摘要: |
根据1982–1995年在浙江沿岸椒江口、杭州湾、象山县大目涂取得的沉积柱样层序 数据系列和重复沉积界面测量序列,利用分形理论进行沉积过程及冲淤幅度的分析。沉积过程和沉积地层层序存在自相似结构,两者之间在无特征尺度区存在着初始值以及分数维的传递。椒江河口和杭州湾南侧潮汐通道边坡沉积柱样泥层厚度的分数维在1.2–1.5之间。按潮汐沉积基本单元形成时间为大小湖周期计算,沉积过程1年重现期的高程均方变幅为3–28cm,10年重现期为10–167cm,50年重现期为21–575cm。分形特征是了解沉积地层序列、分析沉积界面波动过程极值分布规律的途径之一。 |
关键词: 分形 沉积作用 波动 河口海岸 |
DOI:10.11693/hyhz200001014014 |
分类号: |
基金项目:浙江省自然科学基金资助项目,494007号和香港裘搓基金1996-1997年度访问学者资助项目 |
附件 |
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FRACTAL REPRESENTATION AND ANALYSIS OF DEPOSITIONAL PROCESSES AND SEQUENCE |
LI Yan, CHEN Xi-tu, XIA Xiao-ming, LI Bo-gen
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Second Institute of Oceanography, SOA, Hangzhou 310012
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Abstract: |
It is shown in the present contribution that the scale invariance appears both in time series and depositional sequences linked with a similar fractal dimension. Sedimentary records from the estuary of the Jiaojiang River, inter-tidal area and tidal channels adjacent to the Hangzhou Bay were analyzed. Their fractal dimension ranged between 1.2 and 1.5 not only in sedimentary processes but also in depositional sequences. Taking into account the fractal dimension and initiator derived from muddy layer sequence and assumed that the initiator is dominated by spring and neap tidal cycle, the mean square fluctuation range of sedimentary series was calculated. In the study areas the range was 3–28cm for one-year return periods, 10–167cm for ten-year return periods and 21–575cm for fifty-year return periods. The fractal properties might be useful to distinguish the ranges of erosion or deposition events with different cycles. |
Key words: Fractal, Sedimentation, Fluctuation, Coast and estuary |