ESTIMATION OF BEDLOAD TRANSPORT INTO GURARA WATERSHED USING GRAIN SIZE DISTRIBUTION DATA

17 Jun, 2024,

Abstract > Volume 7, Number 1 (2021) > UGBALA, E.N.; SUNDA Y, I.N.; ALIYU A.D. & OBIOMAH K.O.download full paper

ABSTRACT

An improvised scoop was used to take bed material samples from the six (6) gauging sites located on each of the inflowing rivers into Gurara dam reservoir in the Gurara Watershed.  Sampling verticals of ¼, ½, ¾ width of the river cross-section were used and the average of the mixture was taken to the laboratory for sieve analysis to obtain the grain size distribution of the bed materials.  The analyses of the grain size distribution showed that the bed load accounted for 13% of the total suspended sediment load of 22,254,820 kg/year in the Gurara Watershed.  The geometric mean particle size ( D50) D60 , D30 and  D10 were calculated.  The uniformity coefficient and coefficient gradations of the six inflowing rivers10 were calculated which ranged from 0.542mm to 1.146mm and showed that the soils are poorly/uniformly graded.  The 13% of the total suspended load should be used as bed load estimate for sedimentation studies in the Watershed and neighbouring watershed with similar hydrology.  This simple method should be encouraged for estimating bed load transport in other basins.

KEYWORDS: Bed load, Sediment load, Sieve Analyses, Gurara Watershed, Transport.

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