流溪河水库沉积物粒度的时空分布及其沉积动力学意义  

Spatial and temporal distributions of sediment grain size and their implications for depositional dynamics in Liuxihe Reservoir

作　　者：王艳杰[1] 唐红渠[1] 姜仕军[1] 

机构地区：[1]暨南大学生态学系/水体富营养化与赤潮防治广东普通高校重点实验室,广州510632

出　　处：《生态科学》2015年第3期1-6,共6页Ecological Science

基　　金：广东省科技计划重点项目(2013B080500022);NSFC-云南联合重点基金(U1033602)

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。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.

关 键 词：沉积物粒度分析 水动力 沉积环境 流溪河水库 

分 类 号：Q149[生物学—生态学]