Explain why nomadic tribes need to move from one place to another. What are the advantages to the environment of this continuous movement?

The nomadic tribes need to move from one place to another in search of new pastures. When the grass in a particular part is exhausted and the season becomes unconducive, the nomadic tribes move to some other area. The seasonal movement of nomadic tribes is beneficial for the environment. It allows natural re-growth of grass in the pastureland

Nomads are people who do not live in one place but move from one area to another to earn their living. Their main occupation is cattle rearing for which they need availability of water and pastures for grazing their animals. When the pastures get depleted they move to another place with their animals, looking for pasture and water. When the water and pasture get depleted they move again and keep repeating the cycle.

Advantages: 

(i) The movement of the nomads allows the pasture to regrow and recover. 

(ii) It helps to protect the ecology of the environment. 

(iii) It prevents the overuse of pastures. 

(iv) The cattle by the dung help in providing manure.