mag

Malaysia Water Research Journal
4.3 Hydrodynamic Model
The hydrodynamic modelling only considered the tidal effect. Based on the
hydrodynamic modeling, the average current speed in the study area is 0.1 - 0.8
m/s which the highest speed occured at the estuary. Results also showed that
the maximum current speed for the study area is 1.8 m/s and along the river it
reaches up to 0.7 m/s. The current speed was lower in the ocean compared to
the river with a difference of 0.2 m/s. Modelling of the study area for the projected
sea level rise for 2020 with 0.034 m show increment in current speed. The average
current speed is expected to be 0.15 - 0.85 m/s. Analysis for 2020 showed the
estuary has the highest current speed of 0.85 m/s while the river recorded an
average flow velocity of 0.3 - 0.5 m/s. The maximum current speed in Kuala
Pahang reaches up to 1.8 m/s and the river can go up to 0.9 m/s. Projected sea
level rise of 0.144 m in year 2060 predicted that the study area will experience
an increase of average current speed between 0.2 - 0.88 m/s. Statistical analysis
showed the maximum current speed of the study area can reach between 0.8
- 1.9 m/s.
Projected sea level rise of 0.307 m in year 2100 showed the average current
speed in Kuala Pahang ranges between 0.3 - 0.9 m/s and can reach a maximum
speed of between 0.6 - 1.9 m/s. The maximum difference of current speed at
the estuary showed increment of 0.1 - 0.2 m/s while the island area, meanders
of the river and the southern estuary experienced a decline of 0.06 - 0.1 m/s.
Models comparison for 2020 and 2014 show an increment in the average current
speed to 0.02 - 0.04 m/s and the maximum speed can go to 0.02 - 0.1 m/s.
The analysis also showed a reduction in the current speed between 0.001 - 0.02
m/s. Comparison of model years 2060 and 2014 show the average difference
between the current speed 0.02 to 0.05 m/s and the maximum difference is
0.05 to 0.06 m/s. The analysis also showed that the area recorded a decrease
in current speed between 0.02 to 0.05 m/s near the island and south of Kuala
Pahang. Comparative analysis of model for years 2100 and 2014 shows the
study area having increment in the average current speed between 0.03 to 0.18
m/s in the estuary and a slight decrease in the average current speed in the
river and southern estuary of 0.01 m/s. See Table 3 for the predicted average
and maximum current speed, residual current speed for the prospective years
discussed here. The residual current speed at the estuary mouth for the future
years was calculated based on the variation between the predicted sea level
and the base level obtained on year 2014. The residual current speed profiles are
shown in Figure 7.
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Institut Penyelidikan Hidraulik Kebangsaan Malaysia (NAHRIM)
National Hydraulic Institute of Malaysia (NAHRIM)