What are the reasons why the ancestors of the Jews moved around in order to find a suitable place to live?

In ancient times before 3000 BC, the land in Canaan was moist and fertile, with lush forests and grasslands everywhere, and agricultural production activities had appeared. However, as the weather becomes drier and drier, large areas of forests and grasslands gradually disappear, and the surrounding desert of sinai and Arabian deserts quickly encroach on countless fertile fields in Canaan, the lack of water resources has become the most puzzling problem here. Therefore, in Hebrew civilization, on the one hand, irrigation technology plays an important role in agricultural economy, on the other hand, rainfall largely determines the abundance of agricultural harvest, and Jewish ancestors often have to move around to find a more suitable place to live because of drought.

Negev desert landform