Modelling for coastal defence

Climate change and its potential threats have been a key area of research for NUS. To better assess the impact of climate change on Singapore’s coastal areas, a consortium led by NUS has been appointed by national water agency PUB to develop a model capable of evaluating both inland and coastal flood risks in tandem.

Together with water management solutions provider Hydroinformatics Institute (H2i), the NUS researchers led by Professor Philip Liu, Distinguished Professor from NUS Civil and Environmental Engineering, will work on a state-of-the-art Coastal-Inland Flood Model based on the nation’s densely built-up and urbanised environment. PUB officers will work closely with the project team during the entire project duration to share their experience with existing modelling systems.

The purpose-built model will enable holistic flood risk assessment by estimating the combined effects of extreme sea levels and inland floods caused by intense rainfall. It will aid PUB in the planning of coastal adaptation measures, to evaluate the effectiveness of the proposed coastal protection infrastructure, as well as for operations management.

“NUS is excited to be leading this consortium. I am confident that the synergistic pool of talent and resources from NUS, H2i and PUB will catalyse a collaborative advancement of Singapore’s efforts to bolster coastal protection. In anticipating continued climate changes, the development of a national coastal-inland flood model is timely and will help to safeguard both our coastlines and our collective future against severe weather and rising sea levels,” said Prof Liu, who is internationally recognised for his work on coastal engineering and wave modelling.

The modelling system will comprise two independent models – a coastal model and an inland model. The coastal model will be able to simulate potential changes in nearshore waves and storm surge activities within the region under different climate change scenarios, while the inland model will be capable of simulating urban flooding caused by different sources, including heavy rainfall, and its interactions with sea levels. They can be run separately or together to cater for the modelling of different climate scenarios.

Development will take about four years, and advanced modelling techniques will be used to enhance the accuracy and speed in simulating rainfall-induced flows within Singapore’s water catchments. The model will be continually updated and improved along with new climate data and developments in climate science. In the near term, the model will also be able to support the upcoming site-specific studies, starting with the City-East Coast, and Jurong Island.

Industry partner H2i will contribute its rich expertise in hydrological and inland flow modelling and model development.

Singapore has many low-lying areas and is particularly susceptible to rising sea levels. Ms Hazel Khoo, Director of PUB’s Coastal Protection Department, said, “The development of this model is timely as we embark on the monumental task of building coastal defences for Singapore. Through this project, we aim to enhance capabilities and deepen our expertise in modelling to support coastal protection efforts from now and into the future. Given the uncertainties in climate science, protecting our coastlines will always be a work-in-progress, but we aim to stay ahead of the curve. We are pleased to have both NUS and H2i on board and look forward to working with them on this important project.”