中文摘要：

重建水库建库以来的沉积环境演变过程对水库管理具有重要意义。以流溪河水库4个沉积物柱状样为研究对象,分析沉积物的粒级组成及粒度参数特征。结果显示：（1）流溪河水库自建库以来,沉积速率经历了＂高—低—高—低＂的演变规律;（2）河流是水库的主要沉积物来源,沿入库口至大坝方向,水动力逐渐减弱,沉积颗粒呈现＂由粗到细＂的空间变化特征;（3）入库口（S3）主要受河流水动力作用影响;库湾区（S8）远离入库口,反映了稳定的湖心沉积环境;过渡区（S4和S6）受河流搬运营力、再沉积作用及库区消落带侵蚀的共同作用,呈现由＂双峰向单峰＂的变化,反映了上述三种主要营力互为消长的演变过程。

英文摘要：

Reconstruction of depositional history is of great importance to reservoir management. Grain size distributions and their parameters in sediments of 4 cores from the Liuxihe Reservoir were studied to infer the sedimentary history over the past 60 years. The results are as follow：（1） Sedimentation rates display a ＂high-low-high-low＂ variation pattern over the maturation process of the reservoir.（2） Fluvial transportation made the largest contribution to sediments. The grain size decreased from river entrance to the dam, which indicates a weakening in hydrodynamic force and carrying capacity of the water flow.（3） Gain size pattern in riverine zone（e.g., Site S3） is mainly controlled by hydrodynamics of the inflowing river; while in lacustrine zone where water flow is weak（e.g., Site S8）, deposition of suspended particles dominates the sedimentation process. Sediments from the transitional zone（Sites S4 and S6） showed a change in size pattern from unimodal to dual modal, which possibly responded to a combination of influences by river transportation, surface soil reworking and erosion of water fluctuation zone, as well as the temporal variation in each agent.