Abstract:

In the present paper, we analyzed the fluvial process and the effect of riverbed protection of key points in the downstream of Three Gorges Project. In line with the characteristics of low water level at Yichang station, we selected Yanzhiba, Nanyangji and Lujiahe as the key points for controlling, and analyzed their fluvial processes as well as their impact on the water level at Yichang station based on prototype observation. Moreover, we carried out long-term monitoring on the effect of riverbed protection at Yanzhiba. Results reveal that measures including blocking deep groove by dumping stones and protection with geosynthetics mattress with concrete block has apparent effect of protection and anti-erosion for riverbed, and at the same time roughens the riverbed for backwater effect, which somehow restrains the water level decreasing at Yichang station.

Key words: river reach downstream of dam, fluvial process of key points, water-level decreasing, riverbed protection project