than separation. Here, his embankment is no longer a passive defense, but an active guidance.In order to "bundle water" more effectively, he also formulated specific measures such as corresponding embankment rules and requirements according to different terrains and terrains.As a result, the implementation of this strategy for controlling the Yellow River based on scientific theory not only deepened the river course, but also changed the situation of high sand accumulation in Haikou, opened up a way for the Yellow River to flow into the sea, and made great achievements in controlling the Yellow River. effectiveness.

The establishment of Pan Jixun's theory of controlling the Yellow River not only shows that the Chinese people have a correct understanding of the geographical theory of alluvial and erosion, but also fully demonstrates that our country has correctly applied this geographical theory to production practice very early.