The Port Works Division has been maintaining a long-term wave monitoring programme since 1994. Two monitoring stations have been set up in the harbour near Kau Yi Chau and at the West Lamma Channel. The collected wave data is used to set up wave models for predictions of extreme wave conditions in the harbour for the design of marine structures.

The following parameters are provided from the outputs of the recorders :

The average recorded water depths at Kau Yi Chau and West Lamma Channel wave stations are respectively about 9m and 10m. A summary of the wave measurement is given below.

Wave Measurement at Kau Yi Chau Station (1994-2022)

Year Time in Service (%) Calm Period (%) (Hmo<0.3m) Average Hmo (m) Average Tp (s) Maximum Hmo (m) [Tp (s)] Maximum Recorded Hmax (m) Wave Data
1994 78% 63% 0.31 6.74 1.46 [9.14] 2.45 KYC_1994
1995 87% 77% 0.26 6.47 1.51 [11.63] 2.68 KYC_1995
1996 60% 75% 0.27 6.33 1.57 [11.63] 2.38 KYC_1996
1997 95% 79% 0.26 6.65 1.61 [11.63] 2.68 KYC_1997
1998 97% 81% 0.24 6.38 1.40 [9.14] 2.92 KYC_1998
1999 93% 75% 0.25 6.15 2.37 [9.85] 3.75 KYC_1999
2000 100% 73% 0.27 6.38 1.70 [9.14] 2.33 KYC_2000
2001 73% 70% 0.29 6.29 2.68 [10.67] 3.87 KYC_2001
2002 96% 79% 0.26 6.12 2.46 [11.64] 3.42 KYC_2002
2003 85% 78% 0.27 6.30 2.68 [12.8] 3.44 KYC_2003
2004 86% 69% 0.28 5.63 1.33 [6.67 & 9.53] 2.13 KYC_2004
2005 84% 58% 0.31 5.62 1.73 [13.21] 2.65 KYC_2005
2006 72% 58% 0.32 6.04 2.47 [11.7] 3.83 KYC_2006
2007 51% 40% 0.35 5.26 1.75 [3.95] 2.83 KYC_2007
2008 67% 39% 0.41 5.32 3.31 [12.26] 5.31 KYC_2008
2009 79% 39% 0.52 5.11 3.34 [12.26] 5.45 KYC_2009
2010 80% 60% 0.37 5.05 2.89 [3.64] 4.82 KYC_2010
2011 94% 78% 0.17 4.90 2.29 [10.72] 3.52 KYC_2011
2012 86% 77% 0.18 5.08 2.59 [10.5] 4.14 KYC_2012
2013 76% 81% 0.15 4.99 1.72 [11.98] 2.70 KYC_2013
2014 58% 61% 0.31 5.42 2.07 [3.66] 3.35 KYC_2014
2015 75% 11% 0.47 4.50 1.86 [10.95] 2.96 KYC_2015
2016 55% 70% 0.16 4.56 0.97 [8.57] 1.55 KYC_2016
2017 54% 65% 0.23 5.55 1.36 [10.95] 2.13 KYC_2017
2018 66% 54% 0.30 6.16 4.32 [14.32] 6.80 KYC_2018
2019 81% 63% 0.29 6.06 1.35 [10.5] 2.11 KYC_2019
2020 59% 26% 0.38 5.83 1.65 [7.56] 2.47 KYC_2020
2021 97% 7% 0.44 5.38 1.34 [9.64] 2.28 KYC_2021
2022 77% 10% 0.45 5.12 2.62 [10.77] 3.83 KYC_2022

Wave Measurement at West Lamma Channel Station (1994-2022)

Year Time in Service (%) Calm Period (%) (Hmo<0.3m) Average Hmo (m) Average Tp (s) Maximum Hmo (m) [Tp (s)] Maximum Recorded Hmax (m) Wave Data
1994 84% 55% 0.33 7.51 1.68 [9.14] 2.42 WLC_1994
1995 53% 46% 0.36 7.29 1.45 [3.88] 2.47 WLC_1995
1996 41% 56% 0.32 7.08 1.71 [11.63] 2.83 WLC_1996
1997 71% 60% 0.28 6.66 2.52 [5.82] 3.99 WLC_1997
1998 34% 51% 0.32 7.99 1.08 [12.8] 1.93 WLC_1998
1999 51% 50% 0.33 7.34 3.28 [9.85] 4.68 WLC_1999
2000 72% 38% 0.38 6.49 1.95 [9.85] 3.01 WLC_2000
2001 77% 45% 0.35 6.60 3.03 [10.67] 4.01 WLC_2001
2002 27% 52% 0.33 7.40 2.29 [10.67] 3.41 WLC_2002
2003 78% 45% 0.36 6.64 3.38 [12.8] 5.45 WLC_2003
2004 75% 32% 0.37 6.36 1.59 [10.29] 2.57 WLC_2004
2005 89% 43% 0.35 6.89 2.01 [11.98] 3.11 WLC_2005
2006 77% 41% 0.37 7.29 2.99 [10.95] 4.64 WLC_2006
2007 82% 47% 0.34 6.95 2.29 [5.97 & 7.79] 3.69 WLC_2007
2008 95% 41% 0.36 7.24 3.49 [13.93] 5.46 WLC_2008
2009 97% 34% 0.36 7.19 2.81 [11.19] 4.47 WLC_2009
2010 99% 39% 0.33 6.87 1.33 [10.10] 2.24 WLC_2010
2011 72% 54% 0.29 6.07 2.81 [13.56] 4.34 WLC_2011
2012 88% 60% 0.22 5.94 0.72 [5.97] 1.18 WLC_2012
2013 99% 75% 0.15 5.45 1.79 [11.19] 2.84 WLC_2013
2014 99% 51% 0.28 6.41 2.47 [11.7] 3.89 WLC_2014
2015 75% 52% 0.27 6.57 1.76 [10.09] 2.77 WLC_2015
2016 90% 39% 0.36 6.73 2.08 [5.83] 3.40 WLC_2016
2017 67% 29% 0.39 6.58 1.65 [10.72] 2.61 WLC_2017
2018 71% 48% 0.31 6.16 4.37 [14.73] 6.81 WLC_2018
2019 81% 34% 0.35 6.55 0.94 [7.67] 1.49 WLC_2019
2020 43% 16% 0.43 6.56 1.43 [12.02] 2.39 WLC_2020
2021 95% 8% 0.44 6.74 1.79 [12.14 & 9.98] 2.52 WLC_2021
2022 99% 14% 0.46 6.61 2.51 [11.29] 3.55 WLC_2022
Note
  1. The time in service refers to the time at which the recorder is operational.
  2. % of calm period refers to the time in service.
  3. The peak period Tp of the maximum Hmo, is shown in square brackets.


The wave measurement over these periods reflected that the prevailing wave directions in the measurement locations are the south and southeast, and extreme wave heights are generally aligned with the presence of tropical cyclone events. It should be noted that the recorded spectral significant wave height Hmo at these two wave stations may be taken to be approximately the same as the significant wave height H1/3 for design purpose. More details of these data can be obtained from Civil Engineering and Development Department if required.

For further information about the wave measurements at the two monitoring stations mentioned above, please contact Senior Engineer/District (rwmyuen@cedd.gov.hk or 2762 5553) of the Port Works Division.