Gansu or Kansu (both: gänˈsōˈ) [key], province (2010 pop. 25,575,254), 141,000 sq mi (365,284 sq km), NW China. The capital is Lanzhou. Gansu is bordered by the Republic of Mongolia on the north. Its mountains include part of the Nanshan range and an extension of the Kunlun. The loess soil is fertile, but rainfall is inadequate and irrigation and land reclamation programs have had to be developed. Winter wheat, sorghum, millet, corn, rice, cotton, and tobacco are grown, especially in the Huang He (Yellow River) and Wei River valleys. Livestock (sheep, goats, horses, cows, and camels) are raised in the mountainous areas. Gansu's mineral resources include coal, copper, gold, nickel, zinc, and large deposits of iron ore and oil; two important oil fields are in the province. Lanzhou is a flourishing heavy industrial center, with one of the largest oil refineries in the country, and Yumen, though now declining, is China's oldest oil center; other towns are developing steadily. There is a satellite launch center near Jiuquan. Roads and railways have been extensively improved. Lanzhou is an important transportation hub; the Lanzhou–Xinjiang RR crosses the province, and the Lanzhou–Beijing RR has a connection through Mongolia to Russia.
Long isolated from the center of Chinese power, the Gansu area has traditionally been independent of all but the strongest central governments. After the 13th cent., Muslim strength grew, and fierce Muslim rebellions often plagued the central government. Today the province's strategic importance is enhanced by its control of communications into Xinjiang, Mongolia, and Russia. Although Han Chinese comprise most of the population, there are 11 major minorities, of which Muslims and Mongols are the largest. Gansu's boundaries have been changed several times in recent years. The former province of Ningxia was joined to it in 1954, then detached in 1958 and reconstituted as an autonomous region. In the 1969–70 redistricting, Gansu received a portion of W Inner Mongolian Autonomous Region. In 1979 this decision was reversed, and Gansu was restored to its former size.