【摘要】 排沙比是水库拦截泥沙程度的指标之一。排沙比越大,水库淤积强度就越小;反之亦然。以三峡水库2004-2012年库区各水文站的实测资料为依据,通过对三峡水库运行以来水库排沙比及其影响因素的分析,发现坝前水位和入库、出库流量是影响水库排沙比大小的主要因素,其次是入库沙量和泥沙颗粒大小。进一步分析得出排沙比对月均库水位变化的敏感度随月均入库流量的增加而迅速增加,当月均入库流量小于15 000 m3/s时,月均库水位变化对排沙比几乎没有影响。当月均入库流量大于20 000 m3/s时,水库排沙比的变化幅度随月均库水位的变化较大,当月均库水位从138 m增加到155 m时,其排沙比约从62%降低至不到10%。为了提高水库排沙比,在水库调度上建议采用"大水低位、小水高位"的运行方式。更多还原

【Abstract】 Sediment excluding rate is one of the indicators of deposition degree in a reservoir. The larger the sediment excluding rate is,the smaller the deposition intensity in a reservoir. In this study,the influence factors of sediment excluding rate in the Three Gorges Reservoir was analyzed,based on the observed data at each hydrologic station in the Three Gorges Reservoir area from 2004 to 2012. It was considered that the water level at the dam,along with the inflow and outflow of the reservoir,were the main factors affecting the sediment excluding rate of the reservoir,followed by the sediment inflow,and particle size. Moreover,the sensitivity of the sediment excluding rate to average monthly water level changes increased rapidly with the increase of the average monthly inflow of the reservoir. When the average monthly inflow of the reservoir was less than 15,000 m3/s,the average monthly water level changes had small impact on the sediment excluding rate. However,when the average monthly inflow was larger than 20,000 m3/s,the sediment excluding rate of the reservoir changed greatly,and the average monthly water level increased from 138 m to 155 m,while the sediment excluding rate was reduced from 62%,to less than 10%. Therefore,in order to improve the sediment excluding rate of the reservoir,an operational mode of "low level for abundant water,high level for scarce water"was recommended for future scheduling of the reservoir.更多还原