Observations and Numerical Simulation of Storm Surge during Typhoon Kajiki (August 2025)
Main Article Content
Abstract
In this study, the storm surge associated with Typhoon No. 5 (Kajiki, August 2025) was analyzed using both observational data and numerical model simulations. Observational data from the Hon Ngu and Hon Dau oceanographic stations were selected for analysis. The simulations were conducted using the SuWAT model, an integrated numerical system that couples tides, wind waves, and storm surge processes. The results indicate that at the Hon Ngu station, the observed water level reached 3.99 m, with a maximum storm surge of 2.31 m - the highest value recorded over the past 30 years. At the Hon Dau station, although located far from the typhoon center, the maximum storm surge still reached 0.63 m. The maximum surge at Hon Ngu occurred when the typhoon center was approximately 80 km offshore, whereas at Hon Dau it happened when the typhoon center had moved about 50 km inland. At Hon Ngu, the surge induced solely by atmospheric pressure reduction was approximately 0.5 m; however, it occurred after the peak total surge.
Keywords:
Kajiki typhoon; Storm surges; SWAT model; Hon Ngu.
References
[1] https://www.nps.gov/guis/learn/historyculture/hurricane-.katrina.htm#:~:text=Winds%20of%20up %20to%20120,%2D%2030%20feet)%20in%20height (accessed on: July 10th, 2025).
[2] P. V. Tien, N. B. Thuy, S. Kim, N. K. Cuong, P. K. Ngoc, M. V. Khiem, L. H. Hole, Impact of the Interaction of Surge, Wave, and Tide on the Surge and Wave on the Northern Coast of Vietnam for A Marine Storm Surge and Wave Forecast System, Reg. Stud. Mar. Sci., Vol. 87, 2025, pp. 104234.
[3] Meteorological and Hydrological Characteristics in 2024, National Center for Hydro-meteorological Forecasting, 2025 (in Vietnamese).
[4] Meteorological and Hydrological Characteristics in 2020, National Center for Hydro-meteorological Forecasting, 2021 (in Vietnamese).
[5] P. T. Thuc, Study on the Characteristics of Storm Surge and Monsoon-Induced Water Level Rise in the Coastal Waters of the Gulf of Tonkin. Phd Dissertation, University of Science, Vietnam National University, Hanoi, 2021 (in Vietnamese).
[6] N. B. Thuy, S. Kim, T. N. Anh, N. K. Cuong, P. T. Thuc, L. H. Hole, The Influence Moving Speeds, Wind Speeds, and Sea Level Pressures on After-Runner Storm Surges in the Gulf of Tonkin, Vietnam, Ocean Eng, Vol. 212, 2020, pp. 107613.
[7] Y. Funakoshi, S. C. Hagen, P. Bacopoulos, Coupling of Hydrodynamic and Wave Models: Case Study for Hurricane Floyd (1999) Hindcast, J. Waterw. Port Coast. Ocean Eng., Vol. 134, 2008, pp. 321-335.
[8] S. Y. Kim, T. Yasuda, H. Mase, Storm Surge Simulations Occurred in Tosa Bay by Using Surge-wave-tide Coupled Model, Annual Journal of Coastal Engineering, JSCE, Vol. 55, 2008,
pp. 321-325.
[9] S. Y. Kim, T. Yasuda, H. Mase, Wave Set-up in the Storm Surge Along Open Coasts During Typhoon Anita, Coast. Eng., ASCE, Vol. 57, 2010, pp. 631-642.
[10] Q. Chen, L. Wang, H. Zhao, An Integrated Surge and Wave Modeling System for Northern Gulf of Mexico: Simulations for Hurricanes Katrina and Ivan. Proceedings of the 31st International Conference on Coastal Engineering (Hamburg, Germany), Vol. 2, 2008, pp. 1072-1084.
[11] N. B. Thuy, H. D. Cuong, D. D. Tien, D. D. Chien, S. Kim, Assessment of Storm Surge Evolution Caused by Typhoon and Related Forecasting Issues, Journal of Hydro-Meteorology, Vol. 647, No. 3, 2014 (in Vietnamese).
[12] N. N. Thuy, Study on the Mechanism of Post-Landfall Storm Surge Along the Northern Vietnam Coast, Vietnam Journal of Marine Science and Technology, Vol. 17, No. 4B, 2017, pp. 208-216.
[13] N. B. Thuy, S. Kim, V. H. Dang, H. D. Cuong, C. Wettre, L. R. Hole, Assessment of Storm Surge Along the Coast of Central Vietnam. J. Coastal Res., Vol. 33, 2017, pp. 518-530.
[14] D. D. Chien, N. B. Thuy, N. T. Sao, T. H. Thai,
S. Kim, Study on the Interaction Between Waves and Storm Surge Using a Numerical Model, Journal of Hydro-Meteorology, Vol. 647, 2014
(in Vietnamese).
[15] V. H. Dang, N. B. Thuy, D. D. Chien, S. Kim, Study on the Quantitative Assessment of Storm Surge Components Using A Numerical Model, Vietnam Journal of Marine Science and Technology, Vol. 17, No. 2, 2017, pp. 132-138
(in Vietnamese).
[16] P. K. Ngoc, N. T. Luan, N. B. Thuy, S. Kim, V. H. Dang, The Impact of Wave on Coastal Inundation. Proc., of the 8th Asia-Pacific Workshop on Marine Hydrodynamics in Nava Architecture, Ocean Technology and Contractions, 2016, pp. 168-173.
[17] Report on the Development of Typhoon No. 5 (Kajiki), Heavy Rainfall, Floods, Flash Floods, Landslides, and Forecasting Activities, National Center for Hydro-Meteorological Forecasting, September 2025 (in Vietnamese).
[18] https://baonghean.vn/hinh-anh-cua-lo-chieu-25-8-bien-dong-du-doi-nhieu-tuyen-duong-ven-bien-ngap-do-bao-so-5-10305203.html (accessed on: July 10th, 2025).
[19] https://www.vietnamplus.vn/thanh-hoa-anh-huong-bao-so-5-bien-sam-son-song-lon-thuy-trieu-tran-qua-de-post1057839.vnp#google_vignette (accessed on: July 10th, 2025)
[20] Report on the Results of Coastal Flooding Survey After Typhoon No. 5, National Center for Hydro-Meteorological Forecasting, August 2025 (in Vietnamese).
[21] P. A. E. M. Janssen, Quasi-Linear Theory of Wind-wave Generation Applied to Wave Forecasting, J. Phys. Oceanogr., Vol. 21, 1991, pp. 1631-164.
[2] P. V. Tien, N. B. Thuy, S. Kim, N. K. Cuong, P. K. Ngoc, M. V. Khiem, L. H. Hole, Impact of the Interaction of Surge, Wave, and Tide on the Surge and Wave on the Northern Coast of Vietnam for A Marine Storm Surge and Wave Forecast System, Reg. Stud. Mar. Sci., Vol. 87, 2025, pp. 104234.
[3] Meteorological and Hydrological Characteristics in 2024, National Center for Hydro-meteorological Forecasting, 2025 (in Vietnamese).
[4] Meteorological and Hydrological Characteristics in 2020, National Center for Hydro-meteorological Forecasting, 2021 (in Vietnamese).
[5] P. T. Thuc, Study on the Characteristics of Storm Surge and Monsoon-Induced Water Level Rise in the Coastal Waters of the Gulf of Tonkin. Phd Dissertation, University of Science, Vietnam National University, Hanoi, 2021 (in Vietnamese).
[6] N. B. Thuy, S. Kim, T. N. Anh, N. K. Cuong, P. T. Thuc, L. H. Hole, The Influence Moving Speeds, Wind Speeds, and Sea Level Pressures on After-Runner Storm Surges in the Gulf of Tonkin, Vietnam, Ocean Eng, Vol. 212, 2020, pp. 107613.
[7] Y. Funakoshi, S. C. Hagen, P. Bacopoulos, Coupling of Hydrodynamic and Wave Models: Case Study for Hurricane Floyd (1999) Hindcast, J. Waterw. Port Coast. Ocean Eng., Vol. 134, 2008, pp. 321-335.
[8] S. Y. Kim, T. Yasuda, H. Mase, Storm Surge Simulations Occurred in Tosa Bay by Using Surge-wave-tide Coupled Model, Annual Journal of Coastal Engineering, JSCE, Vol. 55, 2008,
pp. 321-325.
[9] S. Y. Kim, T. Yasuda, H. Mase, Wave Set-up in the Storm Surge Along Open Coasts During Typhoon Anita, Coast. Eng., ASCE, Vol. 57, 2010, pp. 631-642.
[10] Q. Chen, L. Wang, H. Zhao, An Integrated Surge and Wave Modeling System for Northern Gulf of Mexico: Simulations for Hurricanes Katrina and Ivan. Proceedings of the 31st International Conference on Coastal Engineering (Hamburg, Germany), Vol. 2, 2008, pp. 1072-1084.
[11] N. B. Thuy, H. D. Cuong, D. D. Tien, D. D. Chien, S. Kim, Assessment of Storm Surge Evolution Caused by Typhoon and Related Forecasting Issues, Journal of Hydro-Meteorology, Vol. 647, No. 3, 2014 (in Vietnamese).
[12] N. N. Thuy, Study on the Mechanism of Post-Landfall Storm Surge Along the Northern Vietnam Coast, Vietnam Journal of Marine Science and Technology, Vol. 17, No. 4B, 2017, pp. 208-216.
[13] N. B. Thuy, S. Kim, V. H. Dang, H. D. Cuong, C. Wettre, L. R. Hole, Assessment of Storm Surge Along the Coast of Central Vietnam. J. Coastal Res., Vol. 33, 2017, pp. 518-530.
[14] D. D. Chien, N. B. Thuy, N. T. Sao, T. H. Thai,
S. Kim, Study on the Interaction Between Waves and Storm Surge Using a Numerical Model, Journal of Hydro-Meteorology, Vol. 647, 2014
(in Vietnamese).
[15] V. H. Dang, N. B. Thuy, D. D. Chien, S. Kim, Study on the Quantitative Assessment of Storm Surge Components Using A Numerical Model, Vietnam Journal of Marine Science and Technology, Vol. 17, No. 2, 2017, pp. 132-138
(in Vietnamese).
[16] P. K. Ngoc, N. T. Luan, N. B. Thuy, S. Kim, V. H. Dang, The Impact of Wave on Coastal Inundation. Proc., of the 8th Asia-Pacific Workshop on Marine Hydrodynamics in Nava Architecture, Ocean Technology and Contractions, 2016, pp. 168-173.
[17] Report on the Development of Typhoon No. 5 (Kajiki), Heavy Rainfall, Floods, Flash Floods, Landslides, and Forecasting Activities, National Center for Hydro-Meteorological Forecasting, September 2025 (in Vietnamese).
[18] https://baonghean.vn/hinh-anh-cua-lo-chieu-25-8-bien-dong-du-doi-nhieu-tuyen-duong-ven-bien-ngap-do-bao-so-5-10305203.html (accessed on: July 10th, 2025).
[19] https://www.vietnamplus.vn/thanh-hoa-anh-huong-bao-so-5-bien-sam-son-song-lon-thuy-trieu-tran-qua-de-post1057839.vnp#google_vignette (accessed on: July 10th, 2025)
[20] Report on the Results of Coastal Flooding Survey After Typhoon No. 5, National Center for Hydro-Meteorological Forecasting, August 2025 (in Vietnamese).
[21] P. A. E. M. Janssen, Quasi-Linear Theory of Wind-wave Generation Applied to Wave Forecasting, J. Phys. Oceanogr., Vol. 21, 1991, pp. 1631-164.