Causes of population mobility

Isn't this the content of human geography in senior two? Factors affecting population migration: 1. Natural environment factors, including climate, soil, fresh water and minerals; Second, social and economic factors, including economy, transportation and communication, family and marriage, education level, etc. ; Third, political factors, including war, national policies, political changes and so on. Generally speaking, it can be summarized as thrust (forcing people to migrate) and gravity (attracting people to migrate). In ancient China, the idea of immigration was very heavy, so the population migration was mainly based on thrust, mainly including wars, natural disasters and immigration. I won't give specific examples.