古今洪水沉积粒度参数的对比分析  

Contrastive Analysis on Grain Size Parameters of Ancient and Modern Flood Deposits

作　　者：史威[1] 陈炜[2] 

机构地区：[1]江苏教育学院地理系,江苏南京210013 [2]中国科学院南京地理与湖泊研究所,江苏南京210008

出　　处：《山东科技大学学报（自然科学版）》2012年第5期78-85,共8页Journal of Shandong University of Science and Technology(Natural Science)

基　　金：国家自然科学基金项目(90411015);江苏教育学院"十一五"规划基金项目(Jsjy2009zd05)

摘　　要：通过对长江上游重庆段中坝和玉溪古今洪水沉积物的平均粒径(Mz)、分选系数(So)、标准离差(Sd)、偏度(Sk)和尖度(KG)等参数,以及沉积物粒度概率累积曲线分析,认为:①研究区古今洪水层是上游过境洪水和当地洪水共同作用的结果,反映了长江上游大范围区域性洪水现象;②古洪水尤其是史前时期的古洪水并不比现代洪水规模大,现代洪水沉积物的粒度偏粗除与水动力条件有关外,还与现代洪水形成的下垫面生态环境退化有关;③古今洪水沉积物粒度参数的对比分析,不仅要与同流域同河段对比,还要注意干支流不同地貌部位沉积环境的差异。The grain size parameters of ancient and modern flood deposits such as Mz,So,Sd,KG and cumulative grain size distribution curves in Zhongba and Yuxi sites of the upper reaches of the Yangtze,show that：①the ancient and modern flood deposits in the two sites should be the outcome of combined actions of the transit flood from the upper reaches and the local flood,which reflect the phenomenon of the large-scale regional flood in the upper reaches of the Yangtze;②as to the scale,the paleoflood,especially formed in prehistoric times,may be not much larger than the modern flood,except the hydrodynamic condition,the little coarse deposits from the modern floods may be in relation to the ecological degradation in the underlying surfaces;③with regard to the contrastive analysis on grain size parameters of ancient and modern flood deposits,not only should we pay close attention to the comparability of the common basin and the common reach,but also the variation of sedimentary environment of main and branch waterways especially different physiognomy positions.

关 键 词：长江上游 古洪水沉积 现代洪水沉积 粒度参数 

分 类 号：TV632.63[水利工程—水利水电工程]