What caused the drying up of the Sarasvatī River?

The drying up of the Sarasvatī River is believed to have been caused by a combination of natural factors. One major factor was the shift in the course of rivers, possibly due to tectonic movements and changes in the region’s climate. This could have led to a reduction in the river’s flow. Additionally, a decrease in rainfall in the region during the later stages of the Harappan Civilization might have further contributed to the drying up of the Sarasvatī River. As a result, many Harappan settlements located along the river were abandoned.

This question related to Chapter 6 Social Science Class 6th NCERT.
From the Chapter 6. The Beginnings of Indian Civilisation.
Give answer according to your understanding.