Thirteen years after the Eastern Han Dynasty, the combined forces of Sun Quan and Liu Bei engaged Cao Cao in the Yangtze River, and in the end, Sun Liu's combined forces defeated Cao Cao with fire, known in history as the Battle of Chibi. The Battle of Chibi was a famous battle in Chinese history in which the less won more and the weak defeated the strong, and it laid the foundation for the establishment of the Three Kingdoms.
"Those who are close to him are condemned to the crime, and Liu Chun is bound. The Imabari water army of 800,000 people, Fang and the general will hunt in Wu."
Cao Cao's army was strong and strong, and he had newly reclaimed Jingzhou, and the momentum was in full swing, so why did he return home after a big defeat at Chibi? Historically, the benevolent see the benevolent, the wise see the wise, and the opinions are divergent, and this paper takes the special geographical environment and climate of Chibi as the foothold to analyze the factors that led to the defeat of the Cao Army.
Geography of the Chibi area
The terrain in the Chibi area is very narrow, swamps, gentle slopes, and dense river beaches, which have left hidden dangers for the Cao army to fight, and after the Cao army was defeated and retreated, it hastily retreated to the north bank of the Yangtze River, the north bank of the Yangtze River has been the swampland of Yun Mengze since ancient times, there are very few flat lands suitable for large-scale cavalry operations, the commanders of the Cao Army are not familiar with the geographical situation in Jiangnan, they have arranged all the infantry on the narrow strip of the Yangtze River line, the army is difficult to move, there is no place for use, and naturally they cannot assist the water army.
Sun Wu's army occupied favorable terrain from the beginning, its southern shore terrain was precipitous and difficult to land, easy to defend and difficult to attack, and its geographical location was condescending, which was convenient for observing the opposite shore; then the hilly area was lush with vegetation, and even if the infantry and horse of the Cao army hit the south bank, the difficulty of jungle warfare would increase. Cao Jun completely presented his disadvantages in front of his opponents.
The Art of War of Sun Bing:
"Three Miles of Depression Will Suffer Soldiers".
"Depressed", that is, swamp also. The climate in the Yunmengze area is humid, the river network is developed, the vegetation is dense, the organic matter decomposes quickly after the plant dies, and it is easy to form a swamp in the sinking zone and the meandering of the river, and the surface of the swamp is flat, but after entering, it will not stop sinking until it is completely trapped and unable to get out. In addition, the swamp is always surrounded by a variety of aquatic plants, especially reeds, which are dry and flammable in winter, which also provides conditions for fire attack.
Southeast winds
The essence of the Battle of Chibi was in the fire attack, but everything was ready, and it was necessary to use the east wind, but it was in the winter at that time, and the prevailing wind direction should be the northwest wind, how to fight the war when the southeast wind was blowing? Wind is an important factor in this battle, without which the fire attack could not be carried out smoothly. If it was an accidental wind, under the conditions at that time, how could Zhou Yu predict the weather conditions during the battle? The only possibility is that there is a localized prevailing southeast wind in the Chibi area.
How do southeasterly winds form in winter? It may be related to lake land wind and river land wind. There is also an important prerequisite for the formation of lake and land winds and river land winds, that is, the water body must be large enough, so as to form an independent air pressure system, and the water body of Yun Mengze at the end of the Han Dynasty was not as bad as that of later generations, and the conditions for wind formation were available. Due to the difference in the thermal properties of land and water, during the day the water forms a high pressure, it is blown from the surface of the water to the land, the friction on the water is small, the shelter is less, and the wind will be very strong, which we have experienced when we take the boat.
In addition, the Yangtze River area often has warm front activities, warm fronts from the south will also bring southerly wind, once it overlaps with the river land wind, lake land wind, the wind will increase, and the south bank terrain is higher than the north bank, the northwest wind will encounter tall mountains when going south, after encountering the cliffs on the south bank, it is partially offset, and the remaining part is bounced back to the north bank by the mountain wall, that is, the northerly wind is refracted into a southerly wind.
disease
Cao Jun came to the south to fight, the epidemic in the army, the soldiers' combat strength was greatly damaged, what kind of disease the Soldiers of the Cao Army had, there have always been different theories, there are several theories of schistosomiasis, malaria, typhoid fever.
Schistosomiasis and malaria are high incidence in the Jiangnan region, schistosomiasis lives in watery places, as long as there is a chance to contact the human skin will enter the body, therefore, soldiers as long as there is contact with water or water weeds on the shore may be infected, the incubation period of this disease is one to two months, Cao Jun entered Gangneung in September, the incubation period of this disease is one to two months, and by December it may be catching up with the onset.
Malaria, known as miasma and plague in ancient times, the transmission medium is mosquitoes, and the transmission season is from April to October, which has a certain relationship with the water period and rice growth period in the south, and people infected with this disease have a certain immunity, which also explains why the Sun Wu army, which has lived in the south for a long time, did not have disease during the war.
As for typhoid fever, it was a large-scale outbreak of epidemics at the end of the Eastern Han Dynasty, it is said that the population at that time was sharply reduced, seven out of ten died of typhoid fever, this disease occurs in winter and spring, mainly in the north, the soldiers of the Cao Army are mostly northerners, they may have been from the north to the south when some people have already got sick, to the south began to develop disease.
Due to the lack of information, we cannot determine the specific cause, but it can be inferred that the cause of Cao Jun's disease is complex, may suffer from a variety of diseases, and it is likely to be a local disease in the south, mainly parasitic diseases, and the poor resistance of northerners to this disease, coupled with the lack of water and soil, cold weather, aggravated the disease.
Of course, there are many other reasons for cao cao's defeat at the Battle of Chibi, geographical and climatic reasons, which are only one of them, and as for other reasons, due to space limitations, the author will not discuss them.