The Yellow River, orHuanghein Chinese, is the second longest river in China. It flows east for 5,464 kilometers, via provinces of Qinghai, Sichuan, Gansu, Ningxia, Inner Mongolia, Shaanxi, Shanxi, Henan and Shandong, until it empties into the Bohai Gulf, draining a basin of 752,000 square kilometers and boasting more than 30 branches. The thick deposits of unmodified Aeolian loess carried in the middle reaches accounts for over 90% of the sediment in the main channel downstream.
The Yellow River Basin is the cradle of Chinese nationality. As early as one million years ago, the Lantian Man had been living in the Yellow River Basin, and Dali Man Dingcun Man and Hetao Man ancestors one generation after another had been living and working along the Yellow River, and created magnificent ancient civilization. The remains of ancient culture like Yangshao Culture, Majiayao Culture, Dawenkou Culture and Longshan Culture can be found everywhere in the whole river basin from the upper reaches to the lower reaches. Over 1,000 sites of Yangshao Culture have been discovered with large quantities of stoneware, bone ware and painted pottery, etc. Yin Ruins unearthed here is the best proof that Chinese oldest nation was first established in the middle and lower reaches of the Yellow River.
Historical records indicate that the river's levees were breached more than 1,500 times and its course changed 26 times in the last 2,000 years. During such breaches, the floodwater would rush onto the surrounding lands, not only inundating farmland and communities, but also taking over existing river channels. An average of 1.6 billion tons of sediment enters the river channel annually, of which about 1.2 billion tons is carried out to sea, leaving behind a substantial amount (about 400 million) to contribute to the silting of the river channel. Throughout history much of the river management effort had been devoted to improving the flood prevention capability of the levee-lined channel.