黄河设计沙量的内涵与确定方法刍议OA

Designed sediment load is a key parameter for major planning and key project demonstration in the Yellow River Basin,typically represented by the multi-year average sediment load at main stem and tributary cross-sections over a future period.The duration of the future period for designed sediment load shall be determined based on the demands of target applications.For major water control projects or river-crossing structures,the period should exceed the designed service lifespan of the project;For the demonstration of alternative sea-outlet chan-nels or the formulation of sediment storage space plans for floodplain areas,a time scale of hundreds of years shall be adopted.For the future 30-50 years designed sediment load,hydrological and genetic methods are recommended for joint estimation and cross-validation to determine a reasonable range.For centennial or multi-centennial estimates,phased calculation is suggested by dividing the period into the short term(within 50 years)and the long term(beyond 50 years).Long-term estimation should focus on the sediment reduction effects of terraces,man-made horizontal terraces,and large Qinghai-Tibet Plateau reservoirs such as Longyangxia.