摘要
基于赣江河漫滩相沉积序列的415个样品,利用分形理论分析了沉积物的粒度分形特征,并对比了平均粒径等传统粒度指标重建的洪水事件序列。研究结果表明,无标度区范围相关系数R2的平均值由0.75提升至0.82,沉积物分维值D的平均值为2.34,说明沉积物粒度分布的分形特征较好。分维值D与传统粒度指标中的平均粒径、偏态、粘土含量存在显著正相关关系,与砂和粗粉砂含量存在显著负相关。在洪水期,沉积物的粒度偏大,砂的含量较多,分维值D偏小,非洪水期正好相反。在辨识出的18个洪水年份中,分维值D可辨识出15个洪水年份,达到了83.3%,这表明了粒度的分维值D在基于河漫滩沉积序列的古洪水重建中有一定的应用潜力。
The grain size fractal of sediment was studied based on 415 samples of Ganjiang River floodplain sedimentary sequence.It is compared with the flood event sequence reconstructed by traditional granularity index such as average particle size.The results show that the mean value of the correlation coefficient in the scale-free range is increased from 0.75 to 0.82,and the mean value of fractal dimension of sediment is 2.34,which demonstrates that the fractal characteristics of sediment granularity distribution are better.The fractal dimension is positively correlated with the mean particle size,skewness and clay content,and significant negative correlation with the sand and coarse silt content.In flood period,the grain size of sediment is larger,the content of sand is more,and the fractal dimension is small,but the non-flood period is just the opposite.The fractal dimension can identify 15 flood years in the 18 flood years identified,and the identification rate is 83.3%.This indicates that the fractal dimension of grain size distribution has potential in flood event reconstruction based on floodplain sedimentary system.
作者
曹向明
万智巍
贾玉连
方淑华
郑丽匀
李晓峰
CAO Xiang-ming;WAN Zhi-wei;JIA Yu-lian;FANG Shu-hua;ZHENG Li-yun;LI Xiao-feng(Key Laboratory of Poyang Lake Wetland and Watershed Research Ministry of Education,School of Geographyand Environment,Jiangxi Normal University,Nanchang 330022,China)
出处
《水电能源科学》
北大核心
2019年第11期83-86,10,共5页
Water Resources and Power
基金
江西省重大生态安全问题监控协同创新中心项目(JXS-EW-00)
国家自然科学基金项目(41262007)
鄱阳湖湿地与流域研究教育部重点实验室(江西师范大学)开放基金(ZK2013003)
江西省教育厅科学技术研究项目(170209)
关键词
河漫滩沉积
粒度特征
分形理论
洪水事件
赣江
fluvial sediment
characteristics of grain-size
fractal theory
flood events
Ganjiang River
