Possible reasons for the decline and fall of the Indus civilization?

Question

Discuss some of the possible reasons for the decline and fall of the Indus civilization. include any environmental reasons

Answer 1

http://en.wikipedia.org/wiki/Indus_Valle...

Answer 2

Climate change is the most accepted reason.  The area became drier and hotter, water sources began to disappear, the soil became more sandy and as a result regular flood patterns turned to flash flood events carrying away what soil nutrients were left.  It becomes a viscous cycle.  Similarities can be seen in Maya civilization.  Changes in weather patterns caused flooding and erosion until complex society (read city) was no longer sustainable.  At this point the birth rate plummets, population declines and disperses as disease becomes harder to resist in dense population due to poor nutrition.  Warfare is another likely result though the evidence of this is more difficult to see as it is likely small roving gangs. But the main cause is climate/weather changes.