What are the probable causes of the downfall of the Harappan civilization?



The Harappan people established contacts with the outside world by sea, and not by the overland route. It has been pointed out Sheeren Ratnagar that articles used to move between Harappa and Iran, Bahrain, Oman-peninsula and Sumer.

In Oman evidence of Indus imports such as vases, metal arte facts, ivory work have been found. The ships sailing from Indus ports entered Persian Gulf through Oman and proceeded up to Bahrain and Faylakah. These two places were known to the Sumerians as 'Dilmun'. Dilmun was the gateway of Mesopotamia (present Iraq). The Mesopotamian people called the Indus basin by the name Meluhha.

Thus it may be said that the Harappan people had close trade relations with different centers of Sumer and Mesopotamian civilizations. Historians have suggested various causes for the decline of the Harappan civilization. One explanation is that the civilization disappeared due to the decreasing fertility on account of salivation of the soil.

Some are also of the opinion that the people were forced to migrate elsewhere when the city of Mohenjodaro had declined due to the pressure of population. Changes in the course of the river Indus have also been suggested as a possible cause of the decline. Some evidences, however, indicate that the devastating floods seriously disturbed the progress of the civilization.

In fact, excavations reveal that Mohenjodaro itself was devastated by flood I more than once. Thus it may be reasonably argued that deep flooding resulted in the economic decline of some of the Harappan settlements. But the most popular explanation has been that the Harappan culture was destroyed by the invasion of the Aryans. Recent researches, however, have exonerated the Aryans, rejecting the theory of a 'violent end' of the Harappan civilization.

The new point of view lays emphasis on the arguments that the fall of the civilization could have been strongly influenced by the changes in climate.