Why did part of the Tengger Desert region return to Inner Mongolia in 1979?

The transfer of territory in 1979 was not based on a specific functional reason for the desert region itself, but rather the result of a broader administrative reversal by the Beijing government.

In 1969, the government had significantly reduced the size of the Inner Mongolia Autonomous Region, transferring large portions of its territory to neighboring provinces and regions, including the Hui Autonomous Region of Ningxia. This 1969 reorganization, which involved the transfer of about two-thirds of Inner Mongolia's former area, was officially terminated in 1979. Consequently, the territory that had been detached and incorporated into regions like Ningxia was restored to Inner Mongolia as part of this policy reversal.12