Noise Survey for marine traffic noise
1. Location
1.1 The noise survey for the marine traffic noise was carried out at the existing temporary Wholesale Fish Market at Sam Shing Estate.
2. Date
and Time
2.1 The noise survey was carried out on 16 May 2001 between 05:00 to 07:00 hours.
3. Personnel
3.1 Dr. Mohamed Hasnain Isa (Senior Consultant)
Mr. Gary Yim (Scientific Officer)
4. Instrumentation
4.1 Type 1 sound level meter, SLM (Rion NA27) and Calibrator (Rion NC73) were used to perform the noise survey.
5. Weather
and Sea Conditions
5.1 The wind was calm. Air temperature was 25 oC and the sea condition was calm during the noise survey period.
6. Survey
Procedure
6.1 The SLM was placed on the breakwater, at a height of 1.2m above ground surface and at a height of approximately 3m above the water surface. The SLM was positioned at a place with no sound reflecting objects in its vicinity. It was pointed perpendicularly to the course of the vessels and sampans.
6.2 The perpendicular distance from the side of the fishing vessels, and the side of the sampans to the SLM was about 30m and 25m, respectively.
6.3 The SLM was calibrated immediately prior to and after the noise survey measurement.
6.4 Noise measurement was conducted for three fishing vessels and five sampans passby during the noise survey period. The measurement location was near the entrance of the typhoon shelter. The fishing vessels and sampans were travelling at a fairly steady speed as they approach the entrance and slow down when it enters the shelter. Therefore, the travelling speeds of the fishing vessels and sampans during the measurement were considered typical of that normally used near or inside the typhoon shelter. The highest measured noise data from fishing vessels and sampans were extracted for the marine traffic noise assessment.
6.5 The maximum A-weighted sound pressure levels (Lmax) recorded during the passage of the vessel and sampan were noted.
6.6 The marine traffic noise survey record sheet are attached.
7. Noise
Survey Result
7.1 The highest Lmax levels recorded during the survey are shown as below:
The highest Lmax level recorded from the
noise survey:
|
Vessel
Type |
Measurement
Distance, m |
Lmax,
dB(A) |
|
Sampan |
25 |
66.6 |
|
Fish Vessel |
30 |
67.7 |
|
Monitoring Location |
Exiting temporary Wholesale Fish Market (WFM) |
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Date of Monitoring |
16-5-01 |
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Time (hh:mm) |
0500 – 0700 |
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Weather Condition |
Clear Sky, 25oC |
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Wind Speed |
Calm |
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Sea Condition |
Calm |
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Investigators |
Gary Yim & Mohamed Hasnain Isa |
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Sound Level Meter (Model, S/N) |
Rion, NA27 |
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Calibrator (Model, S/N) |
Rion, NC 73 |
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Calibration |
Before: 94.0 dB(A) |
After: 94.0 dB(A) |
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Measurements Results |
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Measurement
Point |
Location of
Measurement
|
Noise
Levels dB(A) |
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|
Leq |
Lmax |
Lmin |
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|
Fish
vessel – Traveling Distance
25m |
At the parking area beside the WFM |
60.2 |
62.2 |
57.6 |
|
|
Fish
vessel – traveling Distance
30m |
Dam |
55.6 |
64.1 |
52.9 |
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Fish
vessel – traveling Distance
30m |
Dam |
65.9 |
66.6 |
61.6 |
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|
Sampan
traveling Distance
40m |
Dam |
53.4 |
54.6 |
52.3 |
|
|
Sampan
traveling Distance
30m |
Dam |
54.5 |
63.6 |
50.9 |
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|
Sampan
traveling Distance
30m |
Dam |
56.5 |
62.3 |
50.6 |
|
|
Sampan
traveling Distance
25m |
Dam |
61.4 |
67.7 |
51.2 |
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Sampan
traveling Distance
30m |
Dam |
56.6 |
64.8 |
53.9 |
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