1421 / 2024-09-27 00:07:46

Evaluating The Combined Threats of Sea Level Rise, Storm Surge and Surface Waves over the Coastal Areas in Malaysia

sea level rise, costal inundation, extreme wave, storm surge, climate change

Session 23 - Sea level rise: understanding, observing, and modelling

Over the last 100-years, global mean sea level has risen with an average rate of ~1.7mm/year and the rate of rising has accelerated to 3.2-3.7 mm/year over the last 20-30 years. Both gauges and satellite altimetry data over Malaysia's coastal regions indicate a slightly higher regional mean sea level rise rate of 3.5–4.5 mm/year. As the world continues to warm due to anthropogenic activities, the mean sea level is expected to rise further in coming decades. The magnitude of the rise would depend on how warm the Earth could get in the future, presumably depending how well our society mitigate the emission of greenhouse gases.  The impact of mean sea level rise can be compounded by changing storm surge due to changing low level atmospheric circulation and also tidal characteristics as well as the extreme surface wind wave. This overall altering the risk of inundation at the coastal regions over Malaysia. This is expected to threaten Malaysia's coastal communities, putting lives, livelihoods, and infrastructure a risk. Therefore, a comprehensive risk assessment taking into account the inundation due to combined effect of mean sea level rise, extreme storm surge and tide as well as the wind waves is required. In this presentation, a simple assessment framework for coastal inundation risk are introduced. This framework takes into account the IPCC AR6 regional sea level projections, extreme analysis from a global storm surge and tide model as well as our national wave hindcast. Finally, the implication of sea level rise to the inundation over Malaysia areas will be discussed.