Tidal Harmonic Analysis and Prediction to Support Early Warning for Coastal Flooding
Randi Firdaus (a*), Nurul Tazaroh (a), Oky Surendra (a), Eko Prasetyo (a), Riris Adriyanto (a)

a) Center for Marine Meteorology, Indonesian Agency for Meteorology Climatology and Geophysics (BMKG)
Jalan Angkasa 1, No.2, Jakarta 10610, Indonesia
*randi.firdaus[at]bmkg.go.id

Abstract

Indonesian Maritime Continent (IMC) is the largest archipelago that vulnerable to climate change especially sea level rise. Some coastal area frequently experiences the coastal flooding affecting the activities and infrastructures in the coastal area. Thus, an accurate tide prediction in this region has a pivotal role in order to provide the early warning, mitigation, and adaptation to frequent coastal flooding. BMKG through the Center for Marine Meteorology that mandate to provide the tidal information has done some effort to provide an accurate tidal prediction information through developing the tidal information system call INATIS (Indonesian Tidal Information System). The tidal harmonic analysis (THA) using the least-square method was applied to sea level data from 49 Marine Automatic Weather System (MAWS) stations for the period 2020-2022 to generate tidal predictions for the period 2022-2023. Tidal accuracy was assessed based on Mean Absolute Error (MAE) and the Mean Absolute Percentage Error (MAPE). MAWS stations with prediction accuracy above 80% were visualized on the online platform using the open-source Looker Studio, accessible to the public at https://maritim.bmkg.go.id/tide. The tidal predictions verification showed an average prediction accuracy of 93.21% with MAE of 0.114 m. The high accuracy of INATIS demonstrates its potential as a reference for coastal flood early warning systems.

Keywords: tidal prediction, tidal harmonic, coastal inundation, looker studio

Topic: Operational Oceanography