How can I not look at the geography, the climate?
The following content can be eaten in conjunction with the recent chapters.
Talking about the terrain of Jianghan first, it is inseparable from Yunmengze.
First, Yun Mengze According to the later generation of Hubei Geological Examination, it includes but not limited to reading historical materials, field surveys, punching drilling and other detailed studies to obtain the following conclusions.
10,000 years ago, Yun Mengze did not exist !!!
When 10,000 years ago, the earth warmed, rainwater increased, and Yunmengze gradually formed.
5,000 to 7,000 years ago, Yun Mengze's area was about 8,400 square kilometers.
More than 3,000 years ago, Yun Mengze reached more than 12,000 square kilometers. This is the heyday. Generally, it is also a period of victory when history books began to talk about Yun Mengze.
With the expansion of the lake, the rivers flow slowly, and the sediment began to deposit.
At first, it was just underwater triangle, and the water gradually exposed to form land. From this time, Yun Mengze changed from prosperity to decline.
During the Warring States Period, the scope of Yun Mengze roughly arrived in the west to Jiangling; arrived in the Yangtze River in the south; in the east to Wuhan; north to Hanshui Basin.
How to describe this place? It is roughly equivalent to Hubei Jianli, Honghu, Qianjiang, Most of Xiantao, and Jiangling, Shitou.
So, why is Tan Tu still painted Xiaogan, Anlu, and Yunmeng area is also the swamp area? In fact, it is different.
This is also the water in the water, but it is not part of Yun Mengze. It is controversial.
In addition, some people say that this is actually Yun Mengze's "Manzhu", that is, the year when there are many rainfall. Yun Mengze will spread outwards. In the arid year, the drone area will be discontinuous from Yun Mengze's body.
During the two Han Dynasty, the Delta, the land of the land gradually became large, and the main body of the lake area was gradually pushed away from Hanshui, pressed to the south of the Qianjiang River, north of the Yangtze River, and what was the vicinity near the Qianjiang River?
Yes, it has become a swamp from the lake.
This place is in the book at this time.
During the Northern Wei Dynasty, Yunmengze became a state of coexistence of lakes+swamps+trigmented. Lands were increasing. Lakes were divided into large quantities. What major lakes appeared in the lake that were lazy.
Dahu was very large in Weipu, and the Tang Dynasty was very small, and the Song Dynasty disappeared.
During the Tang Dynasty and years of the Horses Lake, the summer and autumn rose water.
Fifteen miles of Zhou Hui, "telescopic" are very large, the concepts of Feng Shui and the dry period are just like the "grassland" of Poyang Lake during the arid years.
But don't look at the area of ​​the Horsberry Lake in the Tang Dynasty that it has shrunk greatly than that of the Wei and Jin dynasties. This kind of land also needs to be developed manually. At least it needs to be built, otherwise it is a lake plus a roaming area.
On the whole, it is such a common role of natural changes and artificial development. The process of Yun Mengze gradually disintegrated.
To sum up, in 5000 BC, Yunmengze area (unit: square kilometer): 8442.5
This number is calculated from modern exploration and drilling. It is difficult for me to be precise to 0.5, but it will generally float around this number.
In 2000 BC, the area of ​​Yunmengze was 12250.
In 1927, Yunmengze area: 5450.
In 1975, Yunmengze area: 3157.4.
I don't know how much it is now.
The above data is only the actual area of ​​Yunmengze. In fact, there is a diffuse area outside it, which is mostly swamp. The swamp areas in Anlu, Yunmeng and Xiaogan in Hubei Province are not included in this data.
Second, the river course of the Yangtze River used to be further north than it does now.
The Yangshui River, Xiashui River, etc. that appear in the book are all bifurcation channels of the ancient Yangtze River. At that time, they flowed eastward from near Qianjiang River and were not clearly separated from the Han River.
Among these Han currents, Yangshui was the first to be abandoned.
In the late Spring and Autumn Period, the State of Chu used the old Yangtze River route in Yangshui to build a canal.
The gushing water was gradually abandoned during this era in the book. By the Northern Wei Dynasty, the upper reaches of the gushing water had stopped flowing.
The reason is unknown.
Xia Shui still bears the important responsibility of diverting the Yangtze River.
So, where does the water in these rivers come from? The water divide.
During the Northern Wei Dynasty, there were more than 20 water diversions on both sides of the Jingjiang River. "Before the Song Dynasty, all the points were unblocked, so the river had few troubles." In fact, it was not unblocked, but the existence of Yunmengze, which allowed it to be used as a flood discharge area to ensure
Gangneung and other big cities are safe.
During this period, among the many rivers in the north of the Yangtze River, none could be separated from Yunmengze.
Until the middle and late Tang Dynasty and the Song Dynasty, as the land area formed by delta sedimentation continued to increase and the degree of human development deepened, the Han River and the Yangtze River returned to their respective troughs and entered a period of single straight river channels.
Third, humans have entered the Yunmengze Delta since it silted up and became land.
How do they survive? The answer is to plant polders.
That is to build dikes to prevent the swamps and lakes from overflowing, and to develop farmland.
This has formed a characteristic, that is, human beings mostly gather in places with a lot of siltation to form landmasses. As mentioned in the previous chapter, the population cannot be evenly distributed, but gathers in points, forming an area with a relatively large population.
, and in the middle of the area, there are either water swamps or forest reed swamps, that is, the ancients described Taibai Lake after the disintegration of Yunmengze as "a vast expanse of reeds" and "a hundred miles of wilderness".
In northern Jingzhou, Wancheng and Xiangyang are the central gathering points.
South of Xiangyang and north of the Yangtze River, Jiangling and Anlu are the core.
To the south of the Yangtze River, the triangle area of ​​Wuchang, Xiakou, Xiangnan (now west of Xiangtan), (Iing, near today's Hengyang), and Changsha is the main area. In addition, there is also a large population near Lingling City.
Overall, it is a bit like relying on the development model of colonial strongholds. There are more people near colonial cities, and the environment becomes worse as you go outwards, the lower the degree of development, and the more barbarians there are.
In these areas, during the Wei and Jin Dynasties, it was normal to go a hundred miles without seeing anyone. People were still too busy developing regional central cities, let alone the areas with frequent floods and swamps. They really didn't have the energy.
The population census during the Taikang period of the Western Jin Dynasty. Although the number of hidden households is very amazing, it can be seen by a trend.
At that time, the two states of Jingxiang had not been divided.
Changsha County: 33,000 households;
Lingling County: 25,100 households;
Nanyang County: 24,400 households;
Jiangxia County: 24,000 households;
Hengyang County: 23,000 households;
Xiangyang County: 227,000 households;
Shunyang County: 20,100 households;
Xiangdong County: 195,500 households;
Yiyang County: 19,000 households;
Wuchang County: 14,800 households;
Wuling County: 14,000 households;
Jianping County: 13,200 households;
Shaoling County: 12,000 households;
Guiyang County: 113,000 households;
I won't write below 10,000 households.
Note: At that time, some counties had not yet been split. For example, Yiyang County was included at the time, including the second of Shinye County, and the merger was calculated.
In simple terms, in this era, Jingzhou can be divided into three parts: northern, middle, and south.
Among them, Nanyang, Shunyang, Yiyang (including Xinye, Sui) and Xiangyang have a total of 86,200 households.
From here to the south, you are facing Yunmengze and various drilling areas.
I call this one in the middle, mainly Jiangxia, Turns, and three counties in the south, a total of 79,000 households; half of the Jiangling on the edge of Yunmengze Joshi occupied the big head.
To the south is the south of the Yangtze River or the main body in the south of the Yangtze River, with a total of 187,700 households.
That is, 86,200 households in the northern part of Jingzhou (Jingxiang Division), mainly in the South Yang Basin and Xiangyang, accounting for 24.4
%;
79,000 households in the middle (Jianghan Plain), accounting for 22.4%
187,700 households south of the Yangtze River, accounting for 53.2%;
The least population is the Jianghan Plain, and the degree of development is even lower than Jiangnan.
The ground around Xiangyang is really good, but in terms of supply transportation, it is more convenient to contact Nanyang, and it is inconvenient to Jiangling. Jiangling.
For the southern regime, this is a protruding part that Yun Mengze blocked in the north, and it is lonely.
In history, Tao Kan didn't want to keep Xiangyang. He didn't even want to keep the Jiangbei land except Jiangling.
The reason lies in this.
The Jianghan Plain looks a lot. In fact, Jiangling, which is on the edge area, has a large population in Anlu, and the people in the swamp area are scarce.
In a military perspective, this is the natural barrier of the southern regime.
In fact, I have been difficult to understand a long time ago. Why did Dongwu dare to move the capital Wuchang without Xiangyang and still retain a large area of ​​land in Jiangbei? How can I keep it?
Relying on Yunmengze, dense water network, relying on the muddy of the swamp, and relying on the unmanned district.
There is a place developed from the north bank of the Yangtze River. As a production base, it supports the army to cross the north of Yunmengze area, and even touch the butt of Xiangyang.
At that time, Cao Cao went south and reached the Chibi of the core area of ​​Yunze. A big defeat, half of the dead (about 40,000 to 50,000, mainly the Jingzhou Army). In principle, he had more than 200,000 troops. As for this, do this?
What's more?
The reason was that he could not get much supply around Chibi. He rely on the scarce areas of people in the scarce area behind the back. In addition, although the winter, it was really uncomfortable.
The winter caused by hunting is that the bacterial virus is not active enough, and the chance of getting the disease is reduced, which does not mean that there is no disease.
Cao Cao was unwilling to keep Jiangling and gave up.
Jiangling is outside the edge of Yunmengze, and the environment is not so bad. There are many land between Xiangyang.
Cao Cao chased Liu Bei even can send cavalry, but he was still reluctant to keep, because this place was against the Yangtze River, and the environment may not be very suitable.
It is Dangyang Road from Xiangyang to Jiangling south.
From Nanjun, Jiangling to the east, along the middle of Yunmengze, a road that accumulated into a land, reached Ulin, called Huarong Road.
Write so much first.
When marching and fighting, you must understand the geography. If you have the opportunity to cross, remember this one, remember this,
Don't look at the map to march randomly.
Chapter completed!