Environmental Engineering Reference
In-Depth Information
Table 7.6. Total amount of sediment deposition over the first 1 000 m of the canal after 0,
30, 60 and 90 days.
Widening
Widening
Deposition over 1 000 m
Days
No control
Deepening
B
=
12 m
B
=
14 m
Volume of sedimentation (m
3
)
0
0
0
0
0
Volume of sedimentation (m
3
)
30
1 639
4 032
3 645
4 890
Volume of sedimentation (m
3
)
60
2 225
6 272
5 632
8 998
Volume of sedimentation (m
3
)
90
2 499
6 605
5 964
9 826
160
140
120
100
80
60
40
20
0
1000
2000
3000
4000
5000
Distance (m)
6000
7000
8000
9000
10000
0
Figure 7.11. Changes in the
actual and equilibrium
concentration after 30, 60 and
90 days for a canal with no
sedimentation control.
C-eq at 30 days
C-act at 30 days
C-eq at 60 days
C-act at 60 days
C-eq at 90 days
C-act at 90 days
behaviour in sediment deposition and changes in concentration (see Table
7.6). Widening of the canal (
B
14 m) leads in this example to the small-
est equilibrium concentration. However after some time the equilibrium
concentration for the two scenarios will be in line with the concentration
of the canal without control measures (see Figures 7.11, 7.12 and 7.13).
The simulation results of the deposition due to the deepening of the
canal are shown in Figure 7.12, which gives the actual sediment load
and the equilibrium concentration for Scenario 1 (deepening) after 30,
60 and 90 days. When the sediment trap is almost empty the equilib-
rium concentration is very low, after 30 days the trap is partly filled
and the equilibrium concentration increases; after 60 days the value is
the same as in the situation without measures to control the sediment
deposition (Case 1). The sediment trap (4 500 m
3
) will be filled in about
30 days, and after that the sediment will be deposited on the modified
canal bottom in the same way as in the canal without control measures.
=
Search WWH ::
Custom Search