Regression methods for evaluation of the underwater noise levels in the Slovenian Sea
| 11 dic 2021
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Article Category: Original Scientific Article
Publicado en línea: 11 dic 2021
Páginas: 17 - 27
Recibido: 12 jul 2021
Aceptado: 15 jul 2021
DOI: https://doi.org/10.2478/rmzmag-2021-0003
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© 2021 Andreja Popit, published by Sciendo
This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.
Significant independent variables with p-values less than 0.05, meaning that there was a more than 95 % probability that these variables were related to the dependent variable Leq,125Hz. The grey fields indicate insignificant independent variables with p-values greater than 0.05. The abbreviation n.a. means not applicable.
| 0.000 | 0.000 | 0.000 | 0.000 | 0.000 | |
| 0.019 | 0.509 | 0.111 | 0.867 | 0.599 | |
| 0.097 | 0.022 | 0.000 | 0.033 | 0.000 | |
| 0.000 | 0.000 | 0.000 | 0.215 | 0.002 | |
| 0.001 | 0.000 | 0.000 | 0.033 | 0.000 | |
| 0.256 | 0.110 | 0.036 | 0.000 | 0.000 | |
| n.a. | 0.000 | n.a. | n.a. | n.a. | |
| n.a. | n.a. | 0.021 | n.a. | n.a. |
Examples of underwater noise levels related mainly to the ship traffic in the global seas and oceans.
| Scotian Shelf, Canada, hydrophone depth of 31 m and water depth of 79 m [3] | 1972–1985 | Winter average noise levels at zero wind speed [3]: |
Ramsey Sound, Pembrokeshire, West Wales, UK, hydrophone depth of 20 m and a water depth of 460 m [7] | 2009 | Sound pressure levels [7]: 92.6 dB re 1 μPa ± 3.9 dB re 1 μPa during spring 104.7 dB re 1 μPa ± 2.2 dB re 1 μPa during summer 85.9 dB re 1 μPa ± 2.4 dB re 1 μPa during spring 104.6 dB re 1 μPa ± 2.4 dB re 1 μPa during summer |
| India, shallow water, hydrophone depth of 5 m and water depth of 25 m [4] | 2006 | Average noise levels [4]: |
Guanabara Bay, SE Brazil, hydrophone depth of 2 m and a water depth of 4 m [8] | 2011–2012 | The highest mean sound pressure level [8]): |
| Indian Ocean, the lagoon of a coral atoll, hydrophone depth of 2–15 m and water depth of 50 m [5] | 2005 | Spectral maxima observed at 1 kHz and 7.5 kHz [5]: |
Port of South Louisiana (H-3), Port of Houston (H-1), NE Gulf of Mexico, hydrophone depth from 250–1,370 m [9] | 2010–2012 | The highest values |
| Northeast Pacific Ocean, SW of the San Nicolas Island, California, USA, hydrophone depth of 1,090–1,106 m [6] | 1966 – 2006 | Mean ambient noise levels: |
Celtic Sea, northern and southern North Sea in UK, hydrophone depth of 100 m and a water depth of 200 m [10] | 2013–2014 | Median noise levels for 1/3 octave bands from 63 Hz to 500 Hz [10]: |
Regression equations in which the dependent variable Leq,125Hz was predicted by the significant independent variables (ρL,2NM, ρL,5NM, ρL,Trieste, ρL,Venice, dreadg. act., clean. act., vv and hp).
| 13.02.2015–05.05.2015 | |
| 26.09.2015–31.12.2015 | |
| 18.08.2016–01.11.2016 | |
| 06.07.2017–07.08.2017 | |
| 18.08.2018–31.12.2018 |
Significant independent variables with p-values lower than 0.05, meaning that there was a more than 95 % probability that these variables were related to the dependent variable Leq,63Hz. The grey fields indicate insignificant independent variables, with p-values greater than 0.05. The abbreviation n.a. means not applicable.
| 0.000 | 0.000 | 0.000 | 0.000 | 0.000 | |
| 0.001 | 0.061 | 0.240 | 0.923 | 0.010 | |
| 0.005 | 0.691 | 0.048 | 0.003 | 0.036 | |
| 0.007 | 0.015 | 0.000 | 0.556 | 0.000 | |
| 0.327 | 0.794 | 0.000 | 0.119 | 0.000 | |
| 0.037 | 0.087 | 0.023 | 0.342 | 0.000 | |
| n.a. | 0.000 | n.a. | n.a. | n.a. | |
| n.a. | n.a. | 0.002 | n.a. | n.a. |
The Pearson correlation coefficients between the dependent variable (Leq,63Hz) and the independent variables (ρL,2NM, ρL,5NM, ρL,Trieste, ρL,Venice., dreadg. act., clean. act., vv and hp) in all measuring periods.
| 0.58 | 0.51 | 0.54 | 0.39 | 0.35 | |
| −0.02 | 0.06 | 0.08 | 0.08 | 0.07 | |
| 0.13 | −0.06 | 0.05 | −0.04 | 0.05 | |
| 0.06 | −0.06 | 0.02 | 0.09 | 0.08 | |
| −0.02 | −0.03 | 0.08 | 0.12 | 0.12 | |
| −0.10 | −0.05 | −0.05 | 0.01 | −0.11 | |
| n.a. | 0.31 | n.a. | n.a. | n.a. | |
| n.a. | n.a. | −0.10 | n.a. | n.a. |
Multiple correlation coefficients (r) between dependent variables (Leq,63Hz and Leq,125Hz) and independent variables (ρL,2NM, ρL,5NM, ρL,Trieste, ρL,Venice, dreadg. act., clean. act., vv and hp) in all measuring periods.
| 0.59 | 0.55 | 0.57 | 0.40 | 0.40 | |
| 0.41 | 0.21 | 0.59 | 0.29 | 0.23 |
The Pearson correlation coefficients between the dependent variable (Leq,125Hz) and the independent variables (ρL,2NM, ρL,5NM, ρL,Trieste, ρL,Venice, dreadg. act., clean. act., vv and hp) in all measuring periods.
| 0.39 | 0.18 | 0.55 | 0.24 | 0.15 | |
| −0.02 | 0.01 | 0.09 | 0.04 | 0.02 | |
| 0.11 | 0.06 | 0.07 | 0.02 | 0.12 | |
| 0.05 | 0.05 | −0.04 | 0.17 | 0.02 | |
| −0.02 | 0.02 | 0.01 | 0.18 | 0.04 | |
| −0.08 | −0.01 | −0.09 | −0.01 | −0.10 | |
| n.a. | 0.10 | n.a. | n.a. | n.a. | |
| n.a. | n.a. | −0.10 | n.a. | n.a. |
Coefficients of determination (R2) between the dependent variables (Leq,63Hz and Leq,125Hz) and the independent variables (ρL,2NM, ρL,5NM, ρL,Trieste, ρL,Venice, dreadg. act., clean. act., vv and hp) in all measuring periods.
| 0.35 | 0.30 | 0.33 | 0.16 | 0.16 | |
| 0.17 | 0.05 | 0.34 | 0.09 | 0.05 |
Regression equations in which the dependent variable Leq,63Hz was predicted by the significant independent variables (ρL,2NM, ρL,5NM, ρL,Trieste, ρL,Venice, dreadg. act., clean. act., vv and hp).
| 13.02.2015–05.05.2015 | |
| 26.09.2015–31.12.2015 | |
| 18.08.2016–01.11.2016 | |
| 06.07.2017–07.08.2017 | |
| 18.08.2018–31.12.2018 |