TY - JOUR
T1 - Complex extreme sea levels prediction analysis
T2 - Karachi coast case study
AU - Khan, Faisal Ahmed
AU - Ali Khan, Tariq Masood
AU - Ahmed, Ali Najah
AU - Afan, Haitham Abdulmohsin
AU - Sherif, Mohsen
AU - Sefelnasr, Ahmed
AU - El-Shafie, Ahmed
N1 - Funding Information:
This research was funded by University of Malaya Research Grant (UMRG) coded RP025A-18SUS University of Malaya, Malaysia. The authors wish to express their gratitude to Philip L. Woodworth, National Oceanography Centre, Liverpool, UK for his guidance and useful comments. We also thank the Karachi Port Trust for providing the sea level data of Karachi Port. The research quality data were obtained from the University of Hawaii Sea Level Center data archive. The authors would like to appreciate so much the financial support received from the University of Malaya Research Grant (UMRG) coded RP025A-18SUS University of Malaya, Malaysia.
Funding Information:
Funding: This research was funded by University of Malaya Research Grant (UMRG) coded RP025A-18SUS University of Malaya, Malaysia.
Publisher Copyright:
© 2020 by the authors.
PY - 2020/5/1
Y1 - 2020/5/1
N2 - In this study, the analysis of the extreme sea level was carried out by using 10 years (2007-2016) of hourly tide gauge data of Karachi port station along the Pakistan coast. Observations revealed that the magnitudes of the tides usually exceeded the storm surges at this station. The main observation for this duration and the subsequent analysis showed that in June 2007 a tropical Cyclone "Yemyin" hit the Pakistan coast. The joint probability method (JPM) and the annual maximum method (AMM) were used for statistical analysis to find out the return periods of different extreme sea levels. According to the achieved results, the AMM and JPM methods erre compatible with each other for the Karachi coast and remained well within the range of 95% confidence. For the JPM method, the highest astronomical tide (HAT) of the Karachi coast was considered as the threshold and the sea levels above it were considered extreme sea levels. The 10 annual observed sea level maxima, in the recent past, showed an increasing trend for extreme sea levels. In the study period, the increment rates of 3.6 mm/year and 2.1 mm/year were observed for mean sea level and extreme sea level, respectively, along the Karachi coast. Tidal analysis, for the Karachi tide gauge data, showed less dependency of the extreme sea levels on the non-tidal residuals. By applying the Merrifield criteria of mean annual maximum water level ratio, it was found that the Karachi coast was tidally dominated and the non-tidal residual contribution was just 10%. The examination of the highest water level event (13 June 2014) during the study period, further favored the tidal dominance as compared to the non-tidal component along the Karachi coast.
AB - In this study, the analysis of the extreme sea level was carried out by using 10 years (2007-2016) of hourly tide gauge data of Karachi port station along the Pakistan coast. Observations revealed that the magnitudes of the tides usually exceeded the storm surges at this station. The main observation for this duration and the subsequent analysis showed that in June 2007 a tropical Cyclone "Yemyin" hit the Pakistan coast. The joint probability method (JPM) and the annual maximum method (AMM) were used for statistical analysis to find out the return periods of different extreme sea levels. According to the achieved results, the AMM and JPM methods erre compatible with each other for the Karachi coast and remained well within the range of 95% confidence. For the JPM method, the highest astronomical tide (HAT) of the Karachi coast was considered as the threshold and the sea levels above it were considered extreme sea levels. The 10 annual observed sea level maxima, in the recent past, showed an increasing trend for extreme sea levels. In the study period, the increment rates of 3.6 mm/year and 2.1 mm/year were observed for mean sea level and extreme sea level, respectively, along the Karachi coast. Tidal analysis, for the Karachi tide gauge data, showed less dependency of the extreme sea levels on the non-tidal residuals. By applying the Merrifield criteria of mean annual maximum water level ratio, it was found that the Karachi coast was tidally dominated and the non-tidal residual contribution was just 10%. The examination of the highest water level event (13 June 2014) during the study period, further favored the tidal dominance as compared to the non-tidal component along the Karachi coast.
KW - Annual maximum method
KW - Complex system prediction
KW - Extreme sea level prediction
KW - Joint probability method
KW - Pakistan coast
UR - http://www.scopus.com/inward/record.url?scp=85085688826&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85085688826&partnerID=8YFLogxK
U2 - 10.3390/E22050549
DO - 10.3390/E22050549
M3 - Article
AN - SCOPUS:85085688826
SN - 1099-4300
VL - 22
JO - Entropy
JF - Entropy
IS - 5
M1 - 549
ER -