Who offended ancient Sichuan? Why is it easy for the population to decrease?

As a relatively closed geographical unit, Sichuan region (including Chongqing),with its unique Sichuan-Chongqing culture, has become China's unique humanculture today. Surprisingly, this rich and self-sufficient and prosperousland was not only affected by foreign forces for a long time in history, butalso suffered a sharp decline in population due to war. As a result, ithas absorbed a large number of immigrants from two lakes in history. Whyis Sichuan so unlucky?

01 Unique geographical conditions

From the geographical point of view, the entire Sichuan Basin is bordered bythe Hengduan Mountains to the west, the Yunnan-Guizhou Plateau across thesoutheast, across the Three Gorges along the mainstream of the Yangtze River,and eastward into the plain area of