【摘要】 分别采用Camsizer XT型动态图像仪和LS 13 320型激光粒度仪进行长江口沉积物粒度测试,并对测试结果进行分析比对。动态数字图像仪的测量结果重复性比激光粒度仪好,其测得的等效球径(X_area)和激光法测量值更接近,且比投影宽度(X_{c min})和激光法测量值更稳定。两种方法粒度测量结果基本一致,粒度参数相关性好;动态图像法在大颗粒测量上更准确,而激光法在亚微米颗粒测量上更具优势;动态图像法的测量结果具有更丰富准确的粒度和粒形数据,并且测量时间短、效率高。以崇明东滩南北近岸为例,将动态数字图像法应用于沉积物分析,结果表明:北部以细粉砂和极细粉砂为主,滩地略淤积,南部则以细砂和粗粉砂为主,滩地微侵蚀;北部沉积物分选性比南部好,峰度值比南部大,偏度值差别不大,大多表现为极正偏;向外沉积物颗粒变粗,球形度和宽长比变好,且南部的球形度和宽长比的变幅比北部大。更多还原

【Abstract】 In this paper,samples of sediment taken from the Yangtze Estuary have been measured by dynamic image analyzer Camsizer XT and laser particle analyzer LS 13 320,and the results obtained from the two methods have been compared and analyzed respectively. Two testing methods were adopted to test the reproducibility,and the results show that the variability of statistical parameters of the dynamic image analysis is lower than that of the laser particle size analysis. It also shows that the reproducibility of results from Camsizer XT is more satisfactory. In the present study,the Xareaobtained from the dynamic image analysis is closer to the results of the laser particle size analysis,and is more stable than the X_{c min} and the results of laser particle size analysis. The two methods have acquired almost the same measurement results of particle size,and the relevance of the particle size parameters is rather good,and the measurement results of large particles through dynamic image analysis are more accurate than those of the other method. In addition,the laser method is superior to the dynamic image analysis method in the measurement of submicron particles. The measurement results of the dynamic image analysis method are more abundant and accurate in particle size and shape than those of the laser method,and the dynamic image analysis method can achieve higher efficiency than the laser method. The grain size analysis of sediment samples in the north and south nearshore of Chongming Dongtan shows that the composition of sediment in the north is coarse clay and fine silt,while in the south is coarse silt and fine sand. There is slight siltation in the north Chongming Dongtan,while,on the contrary,the south has been slightly eroded. The sediments in the northern part have better sorting and higher kurtosis than in the south,while the skewness is approximate to each other,and the sediments in both north and south show positive skewness.As for the outward sediments,the grain size is becoming coarser and the sphericity and the symmetry are becoming better. Furthermore,the variation of sphericity and symmetry in the south was larger than that in the north.更多还原