QUANTITATIVE ANALYSIS OF UN-MEASURED BED LOAD AT DIVERSION INTAKES OF THE YELLOW RIVER IN SHANDONG PROVINCE

1 INTRODUCTION At present, most of the instruments used for sampling sediment loads at the canal intakes along the Yellow River in Shandong Province are horizontal samplers. These kinds of samplers cannot sample the suspended load 0.3 m from the riverbed. More recently use of bottle samplers has allowed sampling of the sediment load up to 0.1 m from the riverbed. However, bottle samplers are not able to measure suspended loads with high sediment concentrations and coarse sediment particl…

QUANTITATIVE ANALYSIS OF UN-MEASURED BED LOAD AT DIVERSION INTAKES OF THE YELLOW RIVER IN SHANDONG PROVINCE

Due to limitations of the apparatus for sediment measurement in rivers, the suspended sediment load near the bed cannot be measured. This results in estimates of the volume of sediment entering a canal that are lower than the actual volume, which in turn results in a lack of balance between the net flux of sediment in the canal system and the volume of sediment that settles in it. In this paper, an analysis is presented of the sediment measured in front of and behind the intake gates at the Zhaoqiao, Chengai, Panzhuang, and Liuzhuang sites on the Yellow River. This analysis found that when the concentration in the river ranged between 1-25 kg/m3 the unmeasured sediment is 7.5-11% of the sediment measured in front of the gate and that an additional 5-8% of the grains are bigger than 0.025 mm compared to measurements in front of the gate. This conclusion is useful for correcting previously measured data to more accurately account for the actual volume of sediment entering the canal system. In this paper, the factors influencing the volume of suspended load near the bottom also are discussed including the current pattern and the contour of the bed near the gate entrance and the stage difference between the riverbed and the intake bed. Furthermore, reasons why the quantity of unmeasured sediment near the bottom is large are discussed.