Suspended Sediment Flux in Watershed: A Case Study

Suspended sediment flux expresses sediment flow rate as a function of time. It is used for soil erosion control, hydraulic structure design, water resources planning, river studies and water quality assessment. However, most of the above-mentioned tasks are made inaccurately and unreliably, since no sound understanding of sediment temporal distribution is made. In the present paper, an attempt has therefore been made to understand the relationship between flow discharge and suspended sediment concentration during 6 storm events in the Khanmirza watershed comprises ca. 395km2 as a case study. The study aimed to verify high inter and intra variability of suspended sediment concentration within study storms and to roughly assess affecting factors. The flow discharge data were calculated using scale and limnograph while the sediment concentration was measured through sampling and with the help of milk bottle and the depth integration technique with half an hour intervals at the same hydrometry station located at the main outlet of the watershed. The results of field measurements showed that the suspended sediment concentration peak occurs in phase with the hydrograph peak in most of the cases except those ones resulted from specific conditions existed in the watershed. It was also resulted that the sedimentgraphs reach the peak values when the maximum 30-minute intensities of the storm occur.