Handbuch des Wasserbaues

Availability and performance of sediment detachment and transport functions for overland flow conditions

“…As a consequence, the sediment transport rates estimated by using the Low (1989) function were comparable with the measured transport rates, since the equation was based on the same data. Guy et al (1992) tested the applicability of six fluvial transport functions (DuBoys, 1879;Laursen, 1958;Schoklitsch, 1962;Yalin, 1963;Bagnold, 1966;Yang, 1973) for shallow uniform flow with or without rainfall impact. They carried out 207 laboratory experiments in a rectangular flume by using four narrowly graded materials with median grain diameters equal to 0.151, 0.271, 0.328 and 0.381 mm, and their respective particle densities were 1496, 2638, 2647 and 2650 kg m -3 .…”

“…For the condition with rainfall impacting the overland flow the discrepancy ratios were 0.06 for the Yang (1973) function, 0.75 for the DuBoys (1879) function, 0.99 for the Bagnold (1966) function, 1.89 for the Laursen (1958) function, 0.06 for the Yalin (1963) function, and 0.53 for the Schoklitsch (1962) function. Hence, the results showed that the Schoklitsch (1962) function predicted transport rates best for overland flow only, while the Bagnold (1966) function gave the best results for rain impacted overland flow conditions. Govers (1992) evaluated the performance of five existing channel transport functions (Meyer-Peter and Muller, 1948;Yalin, 1963;Yang, 1973;Low, 1989;Lu, 1989) under overland flow conditions.…”

“…Guy et al (1992) evaluated the performance of the selected functions by calculating the discrepancy ratio. The derived mean values of the discrepancy ratio were equal to 0.36 for the Yang (1973) function, 0.54 for the DuBoys (1879) function, 1.49 for the Bagnold (1966) function, 6.12 for the Laursen (1958) function, 0.19 for the Yalin (1963) function, and 0.89 for the Schoklitsch (1962) function for overland flows only. For the condition with rainfall impacting the overland flow the discrepancy ratios were 0.06 for the Yang (1973) function, 0.75 for the DuBoys (1879) function, 0.99 for the Bagnold (1966) function, 1.89 for the Laursen (1958) function, 0.06 for the Yalin (1963) function, and 0.53 for the Schoklitsch (1962) function.…”

“…The derived mean values of the discrepancy ratio were equal to 0.36 for the Yang (1973) function, 0.54 for the DuBoys (1879) function, 1.49 for the Bagnold (1966) function, 6.12 for the Laursen (1958) function, 0.19 for the Yalin (1963) function, and 0.89 for the Schoklitsch (1962) function for overland flows only. For the condition with rainfall impacting the overland flow the discrepancy ratios were 0.06 for the Yang (1973) function, 0.75 for the DuBoys (1879) function, 0.99 for the Bagnold (1966) function, 1.89 for the Laursen (1958) function, 0.06 for the Yalin (1963) function, and 0.53 for the Schoklitsch (1962) function. Hence, the results showed that the Schoklitsch (1962) function predicted transport rates best for overland flow only, while the Bagnold (1966) function gave the best results for rain impacted overland flow conditions.…”

“…Schoklitsch (1962) developed an empirical bed load function for sand bed streams, in which discharge and slope gradient are the main variables:…”