Sediment load in a river is composed of bed load and suspended load. Central Water Commission (CWC) regularly measures suspended load (gms/litre) at their river gauging sites. Bed load is more difficult to measure and requires the use of bed load samplers.
Computation:
Sediment yield (tons/ha) from a river basin during a given time period can be computed using the Universal Soil Loss Equation and its derivatives. Inputs required are rainfall, slope, soil type, land use, etc.
The Soil and Water Assessment Tool (SWAT) hydrological model implements this equation and can be conveniently used to map out the spatial distribution of soil loss in the basin.
Usually sediment load does not arrive to rivers as quick as we think, but they are in several retention points across the basin. They can mobilize in function of their size, composition (mineral /organic composition) as well as of the local rain pattern. Be sure that you are considering those aspects to get a good account of this load. This is a very important measure in watershed management issues.
Actually u can use musle formula to determine the sediment yield, here's is some guidence for you :https://www.researchgate.net/publication/279456544_CALCULATION_OF_RUNOFF_AND_SEDIMENT_YIELD_IN_THE_PISEVSKA_RIJEKA_WATERSHED_POLIMLJE_MONTENEGRO
(PDF) CALCULATION OF RUNOFF AND SEDIMENT YIELD IN THE ...