小浪底水库2008—2009年调水调沙排沙比分析

Analysis on Sediment Delivery Ratio of Regulated Discharge Regime of the Xiaolangdi Reservoir in 2008-2009 Period

针对小浪底水库2008年、2009年汛前调水调沙期间排沙比差异悬殊这一情况,从小浪底水库入库水沙过程和淤积形态两个方面分析了原因。结果表明:2008年后汛期入库沙量少,淤积三角洲上坡段纵比降小、抗冲性较强,造成2009年塑造的人工异重流初始动力较2008年同期小;2009年调水调沙期间河道自然来水少,异重流形成后后续入库流量小、持续时间短,异重流后续动力严重不足。在现有条件下,建议综合考虑三门峡、小浪底水库减淤效益,科学调配三门峡水库下泄流量过程,合理分配小浪底水库异重流和后续输送水量,尽快建设古贤等水利枢纽。

The paper analyzes the reasons of great difference of sediment delivery ratio occurred during regulated discharge regime before flood season of 2008 and 2009 of the Xiaolangdi Reservoir from two aspects of silt-discharge process of the reservoir inflow and the morphology of sedimentation.The outcomes show that a) the incoming sediment during flood season after 2008 is not much,the longitudinal slope of upper section of deposited sandbar is small and resistance to scour is greater,causing the initial power of artificial density current created in 2009 is smaller than that of in 2008 and;b) during the regulated discharge regime period conducted in 2009,the reservoir inflow is small,sustained period is short and follow-up power of density current is seriously insufficient after the formation of density current.Under the existing conditions,it suggests to comprehensively consider the benefits of sediment reduction of Sanmenxia and Xiaolangdi,scientifically regulate the discharging process of Sanmenxia Reservoir,rationally allocate the water for density current and subsequent delivery of the Xiaolangdi Reservoir and build Guxian Key Water Control Project as soon as possible.