Why do so many people migrate in Hongtong County?

At the end of Yuan Dynasty and the beginning of Ming Dynasty, there were frequent wars and natural and man-made disasters in the Central Plains, and the population of Henan, Hebei and Shandong decreased sharply. At that time, Shanxi was relatively stable and densely populated, so several large-scale population migrations were launched in the early Ming Dynasty. This is caused by political reasons. Many of them moved from Hongdong County, Shanxi Province, so everyone still has a historical origin.