Dating permian ru
The floor of this zone is sinking at a rate equal to that of deposition.
The Huang He—known in Chinese literature simply as the He (“River”)—turns eastward (immediately after its confluence with the Wei River) just west of the junction of the borders of Shaanxi, Shanxi, and Henan.
The Huang He is subject to extreme changes in summer and winter flow.
In time of maximum flow (summer) the river carries an enormous load of silt, gathered mainly in its course through the Loess Plateau of Shaanxi and Shanxi provinces.
The river was restored to its former northern course in 1947.
Under the People’s Republic, work along the river has included continued strengthening of the dikes and construction of the 30-mile- (50-km-) long People’s Victory Canal, which diverts Huang He water to the Wei River (of northeastern Henan).
The result was waterlogging of the soil, crop destruction, and famine.
The more fertile areas fringing the plains were the sites of early civilization.There is a Chinese saying that “if you fall into the Huang He, you never get clean again.” Prior to the damming of the river at Sanmen Gorge, the river was fast flowing through the gorge, and it was able to carry its load of silt until it issued onto the plain; at that point, its pace was checked, it could no longer carry the silt, and flooding occurred.Throughout historical times, this menace was met by building levees to contain the waters.The Huai River itself and all its major left-bank tributaries have their sources in the mountains of southwestern Henan.They flow eastward onto the Anhui Plain, subjecting it to disastrous floods.