For the existing situation 16
Descriptions of simulation scenarios for the existing master plan of Tam Quan port are summarized as follows:
1) SC1_PLO: Simulate the hydrodynamic conditions and bottom topography changes in Tam Quan area with the current topography condition in the Southwest
2) SC2_PLO: in Tam Quan area with the current topography condition in the Northeast monsoon jimulate the hydrodynamic conditions and bottom topography changes period
3) SC3_PLO: Simulate the hydrodynamic conditions and bottom topography changes in’Tam Quan area with the current topography condition in the Northeast monsoon period when the area is affected by a large flooding combination (assuming the flood of P=5% from 16" to 21" November, 2005),
Detailed results ofthe simulated scenarios are shown in Appendix B
For the new master plan n
Descriptions of simulation scenarios for the new master plan of Tam Quan fishing port are summarized as follows
1) SC4_PLI: Simulate the hydrodynamic conditions and bottom topography changes, in Tam Quan area with the topography condition given in the new master plan in the Southwest monsoon period
2) SCS_PLA: Simulate the hydrodynamic conditions and bottom topography changes in Tam Quan area with the topography condition given in the new master plan in the Northeast monsoon period,
3) SC6_PLA: Simulate the hydrodynamic conditions and bottom topography changes in Tam Quan area with the topography condition given in the new master plan in the Northeast monsoon period when the area is affected by a large flooding combination (assuming the flood of P = 5% from 16" to 21" November, 2005)
Detailed results of the simulated scenarios are shown in Appendix C
Model extracted locations n
To analyze and assess the hydrodynamic regime of Tam Quan port area so that it satisfies the ctiteria of port planning and design, the regimes of waves, currents and deposition or erosion in the port area, channel routes and anchorage areas of boats and ships need to be analyzed, The analysis will be carried out simultaneously for both in the existing master plan and the new master plan.
‘The calculated results are extracted on the small domains in Tam Quan port area about the wave field, current field and bed level change field Moreover, in this study, to the variation of water level and current speed, ten of representative points along the channel routes are selected and extracted (TI2TIO) To assess the bottom topography changes, ten representative eross-scctions of the channel routes are selected and extracted (S1-1=S10-10) The extracted locations ofthe model results are shown in Figure 4.1 and Table 4.1
Figure 4.1 The bathymetry of new master plan and the extracted locations of the results from Mike 21/3 EM model
Table 4.1 The extracted co-ordinates of the results from Mike 21/3 FM model
No | Point Section, ——— œY) Starting point Ending point
Hydrodynamic assessments of Tam Quan port area based on riteri
42.10 srion 1 Avoid flooding in the port land area
Simulated results from the total current model of the existing master plan and the new master plan in ease of appearing big floods with frequency of P = 5% combining with flood-tide in the Northeast monsoon period are shown in Figure 42, The caleulated results of the flooded area of the plans are shown in Table 4.2 To compare the change in water level in the port land area, the results of water level line at 10 points along the channel routes are extracted and summarized as mentioned in Figures 4.3 and Table 44
With the plan of current topography of Tam Quan port area, most of the Tam Quan port area is flooded (see Figure 4.2-T) According to the summarized result in Table
4.2, the total flooded area is up to 515,758 m*on the total port land area of 689,870 mì accounting for about 75% The highest water level is +1.62 m in the upstream area of
‘Thien Chanh bridge Along the area from the downstream of Thien Chanh bridge to the jetty foot (point B ~ near the Border post) the highest water level fluctuates from +144 m to +1.27 m, From the jetty foot, the water level begins to reduce from +1.27 m (o only 40.39 m at the jetty head (approximately the flood-tide peak) At the jetty middle section, the highest water level reaches #0.73 m, lo) SC3_PLO
161050 sim Kn lo) 00.00 10112015 Time Step 82 of 132 im
21000 Em im (0:00:00 1012013 Time Step #2 of 12
075-090 tái 0% đãu be đôi 1s Untied Vale nem 00
Figure 4.2 Water level in the port area during the flood peak period (at 0:00 AM.
October 11", 2013) with the existing master plan (T) and the new master plan (B)
‘With the plan of dredged channel route and leveling the grounds at the port land area under the new plan, the flood water level at the port area decreases significantly from
56279 em and the ability of flood flushing is better than the custent condition (see Figure 4.2-B) The entire flood discharge is drained to the sea estuary, and the port land area is not flooded The highest water level is +0.83 m in the upstream area of
‘Thien Chanh bridge Along the area from the downstream of Thien Thanh bridge to the jetty foot, the highest water level oscillates from +0.78 m to 40.71 m From the jetty foot, the water level begins to reduce from 40.71 m to only +0.38 m at the jetty head (approximately the flood-tide peak) AL the jetty middle section, the highest water level reaches +0.47 m,
Table 4.2 The summarized result of the flooded area of the plans
‘The existing master plan | The new master plan
No | Zones 2 Flooded Flooded (mẺ) | flooded 3 | flooded area (m*) area (m*)area (%) area (%)
Total 689,870 | 515,758 75 0 o hwnd dan nai TC TP
Figure 4.3 Comparison of water level between SC3_PLO and SC6_ PL] at 10 points
Table 4.3 Results of water level at locations in the flood season (SC3_PLO&SC6_PLI)
Min | Max | Mean | Min | Max | Mean
‘The plan of dredging the channel route and leveling the grounds atthe port land area as in the proposed new plan is satisfied with the ability of draining floods, meeting the criteria of flooding in the port land atea, However, the elevation for leveling the
‘ground under the formula of calculating the pier surface elevation needs to be calculated and checked again to make sure its reavonability.
Calculating the pier surface elevation and the ground leveling area as the formula (3-1,
VMNCTK : the designed high water level (m), from Table 4.3
'VMNCTK = +0.78 m; fa: the reserved height by preserving goods and process of loading and unloading (m), choose a = 1.40 m.
However, the pier surface elevation under the present plan is +2.20 m Hence, the elevation for leveling the grounds at the port land area as in the proposed new plan of 42.20 mis proper
4.2.2 Criterion 2 To ensure ealm wave condition in the port
Both periods of the Northeast monsoon and Southwest monsoon, wave proy from the offshore into Tam Quan port area under the impact of the topography and shoaling makes the wave height and wave direction decrease when entering the coastal area, The waves when going into the coastal area to the critical point will be broken and cause the wave stress which will be the major cause to create a coastal current due to the waves The regions with the big wave stress will create the big currents and vice versa, On that bas c, after calculating the coastal wave Id and wave stress, the current system generated due to the waves at the coastal area is calculated.
‘The model results show that whatever the offshore waves starting from any directions, when going into the estuary area also change their directions into the southe: direction and approach deeply in the channel route.
4 In the Southwest monsoon period
‘The wave fields of the Southwest monsoon of the existing master plan and the new
‘master plan are basically the same Only the AB channel route is different due to dredging the channel bottom (see Figure 4.4) With the existing condition, the AB channel route has relatively uniform wave spectrum; at the location of channel head (point A), the wave height is about 0.55 m; at the channel end (point B), the wave height dc nesto 0105 m and itis absolutely destroyed With the new master plan, the
AB channel route has uneven wave spectrum, and the wave has a trend of going more deeply into the channel; at he channel head, the wave height is about 0.55 m; from the
‘middle of channel route inwards, the wave height is higher insignificant compared with the existing condition; atthe channel end, the wave height declines to 0.10 m and it is absolutely destroyed.
Figure 4.4 Significant wave height field in the Southwest monsoon period with the
‘existing master plan (L) and the new master plan (R) b In the Northeast monsoon period
In the Northeast monsoon period, wave propagation from the offshore into Tam Quan estuary area, when passing Truong Xuan cape, waves change their directions into the southeast direction and come in the AB channel The wave fields of the Northeast monsoon of the existing master plan and the new master plan are basically the same. Only the AB channel route is different due to dredging the channel bottom (see Figure 4.5) With the existing condition, the AB channel route has relatively even wave spectrum; a the location of channel head (point A), the wave height is about 1.05 m; at the channel middle, the wave height declines to 0.30 m and itis absolutely destroyed at near the channel end (point B) With the new master plan, the AB channel route bay uneven wave spectrum, and the waves have a trend of going more deeply into the
‘channel; at the channel head, the wave height is about 1.05 m; at the middle of channel route, the wave height is about 0.40 m; atthe channel end, the wave height declines to0.15 m and itis absolutely destroyed. existing master plan (L) and the new master plan (R)
Table 4.4 The summarized results of the wave height in Tam Quan port area
‘The existing master plan | The new master plan joa — | The fishin ‘The fishin
No | Period rhea mean oom ort an tan
„ h ‘channel Mã channel se route route
Because the value of [H] not only specifies forthe whole port area, but it also mainly specifies for the anchorage area (0 ships handling of goods or storm shelter area Therefore, with the summarized results in Table 44, the fishing port areas and anchorage areas completely ensure the criteria of the ealm wave condition inthe port However, the actual situation at the first-half area of AB channel route, boats and ships on and out the port having many difficulties due to the monsoon wave height greater than 0.30 m; especially the Northeast monsoon wave (with HE, > 1.05 m) hit on board
‘causing maritime unsafety Therefore, it is necessary to take measure to adjust or supplement the coastal training structures such as the jetty oF groin as to ensure the circulation of boats and ships.
4.2.3 Criterion 3 To ensure permissible currents for ship maneuvering
4 In the Southwest monsoon period
Proposal of adjusted measure of the port entrance in order to fulfill port design
Based on the result of analysis and assessment of hydrodynamic conditions and mechanism of sedimentation and erosion in Tam Quan port area as at the previous item, the author would like to propose the following adjusted plan:
- Basically, retaining the plan of new overall ground, just building to last and add the jetty routes to reducing waves and preventing sands at the channel gate with the total length of L = 1,270 m, arranged as in Figure 4.17, including the following items: the north jetty with the length of Ly = 580 m and the south jetty with the length of Ls = 690 m The distance between the jetty heads is about 300 m;
= Simultaneously, dredging the channel gate area close to the edge of Truong
‘Xuan mountains to the depth of -4.5 m, the area of about 25 ha.
With this measure, the author expects that the result will improve the existing problems of the approved new master plan; moreover, the 25 ha water area will be {taken full of advantages to make the anchorage area for large, medium sized ships to anchor in the future.
1609100 200 293000 94000 295000 round and the main current directions Figure 4.17 The adjusting plan g
Proceeding to establ th the Mike 21 model and calculate similarly for 03 further scenarios to evaluate the effect of the adjusted master plan compared with the new er plan, Descriptions of simulation scenarios are described as follows:
1) SC7_PI Simulate the hydrodynamic conditions and bottom topography changes in Tam Quan area with the topography condition of the adjusted master plan in the Southwest monsoon period.
2) SC8_PL2: Simulate the hydrodynamic conditions and bottom topography changes in Tam Quan area with the topography condition of the adjusted master plan in the Northeast monsoon period
3) SC9_PL2: Simulate the hydrodynamic conditions and bottom topography change in Tam Quan area with the topography condition given in the adjusted master plan in the Northeast monsoon period when the a s affected by a large flooding combination (assuming the flood of P = 5% from 16 to 21"
Detailed results ofthe simulated scenarios are shown in Appendix D.
4.3.2 Analysing the results of the adjusted measure
43.2.1 Criterion 1 Avoid flooding in the port land area
With the new master plan which is calculated and analyzed previously, the flooding criterion in the port land area is satisfied, However, after having the measures of the plan adjustment, the author also recalculates the total hydrodynamic model to check again the satisfaction of this criterion, Calculated results are shown in Figure 4.18 and Table 4.5, mì SC9 PL2
Figure 4.18 Water level in the port area during the flood peak period (at 0:00 AM
October 11%, 2013) with the adjusted master plan
Table 4.5 Results of water level at locations in the flood season (SC6_PLI&SC9_PL2)
Min | Max | Mean | min | Max | Mean |
The results show that the water level field in the port area of this adjusted master plan is similar to the new master plan which was previously calculated, The highest water level in this case is lower about 0,06 m than in the case of new masterplan, Building newly or stretching the jetty route and dredging the channel gate area also has a small effect on stopping the flood current, helping the flood drainage more conveniently; the flood flow when running into the AB channel route is directly pushed through the channel gate to reach the sea, So, the adjusted master plan is completely satisfactory With this eritrion,
43.2.2 Criterion 2 To ensure calm wave condition in the port
In this part, the author recaleuates the spectral wave model in both periods of the Southwest monsoon and Northeast monsoon forthe adjusted masterplan, The result of
‘wave height field is presented in Figure 4.19.
Figure 4.19 Significant wave height field in the Southwest (L) and Northeast (R)
‘monsoon periods with the adjusted master plan Inthe Southwest monsoon period, because the stretched south jetty route prevents, the waves are propagated straightly into the channel gate and then spread in the water area near Truong Xuan cape At the location of new channel gate the wave height is about 0,60 m Close to the mountain edge, the wave height reduces to 0.25 m In the AB
‘channel route, the wave height is less than 0.10 m About 90 % of the water area inside the channel gate has the wave height of less than 0.50 m,
In the Northeast monsoon period, because the newly consructed north jetty route prevents, the wave height in the channel gate area and the water area behind the jetties is smaller than the new master plan, When passing the north jetty head, the waves are4iffracted from the channel gate into the inside water area so the wave height reduces significantly The wave height in the channel gate area is about 0.80+1.00 m, Toward the location of the AB channel route head, the wave height reduces to still 0.15 m and then diminished The total water area inside the channel gate has the wave height of less than 0,50 m and about 95% of the water area has the wave height of less than 0.50
Therefore, with the layout of the channel route and channel gate as in the adjusted
‘master plan, boats and ships goes in and out the port relatively favorable in both periods of the Southwest monsoon and Northeast monsoon Simultaneously, we also can take advantage of about 90% of the water area near Truong Xuan cape to make the anchorage area for large, medium sized ships The adjusted master plan also is completely satisfactory with this criterion,
4.3.2.3 Criteria 3 To ensure permissible currents for ship maneuvering
The calculated results of the total current model in both periods of the Southwest monsoon and Northeast monsoon for the adjusted master plan are alternatively presented in Figures 4.20 & 4.21 m v ơ volo ae amm
MUG han a CS ‘er ea
Figure 4.20 Spring current field (T) and ebb current field (B) in the Southwest
‘monsoon period with the adjusted master plan
In the Southwest monsoon period, according to the result in Figure 4.20, it shows that the coastal current field has the main direction from the south to the north, The Tongshore currents run from the south up, their current directions are pushed away far the channel gate by the stretched south jetty route and then they run around the north jetty, With the flood currents the current speed is relatively small At the channel gate, the current speed reaches about 0.05 mvs, In the water area which is enclose by the new jetty routes, the current speed is very small, only about 0022005 mvs The narrow AB channel route is the place with higher current speed, about 0.1020.15 mis, With the ebb currents, the current speed in this area increases, the highest is in the AB
‘channel route which reaches 0,250.35 m/s Thanks to the stretched south jetty section wilh its shield, the ebb currents have the straight direction out to the channel gate The
‘current speed at the channel gate and in the water area near Truong Xuan cape is only about 0,05+0.10 mis,
Figure 4.21 Spring current field (T) and ebb current field (B) in the Northeast monsoon period with the adjusted master plan
In the Northeast monsoon, according to the result in Figure 421, it shows th the coastal current field has the main direction from the north to the south The longshore currents run from the north down, when coming Truong Xuan cape with the large current speed of about 0.50 mvs, the cuerent is shielded by the new north jetty system and directed far the channel gate and then run slong the shore in the North-South direction, With the flood currents, the current speed inside the channel gate is relatively small, The total channel route and water area inside the channel gate, the current speed is about 0.05 mvs; locally, along the stretched south jetty section, the current speed only reaches 0.30 mis With the ebb currents, the current speed in this area increases The highest is about 0.25+0.35 mvs in the AB channel route and along the stretched south jetty section The current speed at the channel gate and in the water area inside gate is only about 0.05=0.10 mis,
Therefore, in both periods of the Southwest monsoon and Northeast monsoon, the current speed of the adjusted masterplan reduces more than the approved new master plan, The current speed at the channel gate and in the water area inside the gate is relatively small so itis not energetic enough to form the eddy The highest current speed in the areas of channel gate, channel route and the water area inside the gate is less than 0.35 mis All are satisfactory with the eritera for the ship's permissive speed on the channel, With w„„, = 0.35 m/s < V„., = 1.50 mis.
4.3.2.4 Criteria 4, Avoid deposition to maintain channel depths
With this adjusted master plan the evolution of the bottom sedimentation and erosion a Tam Quan port area is calculated and simulated in 01 month in both periods of the
‘Southwest monsoon and Northeast monsoon, and in 06 days in the Northeast monsoon period when happening a large flood (P = 5%) combined with flood-tide The results of bed level change are presented in Figures 4.22 & 4,23 xin) ⁄ | Pa
{0001112015 Tae ip 750750. sco PL2 to
Figure 4.22 Total bed level change in a month in the Southwest (T) and Northeast (M)
‘monsoon periods and in the flood season (B) with the adjusted master plan i i i a ẹó b we ro TƯ HH nẽ: ae a a =. é
Figure 4.23 Comparison of bed level change between the new master plan and the adjusted master plan at 03 cross-sections along the AB channel route