series of alluvial plains of uneven width along the Yangtze River (Chang Jiang) and its major tributaries, beginning east of Yichang (Hubei (Hupeh) province), east-central China. The middle Yangtze Plain covers parts of northeastern Hunan, southeastern Hubei, and north-central Jiangxi (Kiangsi) provinces and contains several lakes, including Dongting Lake, Lake Poyang (Poyang, Lake), and Lake Hong. The lower Yangtze Plain includes the Yangtze River delta, Lake Tai (Tai, Lake), and the area along the Yangtze in south-central Anhui province. There are a few isolated hills, but most of the plains are level and lower than 150 feet (45 metres) above sea level. The slopes of the valleys bordering the plains have been converted into a system of flat terraces, one above the other. The rivers, canals, and lakes form a network of navigable waterways. Flood diversion projects built after 1949 have helped control flooding. Rice, cotton, wheat, rapeseed, mulberries, bamboo, hemp, and fish are raised. The major cities are Shanghai, Nanjing (Nanking), Hangzhou, and Wuhan.