2. Medium to very coarse sand-bed rivers (0.250 mm < D50 < 2.00 mm)
For this bed material, Toffaletti with RD = 0.93, Laursen with RD = 0.60, and Bagnold with
RD = 1.68 compute Cppm closest to measured values. On the other hand, based upon
Pearson correlation coefficient, Karim with Cc = 0.66 followed by Brownlie with Cc = 0.60 best
correlate measured concentrations of sediment as compared to measured values.
3. Very fine to fine sand-bed rivers (0.062 mm < D50 < 0.250 mm)
The most suitable equations are Karim and Kennedy with RD = 0.90, Karim with RD = 1.28,
Brownlie with Cc = 0.58, and Toffaletti with Cc = 0.52.
4. Silt-bed rivers (0.004 mm < D50 < 0.062 mm)
For silt-bed rivers, Einstein with RD = 1.06, Bagnold with RD = 0.56, Toffaletti with Cc =
0.48, and Brownlie with Cc = 0.38 are the most acceptable relationships.
5. Small rivers (width ≤ 10 m and depth ≤ 1 m)
The closest results obtained in small rivers is Brownlie with RD = 1.18, Karim with RD =
1.19, Yang with Cc = 0.85 and Toffaletti with Cc = 0.79.
6. Intermediate rivers (10 m < width ≤ 50 m and 1 m < depth ≤ 3 m)
For intermediate rivers, Toffaletti with RD = 0.94, Brownlie with RD = 0.94, Karim with Cc =
0.76, and Yang with Cc = 0.70 are the most acceptable relationships.
7. Large rivers (width > 50 m and depth > 3 m)
For large rivers, Bagnold with RD = 1.04, Laursen with RD = 1.13, Brownlie with Cc = 0.80,
and Shen and Hung with Cc = 0.76 are the most acceptable relationships. It should be noted
that for silt-bed rivers and for very fine to fine sand-bed rivers, the Yellow River contributes
about 77 and 63 percent of the data, respectively. As reported by many investigators, this
river is an extremely heavily sediment-laden river and floods experience hyperconcentrations
of sediment. Out of all rivers, this river system is unique and therefore should not be
categorized as a common alluvial river.
From the analysis, it can be seen that both Ackers and White and Toffaletti have a tendency
to increase the computed concentration of suspended sediment, as the median diameter of
bed material becomes finer. This tendency also occurs with these relationships when the
river size increases. As reported by Kodoatie et al. (1999), the applicability of the ten
selected sediment transport relations based upon comparison between measured and
computed sediment transport rates and results from other studies are summarized in Table
B.4.
B.14
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