1. Many explanations have been given for the end of the Harappan civilisation. These range from climate change, deforestation, excessive floods, the shifting and drying up of rivers due to over use of the landscape. 

2. The rainfall in the Indus region slightly increased around 3000 BCE and further decreased in the earlier part of the 2nd millennium BCE. 

3. It may have adversely affected agriculture and stock breeding. The decline of the decreasing fertility on account of increasing salinity of the soil caused by expansion of the neighbouring desert. 

4. Others attribute it to sudden subsidence or uplift of the land which caused floods. 

5. Wheeler believed that the civilisation was destroyed by Aryan invaders. His views were based on the skeleton remains recovered from Deadman lane and correlated to the archaeological evidence of the Rig Veda. 

6. George Dales refutes Wheeler, he explained that the skeletons found in the site, did not belong to the same period. The citadel, the only fortified part of the city yielded no evidence of final defence.

7. The end of the Harappan civilisation was a gradual process. By 1800 BCE most of the mature Harappan sites in the region such as Cholistan had been abandoned. There was an expansion of population in new settlements in Gujarat, Haryana and western Uttar Pradesh. 

8. The important features associated with Harappan civilisation on writing, weights, pottery, artefacts, long distance trade, craft, disappeared. Even the house construction techniques deteriorated. The urban way of life gave way to a rural way of life. It appears that a strong unifying element perhaps. The Harappan state came to an end.