The Indus Valley is one of the cradles of ancient civilization. Why is today with thar desert?

Although thar desert is located in the Indus Valley, due to the over-exploitation of the Indus River in history, vegetation destruction and soil erosion. In addition, the water vapor brought by the southwest monsoon in winter can't reach thar desert due to the blocking of mountains, and finally it can't form rainfall due to the control of subtropical high in summer.