Question

why was the harappan culture first called the indus valley civilisation

Answer 1

The Harappan Civilization has its earliest roots in cultures such as that of Mehrgarh, approximately 6000 BC. The two greatest cities, Mohenjo-daro and Harappa, emerged circa 2600 BC along theIndus River valley in Punjab and Sindh.

Answer 2

Well this civilization was built with river Indus as it's source of water hence the civilization was named as Indus valley civilization.The Indus Valley civilisation is also known as the Harappan civilisation because the first site of the archaeological remains of the Indus Valley civilisation was found at the modern site of Harappa, West Punjab, Pakistan.

Hope this helps :)