What geographic factor influenced the changing political borders in the Indus River Valley?

Climate change influenced the changing political borders in the Indus River valley.

Explanation:

The Indus River Valley today is located between Pakistan and North West of India. Around 1800 B.C.E., residents in the valley moved from the cities where the floodplain was located to the villages. Geologists believe that the reason for the move was climate change.

The lack of rains made farming difficult for the residents of the Indus Valley in the cities. When in the rural settlements the farmers depended on the rains to water their crops, instead of the flood which was more common in the cities.