Abstract: Based on the measured hydrology and cross-sectional sedimentation data since operation of Ertan Reservoir, the deposition characteristics are analyzed. The results show that: Ertan reservoir had about 625 million m³ of sediment deposition from 1998 to 2011, most of which was below the dead storage, and the loss of regulating capacity rate was 6.18%. During 1998 to 2000, the annual deposition was about 76 million m³, and during 2000 to 2011 the average annual amount of siltation was approximately 36 million m³. The reservoir sedimentation, shaped in delta, gradually advances towards the dam. From the longitudinal distribution, the sediment deposition in main stream is mainly in the middle part of reservoir. From the horizontal distribution, the deposition is mainly in the main channel. The distance from delta siltation to dam is measured about 66.0 km, and the average elevation of siltation in front of the dam is 1 030.0 m, below the bottom elevation of spillway buildings and intakes. The dam siltation problem would not occur.

Key words: Ertan reservoir, sedimentation, section measurement, characteristics analysis

摘要： 根据二滩水库蓄水运行以来实测水文和泥沙断面测量资料，对水库泥沙淤积特征进行了分析，结果表明：二滩水库1998～2011年泥沙淤积量约6.25亿m3，淤积大部分在死库容以下，调节库容损失率6.18%；1998～2000年蓄水初期年均淤积量约0.76亿m3，2000～2011年年均淤积量近0.36亿m3。水库泥沙淤积以三角洲形态逐渐向坝前推进，从泥沙淤积纵向分布看，干流泥沙淤积主要分布于库中段；从横向分布看，淤积主要集中在主槽。实测三角洲淤积洲头距坝约66.0 km，坝前平均淤积高程为1 030.0 m，远低于泄洪建筑物进口和机组进水口底高程，不会出现坝前泥沙淤积问题。

关键词: 二滩水库, 泥沙淤积, 断面测量, 特征分析