• Title/Summary/Keyword: Lunar periodicity

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Decomposition of Wave Components in Sea Level Data using Discrete Wavelet Transform (이산형 웨이블릿 변환을 통한 조위 자료 내 파고 성분 분리)

  • Yoo, Younghoon;Lee, Myungjin;Lee, Taewoo;Kim, Soojun;Kim, Hung Soo
    • Journal of Wetlands Research
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    • v.21 no.4
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    • pp.365-373
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    • 2019
  • In this study, we investigated the effect of wave height in coastal areas using discrete wavelet transform in Taehwa river basin in Ulsan. Through the decomposition result of tide data using daubechies level 7 wavelet and Curve Fitting Function, we confirmed that detail components of d3 and d4 were semidiurnal and diurnal components and approximation component(a6) was the long period of lunar fortnight constituent. The decomposed tide data in six level was divided into tide component with periodicity and wave component with non-periodicity using autocorrelation function and fourier transform. Finally, we confirmed that the tide component is consisted 66% and wave component is consisted 34%. So, we quantitatively assessed the effect of wave on coastal areas. The result could be used for coastal flood risk management considering the effect of wave.

Effects of the lunar cycle in the catch composition and total catch of stationary lift nets in the coastal waters of Miagao, Iloilo, the Philippines

  • Vergara, Christopher John C.;Quinitio, Gerald F.;BAECK, Gun Wook
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.53 no.4
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    • pp.349-356
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    • 2017
  • The catch composition of commercially important species of the stationary lift net at Barangay Gines, Miagao, Iloilo, the Philippines was investigated from December 2013 to May 2014 during the different phases of the moon. A total of 486 kg of fish coming from 12 different genera, including mollusk and crustaceans, was caught and identified from the catch of the stationary lift net. Among the 12 genera identified from the catch of stationary lift net, anchovy (Stolephorus), sardines (Sardinella), squid (Loligo) and mysid shrimp (Acetes) were considered to be commercially important due to their value. Acetes catch was highest during the new moon in the month of January. Loligo catch was also high during the new moon except in the month of May. Stolephorus catch was also highest during the new moon except in the month of January. Sardinella catch was highest during the first quarter in the month of February. Full moon had the lowest catch all throughout the duration of the study while new moon had the highest catch during December 2013 to March 2014 and first quarter was the highest in the months of April and May.