Modeling Approach for Earthen Dam Breach Analysis in North Yamar Dam, Myanmar

  • Pa Pa Shwe Sin Kyaw Irrigation and Water Utilization Management Department, the Republic of the Union of Myanmar
Keywords: Dam breaks outflow, HEC-RAS, PMF, HEC-HMS, Scenario analysis


In case a Dam breach occurs, it is hazardous for lives, properties and environment in downstream extents. Dam break studies are necessary for forecasting of flood disaster and evaluation of hydrological safety among dams. To investigate possible inundation extents and breach outflow, an experimental study for both overtopping and piping failures was performed in the North Yamar Lower Dam constructed across Yamar creek in Pale township of Sagaing Region. This study is to examine the applicability of hydraulics and hydrologic models, HEC-RAS (USACE Hydrologic Engineering Center’s River Analysis system) and HEC-HMS (Hydrologic Engineering Center’s Hydrologic Modeling System) upon Dam Break. One-dimensional HEC-RAS model was applied in collaboration with HEC-HMS model to predict the potential flood risk due to different breach modes. The extreme hydrological event such as possible maximum flood event (PMF) was considered for the overtopping breach and sunny day piping event for piping breach. Dam Breach outflow hydrographs were generated by HEC-HMS individually and imported them into HEC-RAS for downstream flood estimation. The unsteady mixed flow simulations were performed by HEC-RAS and ArcGIS (Geographic Information System) was used to produce an inundation map based on simulated water surface elevations and extents. The models were calibrated based on the historical floods happened in North Yamar Dam from 2005 to 2017. By scenario analysis for with and without emergency spillway, overtopping breach influenced on different consequences whereas piping affected not much differences. The probable peak discharge would be over 7,000 m3/s and 3,800 m3/s respectively.


. S. Kilania and B. R. Chahar, “A dam break analysis using HeC-RAs,” World Environ. Water Resour. Congr. 2019 Hydraul. Waterw. Water Distrib. Syst. Anal. - Sel. Pap. from World Environ. Water Resour. Congr. 2019, vol. 2011, no. June, pp. 382–389, 2019, doi: 10.4236/jwarp.2011.36047.

. K. Z. Abdulrahman, “Case Study of the Chaq-Chaq Dam Failure : Parameter Estimation and Evaluation of Dam Breach Prediction Models,” Int. J. Eng. Res. Appl., vol. 4, no. 5, pp. 109–116, 2014.

. A. Shahraki, A. Zadbar, M. Motevalli, and F. Aghajani, “Modeling of earth dam break with SMPDBK case study: Bidekan earth dam,” World Appl. Sci. J., vol. 19, no. 3, pp. 376–386, 2012, doi: 10.5829/idosi.wasj.2012.19.03.1070.

. USACE, “Using HEC-RAS for Dam Break Studies,” Us Army Corps Eng. Hydrol. Eng. Cent., no. August, p. 74, 2014.

. DRIP, “Guidelines for Mapping Flood Risks Associated with Dams,” no. January, 2018.

. H. Classifications and D. B. Analysis, “Overtopping Failure Overtopping Breach of Earth Dam,” pp. 1–16, 2006.

. E. K. Forkuo, C. Fosu, and M. Y. Asare, “GIS-based River Inundation and Flood Hazard Mapping,” 2011.

. World Meteorological Organization, Manual for Estimation of Probable Maximum Precipitation, no. 1045. 1986.

. E. Hani and M. S. Shamkhi, “Introduction of Hydrologic Modeling System ( HEC-HMS ) Wasit university College of Engineering Hydrologic Modeling System ( HEC – HMS ) By Eman Hani Hameed Supervised by Assistant Prof . Dr . Mohammed siwan,” no. December, 2018, doi: 10.13140/RG.2.2.35554.58560.

. D. C. Froehlich, “Embankment dam breach parameters and their uncertainties,” J. Hydraul. Eng., 2008, doi: 10.1061/(ASCE)0733-9429(2008)134:12(1708).

. HEC-RAS, “Hydraulic Reference Manual Version 5.0,” no. February, p. 547, 2016.

. V. T. Chow, “Open Channel Hydraulics. Mcgraw-Hill Company,” Erlangga : Bandung., 1959.

. Y. Baba and H. Zhang, “Study on Piping Failure of Natural Dam Ripendra AWAL , Hajime NAKAGAWA , Masaharu FUJITA , Kenji KAWAIKE ,” no. 54, 2011.