Study On Artificial Methods For Depressing Tongguan Riverbed Elevation

Rising of Tongguan riverbed elevation indicates decrease of capacity of SanMenXia reservoir and rising of lower reaches of Wei River, and produces potential threatening to safety and social developing in this region. The present research helps to achieve reasonable operational style of SanMenXia reservoir and high-efficiency management, and to decrease disasters of flood. Experimental methods and measured results for sediment-removal using high-speed water jet are valuable to related researches on sand transportation.Experimental methods and measured results are first introduced in the paper. Based on a lot of practical measured results, present artificial methods for sediment-removal are analyzed, and machinery efficiency and corresponding results of sediment-removal practice from 1996 to 1999 are discussed. It is shown that the present methods are rather effective.There are many factors may influence the Tongguan riverbed elevation. Tongguan riverbed elevation is basically stable before the construction of SanMenXia reservoir. During the period for increasing water storage, rising of Tongguan riverbed elevation is mainly due to operational style. During the period of operational control that keeps clean water in the reservoir and discharge the sand, operational elevation is main factor. Variation of flow conditions in the upstream is also an important factor resulting in elevationrising. Effective methods for depressing Tongguan riverbed elevation includes improving operational style of the reservoir and suspending sand using water jet produced by machinery.