辽东半岛东岸碧流河口潮间带柱状样沉积物粒度特征及其环境意义  

GRAIN SIZE CHARACTERISTICS AND ENVIRONMENTAL SIGNIFICANCE OF COLUMNAR SEDIMENTS IN THE INTERTIDAL ZONE OF BILIU ESTUARY ON THE EAST COAST OF LIAODONG PENINSULA

作　　者：张威[1] 苏世兵 李宁[1] ZHANG Wei;SU Shi-bing;LI Ning(School of Geographical Sciences,Liaoning Normal University,Dalian 116021,Liaoning,China)

机构地区：[1]辽宁师范大学地理科学学院,辽宁大连116021

出　　处：《云南地理环境研究》2021年第2期37-44,共8页Yunnan Geographic Environment Research

基　　金：辽宁省特聘教授项目“辽南地区黄土记录的风沙活动与海平面变化”(60618006).

摘　　要：粒度是反映沉积动力特征的重要参数。潮间带作为陆地与海洋的过渡地带,其沉积物在输移和沉积过程中记录了丰富的沉积环境信息。在辽东半岛东岸碧流河口口外海滨段潮间带浅滩采取2根柱状样沉积物(BLH1、BLH2)进行粒度分析,通过图解法、对比法分析碧流河口潮滩柱状样沉积物粒度变化特征,并指出其环境意义。结果表明:(1)BLH1、BLH2粒度组成相似,均以砂质粉砂与粉砂质砂为主。砂含量均值为40.6%,粉砂含量均值为52.6%,黏土含量均值为6.8%,平均粒径均值为4.7Φ。(2)频率分布曲线主要呈现不对称双峰且偏向粗颗粒一侧,概率累积曲线形态变化相似,跳跃组分含量最高,且跳跃组分还可细分为两段,说明该区域水动力条件较强,沉积环境多变。(3)沉积物粒度自下而上呈现由粗到细的趋势,这可能与碧流河输送的泥沙在河口附近不断淤积并向海推进,导致潮滩高程逐渐升高、水动力逐渐减弱有关,而表层沉积物有粗化现象,可能与辽东半岛沿岸泥沙流及其东北西南向的潮流方向有关。研究区沉积物粒度特征与径流来沙、所在陆源与岛礁基岩风化有关;沉积过程受潮流波浪动力及人类活动的影响。Grain size is an important parameter reflecting the characteristics of sedimentary dynamics.As a transitional zone between land and sea,the intertidal zone records abundant information of sedimentary environment in the process of transportation and sedimentation.Two columnar sediments(BLH1,BLH2)were collected from the intertidal shoal outside the mouth of Biliu estuary on the east coast of Liaodong Peninsula for grain size analysis.The grain size variation characteristics of columnar sediments in the tidal flat of Biliu estuary were analyzed by graphic method and comparison method,and its environmental significance was pointed out.The results show that:(1)BLH1 and BLH2 are similar in grain size composition,and are mainly sandy silt and silty sand.Average sand content is 40.6%,average silt content is 52.6%,average clay content is 6.8%,and average particle size is 4.7Φ.(2)The frequency distribution curve mainly presents asymmetric bimodal and inclines to the coarse particle side.The shape change of probability accumulation curve is similar,and the jump component content is the highest,and the jump component can be subdivided into two sections,which shows that the hydrodynamic conditions in this area are strong and the sedimentary environment is changeable.(3)The grain size of sediment shows a trend from coarse to fine from bottom to top,which may be related to the sediment transported by Biliu River continuously silting up near the estuary and advancing toward the sea,resulting in the elevation of tidal flat gradually increasing and the hydrodynamic force gradually weakening,while the surface sediment is coarsened,which may be related to the sediment flow along the Liaodong Peninsula and its tidal current direction in the northeast and southwest direction.The grain size characteristics of sediments in the study area are related to runoff sediment,land source and bedrock weathering of islands and reefs Sedimentation process is influenced by tidal wave dynamics and human activities.

关 键 词：沉积物 粒度 沉积环境 辽东半岛 碧流河口 

分 类 号：TV148.1[水利工程—水力学及河流动力学]