Figure 6 Distribution of the median sediment grain size between HYK and GC in the LYR.
In the braided reach (between HYK and GC), the median grain size of the bed material decreases gradually from HYK to GC, and the grain size of sediment in the main channel is generally larger than that in the floodplain (see Figure 6). The average median particle sizes of the bed material in the main channel and floodplain are approximately 0.1 mm and 0.05 mm, respectively, corresponding to dry bulk densities ranging from 1.233-1.410 t/m3and 1.121-1.249 t/m3, respectively (Shao & Wang, 2005). Considering the characteristics of the fine sediment particle size in the LYR, the dry bulk densities of the bed material in the main channel and floodplain are 1.233 and 1.121 t/m3, respectively. The scouring and silting mass in the braided reach during the period 2000 - 2017 can be calculated.