Dam breach modeling and downstream flood inundation hazard at Kaeng krachan dam in Phetchaburi province, Thailand | |
| Author | Pantila Ramanandana |
| Call Number | AIT Thesis no.WM-19-19 |
| Subject(s) | Dam failures--Thailand--Kaeng Krachan Dam--Mathematical models Flood control--Thailand--Kaeng Krachan Dam |
| Note | A thesis submitted in partial fulfillment of the requirements for the degree of Master of Engineering in Water Engineering and Management |
| Publisher | Asian Institute of Technology |
| Abstract | This study presents development of dam breach scenarios and prediction of flood inundation hazard downstream of Kaeng Krachan dam. In this study, estimation of inflow to reservoir is done by using HEC-HMS. The model calibration and verification at B.5 station of Phetchaburi river during 2006-2010 and 2014-2018 showed that the coefficient of determination of HEC-HMS model R2 is equal to 0.77 and 0.72, respectively which illustrated very good correlation while, the precision and accuracy of model result, RMSE and NSE remain acceptable. The study considers 2 cases of dam breach scenarios which comprise of overtopping and piping with failure of rectangular breach shapes using Brch-J model. Prediction of flood inundation areas of the Kaeng Krachan dam was studied for the return period of 100, 200, 500 years and probable maximum precipitation (PMP). From the study results, it was found that the collapse feature due to the overtopping failure is more severe than the piping failure. The most excessive impact occurred from the overtopping failure made the water level in the Kaeng Krachan dam rapidly decreased. The flood inundation due to piping is less than that due to overtopping. In comparison of the breach outflow in each scenario, the flooding area at downstream of Kaeng Krachan dam increased not significantly according to the inflow of different return periods. This is because the volume of flood inflow into the reservoir was only a few portion compared to the volume of water storage in the Kaeng Krachan reservoir. For the prediction of flood inundation areas downstream of the dam using HEC-RAS model, the maximum flooded area is from the overtopping scenario caused by the probable maximum precipitation (PMP) that leads to maximum flooding of an area of 1,557 square kilometers. The flood due to dam breach overtopping would take 44 hours 23 minutes after the dam breach from the Kaeng Krachan dam to the Phetchaburi dam. The highest impacted area is at Tha Yang district which are located 30 kilometers from the Kaeng Krachan dam. The study result can be applied to determine flood inundation boundary as a guideline for evacuation planning and management |
| Year | 2019 |
| Type | Thesis |
| School | School of Engineering and Technology (SET) |
| Department | Department of Civil and Infrastucture Engineering (DCIE) |
| Academic Program/FoS | Water Engineering and Management (WM) |
| Chairperson(s) | Tawatchai Tingsanchali;Shrestha, Sangam; |
| Examination Committee(s) | Ekasit Kositsakulchai;Sarawut Ninsawat ; |
| Scholarship Donor(s) | Royal Thai Government Fellowship; |
| Degree | Thesis (M.Eng.) - Asian Institute of Technology, 2019 |