Grain size spectrum and textural parameters for the fluvial sediment bed in seven tropical rivers of Kelantan, Malaysia are presented in this article. The samples were collected from six tributaries to the main Sungai Kelantan spanning approximately 248 km stretch of water streams. Sand or gravel dominated river was identified for each river using the sediment composition analysis. Textural pattern shows complicated profiles of mean size and no consistent decreasing grain size and gradation parameter were observed towards the downstream flow. Most of the samples fall under the category of either very poorly sorted or poorly sorted and has very platykurtic kurtosis distributions. CM diagram (C=one percentile in microns and M = median grain size in microns) suggested that the deposition of fine-grained sediment for samples with median grain size d50 <1 mm are either by rolling, rolling and saltation or saltation and suspension.
This study investigates the relationship between land use types and sedimentary characteristics of fluvial bed at three
rivers in Selangor, Malaysia; namely Sungai Tengi, Selangor and Langat. The diversity in population density and land
development at the adjacent river banks gives associated dominant land use type as forest, agriculture and urban for
Tengi, Selangor and Langat, respectively. Field sampling was conducted at consistent spatial locations for Tengi and
Selangor, whereas for Langat, the bed sediment was taken at non-uniform spatial points due to limited access. Statistical
analysis of the sediment bed mixture shows that forest dominated land gives finer bed sediment size at < 200 µm.
Agriculture-type of land use increases the mean sediment size to medium sand, whereas bed material near to urbanized
areas has coarser sediment size with > 650 µm. Correlation analysis proved that there is a relationship between types
of land use with the mean sediment size. No distinctive correlation can be observed for sorting, skewness and kurtosis
of the sediment with the types of land use.