What changes have taken place in Jiangnan area of China from the Western Han Dynasty to the Southern Dynasties?

Population growth, economic development and civilization progress.

Reason:

1, after the Western Han Dynasty, wars broke out in the northern and central plains, including the overthrow of Wang Mang, the Yellow turban insurrectionary, the scuffle at the end of the Han Dynasty, the dispute between the Three Kingdoms, the Eight Kings Rebellion and the Five Rebellions in China. People were displaced and suffered greatly. Coupled with frequent natural and man-made disasters, people have to move south in order to avoid this seemingly endless disaster, which makes the population in the southern region increase rapidly.

2. During the China Chaos, the northern regime practiced a system of discrimination and slaughter of Han people, which caused a large number of Han people in the north and the Central Plains to move southward.

3. A large number of Han people from the north and the Central Plains moved to the south, which brought advanced farming and textile technology to the people in the south of the Yangtze River, which made the agriculture and commerce in the south of the Yangtze River develop rapidly and provided a material basis for the rapid economic development in the south of the Yangtze River.

4. The regime of Jin Dynasty and Han Dynasty moved south, and the political center of Han nationality moved south. The government implemented a series of policies to develop production, in order to compete with the north for accumulated strength, and created favorable political conditions for the economic development of the south of the Yangtze River.

Since the end of Han Dynasty, a large number of northern gentry moved south, bringing advanced culture to the south of the Yangtze River.

6. Since the Wu State in the late Han Dynasty, the northern region, the Central Plains, Wu Chu and Bashu regions in the south have suffered from repeated wars, and only Jiangnan region is relatively stable, which also provides a favorable external environment for the economic development of Jiangnan.