Why did the population decrease in the last years of Kangxi?

There are many reasons for the population decline in the last years of Kangxi:

1. War and famine: During the reign of Kangxi, China experienced many wars and famines, such as the Jinchuan earthquake, the Kangxi flood, and the San Francisco Rebellion, which resulted in a large number of deaths and displacements.

2. Immigrant evacuation: During the Kangxi period, a series of policies were implemented to move the border ethnic minorities to the mainland, which led to the immigration of many ethnic minorities to the mainland and the loss of some Han Chinese.

3. Conscription system for military service: During the reign of Kangxi, a large number of people were recruited and sent to the battlefield for military operations, resulting in a large number of deaths and losses.

4. Diseases and infectious diseases: During the Kangxi period, many diseases and infectious diseases were spread due to the lack of medical conditions and sanitation. For example, measles, smallpox, tuberculosis and other diseases have caused a large number of deaths and infirmities.