What is Hetao Yellow River Diversion Irrigation?

Hetao area has a long history of irrigation from the Yellow River. According to the Records of Hanshu Valley, during the reign of Emperor Wu of the Han Dynasty, "Shuofang, Xihe, Hexi and Jiuquan all diverted their valleys to irrigate their fields". In this paper, Shuofang refers to the Hetao area in Inner Mongolia today, and Hexi refers to Ningxia and Hexi Corridor. Irrigation of farmland by the Yellow River indicates that irrigation of the Yellow River in Hetao area began in the Western Han Dynasty. However, large-scale irrigation from the Yellow River, whether it is Hetao irrigation area in Inner Mongolia or Hetao irrigation area in Ningxia, was in the Qing Dynasty.