Question

Area drained by a river and its tributaries is called

Answer 1

it is called a river basin
eg;Ganga and its tributaries together form Ganga river basin

Answer 2

The area which is drained by a river along with tributaries is collectively known as “river basin or drainage basin”.

Explanation:  

“The drainage system of India” is divided into the following two groups:

1. The Himalayan rivers and,
2. The Peninsular rivers.

The Himalayan rivers consists of three main rivers with its tributaries, i.e., the Indus, “the Ganga and the Brahmaputra”. They are perennial and snowfed. While, the Peninsular part concludes Narmada, Tapi, Mahanadi, Krishna, and Kaveri. They are short but have had use for irrigation after constructing dams over these rivers. They are rainfed rivers.