Statistical Analysis in Fluvial Sediments of Selangor Rivers: Downstream Variation in Grain Size Distribution

Statistical analysis and downstream variation in the fluvial sediment mixture were studied along three different rivers in Selangor i.e. Sungai Langat (Sg. Langat), Sungai Selangor (Sg. Selangor) and Sungai Tengi (Sg. Tengi). The aim of this study is to analyse the changes in grain size distribution in the downstream direction in three different classes of rivers, less, medium and fully development along the river banks. Samples were spatially and systematically collected at a distance about 3-5 kilometers between each point. Sediments were dried, sieved and further characterised using the GRADISTAT software. Results showed that the mean size of bed materials in Sg. Selangor and Sg. Langat were decreasing along the downstream towards the estuary. Meanwhile, an opposite trend was obtained for Sg. Tengi where the mean size of the bed material was found increasing towards the downstream of Sg Tengi’s river mouth. Different variation was also observed for sediment parameters of sorting and skewness which reflect decreasing of sediment size follow the downstream of the rivers. Furthermore statistical analysis of kurtosis showed that there were no variation occurs along the three rivers where most of the sediment mixture is a mesokurtic type, normal distribution of bed sediment sizes. Beside that statistical analysis also show from the bivariate plots indicate that the sediments are mostly medium sand, poorly sorted and has profile of either symmetrical or fine skewed.