Causes of ancient locust migration

When there was famine and chaos in the Central Plains at the end of the Yuan Dynasty, compared with neighboring provinces, Shanxi remained socially stable, economically prosperous and populous. Coupled with the influx of refugees from neighboring provinces into Shanxi, the southern part of Shanxi is densely populated. The principle of the Ming government's immigration was to move farmers from narrow townships to wide townships, and from places with more people and less land to places with less people and more land. Therefore, Shanxi has become the main birthplace of immigrants. Immigrants in the early Ming Dynasty recorded in China historical documents have a history of about 50 years, from the early years of Hongwu to the fifteenth year of Yongle. Most of the people who were moved were in southern Shanxi and southeastern Shanxi, and there were only a few counties in Jinzhong. At the beginning of Ming Dynasty, Shanxi was divided into five states, three zhili states, sixteen scattered states and seventy-nine counties, and Pingyang State was the place with the largest population.