Ngawa Tibetan and Qiang Autonomous Prefecture, also known as Aba, is an autonomous prefecture of northwestern Sichuan, bordering Gansu to the north and northeast and Qinghai to the northwest. Its seat is in Barkam, and it has an area of 83,201 km2 (32,124 sq mi). The population was 895,200 by 2022.

Barkam or Markang or Muerkvua is a county-level city in Ngawa Tibetan and Qiang Autonomous Prefecture, in the northwest of Sichuan province, China. The city seat is the town of Barkam. As of the 2010 Chinese Census, Barkam has a population of 58,437.