Table 1. Transport Function Output Values

ERDC/CHL CHETN-VII-5

December 2003

have been entered, and secondly, in

Table 1

further studies, it might be useful to

Transport Function Output Values

know more about suspended load

TRIP 1

TRIP 2

estimates as well. These functions are

Capacity Concentration Capacity Concentration

Function

tons/day ppm

The five functions used to compute Toffaleti bed load

175

82.5

bed load are the following: Toffaleti, Yang

Meyer-Peter-Mueller (MPM(1948)), Einstein (total)

Schoklitsch, Einstein bed load, and Ackers-White

Van Rijn bed load. The sediment and Colby

hydraulic data used as input to the MPM (1948)

transport functions are listed in Laursen-Madden 1,998

20

235

3

Table 2. These data were not esti- Laursen-Copeland 3,677

37

852

10

mated, but consisted of actual field Yang D50

measurements. For each trip, they Ackers-White D50 2,156

22

295

3

were collected as closely in time as Schoklitsch (bed)

121.8

1.25

0

possible. This included bottom sam- MPM(1948) D50

ples for the bed gradations and Einstein bed load

653

7

399

5

acoustic data to determine velocity Engelund-Hanson 3,096

32

643

7

profiles and discharge, as well as to Van Rijn

2,215

23

215

2

define the site cross section. The Van Rijn bed load

637.5

126.6

discharge measurements at the study

site are not the same as the flow through L&D 8. This is because the total flow through the lock and

dam includes flow in the main channel, as well as the floodplain and distributaries. A plot of the two

cross sections at the time the measurements were made is shown in Figure 9.

Table 2

Input Data for Transport Functions

Average Sediment Characteristics for Trips 2 and 4

Grain Size

Trip 2

Trip 4

% Finer

mm

% Finer

mm

Flow (cfs)

35,893

31,971

D05

0.18

d50

0.35

Water slope

0.00007

0.00003

D10

0.21

d60

0.44

Water surface

630.38

632.23

D20

0.24

d70

0.78

Cross-section area

15,246

17,485

d30

0.27

d80

1.26

Average channel velocity

2.35

1.83

d40

0.31

d95

1.79

The computed values of bed-load transport, that is, the portion of bed material load estimated or

represented as moving in the sand waves, are shown in Figure 10.

Regarding this study, two important results shown in this graph need to be emphasized. The first is

that the magnitudes of the transport rates fall within the same range as ∆q computed using ISSDOT.

For trip 2, when the line in Figure 5 is extrapolated as shown, its highest values are in the range of

600 to 800 tons per day. For Trip 4, the highest values are right at 600 tons per day. The low values

12