EMPIRICAL STATISTICAL RELATIONS OF SEDIMENT DEPOSITION IN THE LOWER YELLOW RIVER
黄河下游泥沙淤积的经验统计关系

A systematical study has been made on the relation between the sediment deposition in thelower Yellow River and the incoming water and sediment conditions, especially on the deposition ofsediments in different grain size fractions, leading to the establishment of a series empirical statisticalrelations, which can be used to estimate the tendency of variation in the sedimentation of the lowerYellow River. Based on these empirical relations, a quantitative assessment can be made on the con-tributions of sediments in different grain size fractions to the sedimentation in the lower Yellow Riv-er. The coarser sediments (>0.05mm) have a much larger influence on the lower Yellow RiverSedimentation than that of total sediments. Given the water discharge, when the coarser sedi-ments increase 1t, the sedimentation of the lower Yellow River will increase 0.842 t, 71.1% higherthan the increase in sedimentation in the case when the total sediments increase 1t. If the incomingwater and sediment quantities remain the same, and the percentage of coarser sediments increase by0.05, the sedimentation in the lower Yellow River will increase by 69.5 million t. The empirical re-lations indicate a positive correlation between the total sediment deposition and the percentage ofcoarser sediments(>0.05mm) or the sediments in 0.05 mm -0.025 mm fraction, but a negativecorrelation for the sediments finer than 0.025 mm. This demonstrates that the depositional behaviorof sediments in different grain size fractions is different.