Study On Flow State Change Of Wandering Section Of Lower Reaches Of The Yellow River When Xiaolangdi Project Put Into Operation

The river section from Tieshu, Mengjin, Henan Province to Gaocun, Shandong Provice, is a wandering section, with the length of 299 km. The section are wide and shallow, the flow state of the section is turbulent with a swing mainflow. So that the section is the key and difficult factor to regulate the lower Yellow River. In order to control the flood and to mitigate wangering of the section, since the beginning of building water control works on the Yellow River, some 3700 dams, battlements and revetments have beed set up. These works have played an impotant role in flood control.When Xiaolangdi Project completed and put into orperation, the inflow of water and sediment condition will be changed because of the regulation of the reservoir. Especially the initial 14 years, the reservoir will hold up sediment and release clear water, which may affect the river sections in Henan Province, especially the wandering sections. It will result in changes of flow state and endangering the water works, because the longitudinal addend by scouring and lateral slope failure. Thus, it is neccessary to analyze and predict the change of this wandering river section, so that to adopt the suitable counter-measures in advance.The dissertation focus on the main conflict of flow and sediment change, by analyzing the flow and sediment features, and change in rivercourse of typical period in histry, collecting the data of riverbed change. According to the flow and sediment change condition, combining the existed water works, and based on the results of former researches, the study are conducted on the law of flow state change by comparing rivercourse conditions before and after the completion of Sanmenxia Project, which may provide some idea for flow state change when Xiaolangdi Project completed and put into operation and some basic clue for the prediction of variation trend of river section from Tiexie to Shendi, from Shendi to Tieqiao near Zhengzhou, from Tieqiao nearZhengzhou to Dongbatou, from Dongbatou to Gaocun and so on in the year 2010 and the period 2010 to 2020. The result may provide some reference for flood control of these wangdering river sections, and some guidelines for planning of water projects and arrangement of project sequence.