Reason Behind Collapse of the Indus Valley Civilization (IVC)

A study published in the journal Communications Earth & Environment highlighted that the downfall of the Harappan civilization was not due to a single catastrophic event.
The research shows that previous beliefs suggested a singular cause, but the decline was instead driven by multiple long-term environmental and societal factors.

Key Findings of the Study

Impact of Droughts: Contrary to popular belief, the civilization did not collapse due to one catastrophic reason.
The study indicates that a series of prolonged droughts, each lasting decades, were a significant factor in the decline.
Four major drought events, each spanning over 85 years, occurred between 2425 and 1400 BCE, impacting nearly the entirety of the region.
Dwindling Resources: Hydrological changes led to the desiccation (drying up) of rivers, lakes, and soils.
o These changes likely prompted the Harappans to frequently relocate in search of more viable living conditions.
Declining Trade: Low water levels hindered trade activities that relied on river navigation.
o Reduced water availability also made agriculture more challenging and forced populations to migrate.
Other Factors: The decline was compounded by diminished food supply.
Fragile governance structures further weakened the resilience of Harappan cities.

Other Major Theories of IVC Decline

Catastrophic Flooding (Raikes’s Hypothesis): Evidence shows that houses in Mohenjodaro were covered with silty clay.
o Rebuilding activities in these areas support the flooding theory.
Earthquakes: Earthquakes may have raised flood plain levels, blocking rivers from reaching the sea.
o This blockage forced water into cities, contributing to destruction.
Changes in the Course of Rivers: The Indus River reportedly shifted about thirty miles away from Mohenjodaro.
Drying up of the River Ghaggar-Hakra in Rajasthan: This environmental change likely reduced water availability for settlements.
Barbarian Invasions: Ancient texts like the Rig Veda mention a place called Hariyupiya, probably referring to Harappa.
o These texts indicate that Aryans fought a battle in this region, suggesting external conflicts.
Ecological Imbalance (Gradual Decline): Historian Fairservice emphasized that the delicate ecological balance of semi-arid areas was disturbed.
o Population pressures and rapidly depleting resources contributed to long-term decline.
Climate Change (D.P. Agarwal): Gradual climatic shifts, including reduced rainfall and changing river patterns, also played a key role in the civilization’s collapse.