712 / 2024-09-19 10:01:43

Sea Level Rise and Storm Surge projections for design criteria in the Singapore Strait

sea level rise, storm surge predictions, infrastructure design criteria, coastal adaptation

The Singapore Strait is surrounded by significant coastal ports, marina developments, coastal canals, housing estates, transport infrastructure and tourist developments. Planning for the protection of assets and adaptation to the threat of sea level rise is considering major protection developments such as outer sea dikes, reclamation areas, tidal gate barrages, pump stations and coastal reservoirs to augment water supply. The design of this protection infrastructure requires sound projections of sea level rise and extreme storm surge events to support the engineering design process and ongoing operations planning. Singapore Strait is a macro-tidal zone with spring tide range of 3.5 m and strong spring-neap cycle and annual oscillation with highest springs November to February and storm surges propagating westward from the South China Sea into the Strait. 38 years of historic sea level records at Tanjong Pagar on the south coast of Singapore and ERA winds in the South China Sea north of Kalimantan and south of Vietnam are analysed to highlight the key physical processes influencing the extreme storm surge events over this period. The sea level record was decomposed into the predicted tide, low-pass tidal residuals – the storm surge- and skew surge tide. The Tanjong Pagar storm surge is shown to be well correlated to the winds off Kalimantan and weaker but importantly lagged correlation with winds south of Vietnam. A simple predictive tool relating the storm surge to the winds off Kalimantan is able to capture the higher storm surge events variance. Extreme value analysis is used to provide likely future storm surge amplitudes for use in the design of coastal infrastructure, its future operation and tipping points. This presentation will focus on the key learnings to support better understanding of sea levels, past and future projections, and its application in coastal zone adaptation planning for coastal communities in the Singapore Strait.