Yinchuan is the capital of the Ningxia Hui Autonomous Region, People's Republic of China, and former capital of the Western Xia Empire of the Tanguts. It has an area of 4,467 sq. km and a total population of 1.99 million. Its built up area is home to 1,513,151 inhabitants spread on 3 urban districts. The name of the city literally means "silver river;" the character for "river" is the same as that in Sichuan, but not as those in, for example, the Yellow River or Yangtze River. Yinchuan, however, remains largely nonindustrial. The immediate plains area, intensively irrigated by a system developed as long ago as the Han (206 BC-AD 220) and Tang (618-907) dynasties, is extremely productive.