The Bago River Basin in Myanmar is highly flood-prone. To develop a flood forecasting system, an inundation map of the Bago River Basin is required. This study applied the Rainfall-Runoff-Inundation (RRI) model and SOBEK model to simulate flood discharges and inundation to determine the model most suitable for analysis of the study basin in terms of user friendliness, cost, type of output, and correlation between simulated and observed data. In this study, five flood events were selected to calibrate and validate the models, using discharge data measured at Bago station. The Nash–Sutcliffe efficiency (E_NS) and coefficient of determination (R²) were used to evaluate the performance of the models. The simulated flood inundation area was validated with satellite images. According to the comparison, the SOBEK model is more accurate than the RRI model, and the simulated and observed discharges are closely related. However, when the calculation time and cost are included in the consideration, the RRI model is preferable, as it is faster and freely available. For the Bago River Basin, the RRI model is efficient in predicting the potential flood duration and areas of inundation in near-real time, whereas the SOBEK model is useful for floodplain management. This study shows that the RRI and SOBEK models are applicable to any basin in Myanmar that is similar to the Bago River Basin.

1. [1] I. M. Muhammal and A. Fahad, “Flood Inundation Mapping and Risk Zoning of the Swat River Pakistan Using HEC-RAS Model,” Lasbela University J. of Science, Vol.3, pp. 45-52, 2014.
2. [2] Myanmar Information Management Unit (MIMU), https://themimu.info/emergencies/monsoon-flooding [accessed July 15, 2019]
3. [3] Department of Metherology and Hydrogy (Myanmar), https://www.moezala.gov.mm/content/flood [accessed July 15, 2019]
4. [4] A. M. Khaing, “Mapping Flood Inundation in the Bago River Basin, Myanmar,” M.Sc. Thesis, Asian Institute of Technology (AIT), 2014.
5. [5] M. Abdel-Fattah, S. A. Kantoush, M. Saber, and T. Sumi, “Hydrological Modelling of Flash Flood at Wadi Samail, Oman,” Annuals of Disas. Prev. Res. Inst., Kyoto Univ., No.59, pp. 533-541, 2016.
6. [6] M. R. Edna, “Floodplain Inundation Simulation Using 2D Hydrodynamic Modelling Approach,” M.Sc. Thesis, International Institute for Geo-Information Science and Earth Observation Enschede, 2007.
7. [7] K. Pakoksung, “Runoff Analysis using Satellite Data for Flood Reginal Assessment,” Dr.Eng. Thesis, Graduate School of Engineering, Kochi University of Technology, 2016.
8. [8] W. W. Zin, A. Kawasaki, and S. Win, “River Flood Inundation Mapping in the Bago River Basin, Myanmar,” Hydrological Research Letters, Vol.9, No.4, pp. 97-102, 2015.
9. [9] W. W. Zin, A. Kawasaki, W. Takeuchi, Z. M. L. T. San, K. Z. Htun, T. H. Aye, and S. Win, “Flood Hazard Assessment of Bago River Basin, Myanmar,” J. Disaster Res., Vol.13, No.1, pp. 14-21, 2018.
10. [10] S. Win, W. W. Zin, A. Kawasaki, and Z. M. L. T. San, “Establishment of Flood Damage Function Models: A Case Study in the Bago River Basin, Myanmar,” Int. J. of Disaster Risk Reduction, Vol.28, pp. 688-700, 2018.
11. [11] S. S. Bhagabati and A. Kawasaki, “Consideration of the Rainfall-Runoff Inundation (RRI) Model for Flood Mapping in Deltaic Area of Myanmar,” Hydrological Research Letters, Vol.11, No.3, pp. 155-160, 2017.
12. [12] R. A. Acierto, A. Kawasaki, W. W. Zin, A. T. Oo, K. Ra, and D. Komori, “Development of a Hydrological Telemetry System in Bago River,” J. Disaster Res., Vol.13, No.1, pp. 116-124, 2018.
13. [13] T. Sayama, Y. Tatebe, Y. Iwami, and S. Tanaka, “Hydrologic Sensitivy of Flood Runoff and Inundation: 2011 Thailand Floods in the Chao Phraya River Basin,” Nat. Hazards Earth Syst. Sci., Vol.15, pp. 1617-1630, 2015.
14. [14] T. Sayama, G. Ozawa, T. Kawakami, S. Nabesaka, and K. Fukami, “Rainfall-Runoff-Inundation Analysis of the 2010 Pakistan Flood in the Kabul River Basin,” Hydrological Science J., Vol.57, pp. 298-312, 2012.
15. [15] Deltares, “SOBEK, Hydrodynamic, Rainfall Runoff and Real Time Control,” 2016.
16. [16] A. Sanchez, “Development of a Computer Based 1D-2D Dynamic Flood Model, Case Study of the Pagsangaan River Basin in Leyte, the Phillippines,” M.Sc. Thesis, Technische Universität München, 2011.
17. [17] S. S. Bhagabati, “Development of a Near-Real Time Flood Inundation Analysis System for a Deltaic Flat River Basin in a Data-Scarce Region; Case of the Bago River basin, Myanmar,” Ph.D. Thesis, Department of Civil Engineering, School of Engineering, The University of Tokyo, 2018.
18. [18] S. Win, “Development of Flood Inundation Map for the Bago River,” M.Eng. Thesis, Department of Civil Engineering, Yangon Technological University, 2014.