Developing a coastal flood forecasting model: Enhancing early warning of natural disasters.

The Ministry of Science and Technology has just evaluated and approved the national-level science and technology project "Research on building a model and technological process for forecasting coastal flooding caused by storm surges and waves." After nearly three years of implementation with a wide survey scope, the research team has developed a detailed coastal flooding forecasting model, opening up avenues for improving early warning and supporting disaster response.

Coastal flooding is becoming increasingly severe.

Coastal flooding is a common natural disaster that occurs during storms and causes significant damage to people, property, and the environment. Many storms around the world have caused flooding and devastation in coastal areas, such as Hurricane Katrina (2005) in the US, Typhoon Sidr (2007), Typhoon Haiyan (2013) in the Philippines, and Typhoon Amphan (2020) in India and Bangladesh. In Vietnam, several strong storms such as Damrey (2005), Xangsane (2006), and Doksuri (2017) have caused severe flooding in coastal areas due to rising sea levels.

In 2025 alone, the East Sea recorded 14 typhoons, many of which were strong and made direct landfall in Vietnam, causing severe flooding and heavy damage in many provinces and cities: Kajiki (typhoon No. 5, late August) and Bualoi (typhoon No. 10, late September) made landfall in Nghe An and Ha Tinh; Matmo (typhoon No. 11, late October) caused heavy rain and floods in Thai Nguyen, Lang Son, and Bac Ninh ; Kalmaegi (typhoon No. 13, early November) affected the coastal areas of Gia Lai and Dak Lak. These typhoons not only brought strong winds and heavy rain, but also caused storm surges and large waves that sank ships, destroyed aquaculture farms, caused deep flooding and coastal erosion, threatening the livelihoods of millions of coastal residents.

In recent years, research on coastal flooding has made significant progress thanks to a better understanding of the causes and mechanisms of flooding, as well as advancements in theory and computational capabilities. However, research on storm surge flooding still faces gaps in practical application. The main reasons are limited understanding of the interactions between factors causing storm surge, the need to simplify many processes, and the current computational capabilities not yet meeting the requirements for detailed spatial simulation.

In this context, the development of a highly accurate coastal flood forecasting model is an urgent requirement. As part of a national-level science and technology task, the National Center for Meteorological and Hydrological Forecasting has implemented the project "Developing a model and technological process for forecasting coastal flooding caused by storm surges and waves," carried out from December 2022 to November 2025, led by Associate Professor Dr. Nguyen Ba Thuy.

Develop a national-scale early warning system.

To date, the research team has completed the collection and processing of meteorological, hydrological, oceanographic, and topographic data for simulation purposes. Advanced models such as WRF (weather forecasting model), SWAN (wave model), and ADCIRC (storm surge calculation model) have been integrated to simulate storm winds, waves, and storm surges, thereby forming a comprehensive flood forecasting system for coastal areas. The model has been tested in the coastal area of ​​Thanh Hoa province with a detailed map scale of 1/10,000, helping to assess flood scenarios caused by storms and tidal surges under various conditions.

Specifically, the research team developed a set of coastal flood maps for Thanh Hoa province based on storm levels 11 to 14, incorporating scenarios of storm landfall during high tide. These products have been transferred to forecasters and local authorities, enabling them to be more proactive in planning for evacuation, protecting boats, tourism infrastructure, and dike systems.

One of the project's outstanding contributions is the development of a separate flood forecasting process for two types of terrain: areas with sea dikes and areas without dikes. Differences in elevation, protective capacity, and coastal structure require a corresponding forecasting approach to ensure effective early warning. The toolkit has been tested during the 2025 typhoon season and has shown a high degree of correlation with reality.

Associate Professor Dr. Nguyen Ba Thuy, on behalf of the research team, presented the topic on building a model for predicting coastal flooding.

Mr. Hoang Duc Cuong, Deputy Director of the Department of Meteorology and Hydrology (Ministry of Agriculture and Environment), assessed that the project has closely followed its objectives and completed important products, contributing to improving the quality of early warning for coastal areas.

According to Associate Professor Dr. Nguyen Ba Thuy, the model not only has scientific significance but also helps raise awareness among forecasters about the combined impact of sea level rise, large waves, and storms – factors that can cause severe flooding even when the storm's center does not make a direct landfall. Associate Professor Dr. Nguyen Ba Thuy believes that a sufficiently powerful computing system is needed to operate the model in real time, in order to serve forecasting purposes.

Experts believe that the coastal flood forecasting model can be fully replicated for many coastal provinces and cities – areas frequently facing high tides and strong storms. This tool will support crucial decision-making in disaster prevention, coastal urban planning, and coastal economic development.

Based on these initial results, the meteorological and hydrological sector is gradually developing high-tech forecasting capabilities, contributing to protecting communities from extreme weather events and promoting sustainable development of the marine economy in the future.

TRAN LUU - DINH BACH

Source: https://www.sggp.org.vn/xay-dung-mo-hinh-du-bao-ngap-lut-ven-bien-nang-cao-canh-bao-som-thien-tai-post828016.html