Unsteady Flow Impact on Downstream Waterways and Control Measures Research of Pingban Hub in Nanpanjiangjiang River of Guizhou

After the completion of the hub on river, its scheduling unsteady flow generated an adverse impact on the downstream navigation. In this paper, according to the unsteady flow data of PingBan hub in Nanpanjiangjiang River in Guizhou province, researched unsteady flow spread characteristics and rule in hub downstream channel. Studies have shown that: unlike general water level changes in hub downstream, the waterlevel amplitude attenuation along is not obvious in researched reach; Clear the concept of unsteady flow additional velocity、additional slope,through this theory reveals the ship ascending rapids mechanism difficultly under unsteady flow condition. On this basis, proposed channel regulation methods and measures in hub downstream, which provided support for the hub downstream channel regulation.