ANALYSIS OF TIDES IN SINGAPORE WATERS

Abstract

This research aims to conduct a statistical analysis on the tidal elevations at 4 selected tidal stations, namely Jurong Wharf; Raffles Lighthouse, Angler Bank and Tanjong Pagar Terminal to establish the trends in the variation of mean sea level (MSL) around Singapore waters. The various causes of sea level fluctuations are investigated and studied. The monthly and yearly MSLs are computed and 't' statistical test conducted to verify the significance of the MSL variation. From 1984 to 1992, there is an average annual decline in MSL between 0.017 cm at Jurong to 0.35 cm at Angler Bank. However, the apparent downward trend is found to be significant. On the other band, there is a significant annual decrease in the monthly Lowest Low Water (LLW) at Jurong Wharf and Raffles Lighthouse of 0.45 cm and 0.63 cm respectively. Subsequently, time series analysis is carried out to develop ARIMA models for the monthly MSL at Jurong Wharf and monthly Highest High Water (HHW) at Raffles Lighthouse. The predicted values an verified to compare favourably with the actual field data with rms errors ranging from 0. 7 % to 3 %. Investigation of seasonal MSL variation reveals that the meteorological effect of monsoonal wind field is predominant. The monthly variations in sea levels are between -6cm and 12 cm relative to MSL at Raffles Lighthouse and Jurong Wharf; whilst the variations at Tanjong Pagar Terminal and Angler Bank range from -10 cm to 18 cm relative to MSL.