三峡大学学报（自然科学版）2011，Vol.33Issue(6)：27-32,6.
矩值法和图解法计算山区河流沉积物粒度参数的差异
The Difference between Moment Method and Graphic Method for Calculating Grain-size Parameters of Sediments in Mountain Streams
摘要
Abstract
Taking a set of sediment samples which consist of coarse sand and very coarse sand with preponderant grain-size from a mountain stream named Liantuo in Yichang area, then on the basis of grain size analysis with the sieve analysis method, to calculate the grain-size parameters of sediments with the moment method and graphic method separately; the results of the two different methods are compared. The average grain diameters and sorting coefficients of the two methods are very close; they could almost replace each other. The kurtoses of the two sets of data have a correlation but they couldn't replace each other; but the skewness of them is dispersed; they didn't have an obvious correlation with each other. Analysis proved that the reason which created the difference has a relationship with the counting principle of the two different methods and the grain composition of the coarse grained sediments. The coarse grain skewness calculated by the two methods don't have an obvious correlation with each other; the skewness values derived from the graphic method has indicated the tail of grain-size; while the skewness value derived from the moment method has reflected the whole characteristics of grain-size. For the kurtosis values derived from the two methods, when the fractiondistribution curve of the sample is unimodal and centralized, the difference between the results derived from the two methods are insignificant; while when the fraction distribution curve of the sample is double-apices and the times peak frequency value is comparatively high; the results derived from the two methods are quite different. The calculation of the graphic method doesn't take the grain-size characteristics of the tails of both ends into consideration; it may lead to calculating error of the grain-size parameters, however, the moment method is more scientific and the calculating results are more exact. So in the process of integrating and assimilating the information, the difference lies in the calculation of the grain-size parameters derived from the two methods should be taken into account.关键词
粒度参数/图解法/矩值法/粗粒沉积物Key words
grain size parameter/graphic method/moment method/coarse grained sediments分类
天文与地球科学引用本文复制引用
陶敏,邓山,王婷乐,袁金钊,肖尚斌..矩值法和图解法计算山区河流沉积物粒度参数的差异[J].三峡大学学报（自然科学版）,2011,33(6):27-32,6.基金项目
中国博士后特别资助基金(200801440) （200801440）
湖北省青年杰出人才基金(2008CDB382) （2008CDB382）
