What is the future development of China?

The Yellow River civilization is no exception. By the Zhou Dynasty, the forest coverage rate of the Loess Plateau reached 53%, but with the increase of population, the demand for cultivated land became increasingly urgent, and forests were cut down in large quantities. In 2 15 BC, Meng Tian, a general of the Han Dynasty, defeated the Xiongnu and recovered the Hetao area, where a large number of immigrants came. The Han people soon turned the occupied Xiongnu pasture into farmland. Emperor Wu of the Han Dynasty first recovered the Hetao area, and then recovered the Hexi Corridor. The whole Yellow River basin is under development. During this period, the area of cultivated land increased greatly, and it may have reached more than 500 million mu around the year A.D.. The population also increased rapidly, reaching nearly 60 million at the beginning of AD, which was the first population peak in the history of China. The vigorous development of the Yellow River basin in Han Dynasty caused the population crisis in the middle and lower reaches of the Yellow River, and the destruction of vegetation in the middle and upper reaches made the Yellow River begin to endanger people's livelihood. Since then, dynasties have changed, wars have been fought for years, and the population has decreased sharply, but to some extent, it has eased the environmental pressure and concealed and diluted the ecological problems. When the Jin Dynasty unified the whole country, the historical population was only160,000. A large number of farmland is barren, and some have become pastures. On the contrary, it gives the ecosystem of the Yellow River basin a chance to recuperate. During this period, perhaps due to the return of nomadic people in the north, the flood of the Yellow River was alleviated. The Qingming politics in the early Tang Dynasty made the population lacking because of the war rise sharply. By the time of Tianbao (the middle of the 8th century), the national population had risen to nearly 60 million. The increase of population is accompanied by large-scale land reclamation, and the land reclamation in the Yellow River Basin has reached its peak. In order to resist the intrusion of nomadic people in the northwest, the Tang Dynasty implemented the policy of reclaiming farmland and clearing the border in the northwest border, and cultivated a large area of cultivated land, and the society suddenly became well-fed and prosperous. However, the development of the Yellow River Basin has reached its ecological limit. Vegetation in the upper reaches of the Yellow River has been seriously damaged and soil erosion is extremely serious. During the Tang Dynasty, the Yellow River was extremely turbid. After the An Shi Rebellion, this ecological boundary began to appear. The destruction of war is a factor, but it is only an opportunity to expose the existing ecological boundary. During this period, the population of the Yellow River basin dropped sharply, and productivity could never be restored. The sediment concentration of the Yellow River reached 50% in the Song Dynasty, and then it went from bad to worse, reaching 60% in the Ming Dynasty and 70% in the Qing Dynasty. A large amount of sediment makes the riverbed of the Yellow River rise day by day, and some reaches even rise above the ground, becoming suspended rivers. The flood of the Yellow River has become a big headache in the past dynasties, and the Yellow River has really become a harmful river. It was also during this period that a large number of northerners moved south, flocked to the Yangtze River basin and developed towards the lower reaches of the Yangtze River, especially the Yangtze River Delta. The Anshi Rebellion can be regarded as a symbol of the transfer of Chinese civilization from the Yellow River basin to the Yangtze River basin. From the mid-Tang Dynasty to the Northern Song Dynasty, the development of the Yangtze River basin was still to destroy forest vegetation and build dams around lakes to reclaim paddy fields. The latter is the most. The direct consequence of reclaiming land from lakes is to cause floods. There are many lakes, large and small, in the Yangtze River basin, which, like artificial reservoirs, constitute a natural regulator of runoff in the Yangtze River system. A large number of lakes are surrounded by fields, which makes the natural regulator fail, and the Yangtze River basin is caught in the flood and drought disaster of "rain is easy to flow, sunny is easy to dry". In the rainy season, the flood has nowhere to be placed, and the dam is in danger. In the rainy season, there is no reserved water to irrigate. After the demise of the Northern Song Dynasty, a large number of people from the north moved south again, which led to overcrowding in the southeast and extremely tense relationship between people and land. The mountains, lakes and cultivated land in this area have been over-cultivated. The early Ming Dynasty was also to restore the population, emigrate to the north and reclaim wasteland. However, the population of the Ming Dynasty grew too fast and soon exceeded 60 million. The speed of land reclamation can't keep up with the speed of population growth. 1400 The population is about 65-80 million, and the cultivated land area is 370 million mu. /kloc-in 0/600, the population reaches 200 million, and the cultivated land is 670 million mu. A large population and a small population may be an important reason for the social unrest in the Ming Dynasty. The Ming and Qing wars greatly reduced the population, but it quickly recovered in the Qing dynasty, and the population of the Qing dynasty soared because the population base of the Ming dynasty was already very large. In the early Qing Dynasty, in order to encourage reclamation and prevent unrest, the population growth tax was abolished (fifty-one year of Kangxi 17 12), which greatly increased the population of the Qing Dynasty. 1766 (in the 31st year of Qianlong), the official population exceeded 200 million, and in the 13th year of Daoguang (1833), the official population was nearly 400 million. In order to feed such a large population, apart from increasing the grain output per unit area, we still have to rely on reclamation. The plains were over-cultivated, and people flocked to the mountains. Fujian, Jiangsu and Zhejiang immigrated to Jiangxi and Hubei, and Jiangxi and Hubei immigrated to Guizhou and Sichuan, that is, the population in the middle and lower reaches of the Yangtze River moved upstream. New immigrants destroy forests and cultivated land in an extremely backward way, and destroy mountain forest vegetation on a large scale, which leads to soil erosion in the upper reaches of the Yangtze River, and then affects the ecological environment in the middle and lower reaches. Because the mountains in the upper reaches cause soil erosion and the lakes in the middle and lower reaches cause floods, the middle and lower reaches of the Yangtze River have been flooded for years. The only policy protection in Qing Dynasty was Northeast China and Mongolia. Northeast China is the hometown of Manchu. In order to protect this homeland, the Qing dynasty banned Han people from entering the customs to reclaim land. Because of Mongolia's ethnic segregation policy, Han people are forbidden to enter Mongolia to cultivate land. Although these policies are not strictly implemented, they objectively protect the ecosystems of these two places. The virgin forest in Northeast China has been preserved, and it is still the largest forest-intensive area in China. Throughout thousands of years of feudal social history in China, progress is always accompanied by ecological destruction. Years passed, and the prosperity of many dynasties was washed away. Jiangshan is still silent, but the ecological environment is deteriorating. Ironically, however, China culture is famous for its green concept of "harmony between man and nature". "Harmony between man and nature" emphasizes the harmony, adaptation and harmony between man and environment. Here, the environment is not only a geographical environment, but also a social environment and a humanistic environment, which is a generalized "circle" and "field". The so-called local conditions, the so-called "right time and right place" and the so-called "right time and right place" are all manifestations of this idea. "Yi Chuan Classical Chinese" said: "Husband is in harmony with heaven and earth, with the sun and the moon, with the four orders, with ghosts and gods, with good and bad luck, with nature, and with the day after tomorrow.