Validation of existing debris flow models using road no. 1081 km. 90 data in Northern, Thailand | |
| Author | Nussarin Sudrohman |
| Call Number | AIT Thesis no.GE-20-05 |
| Subject(s) | Debris avalanches--Control--Thailand (Northern) Digital elevation models--Thailand (Northern) |
| Note | A thesis submitted in partial fulfillment of the requirements for the degree of Master of Engineering in Geotechnical and Earth Resources Engineering |
| Publisher | Asian Institute of Technology |
| Abstract | The debris flow at road no. 1081 km 90+900 that occurred during SON-TINH storm in 2018 was used to validate the existing debris flow models, including DFLOWZ and Debris-2D. The total debris flow volume was estimated from Digital Elevation Model (DEM) analysis and TRIGRS model by considering the instability depth (FS≤1) for potential debris flow analysis. The results reveal that the volume from DEM analysis and TRIGRS model are 7863.43 and 9672.97 m3, respectively, and the volume from the TRIGRS model is shown with 23% difference compared to the DEM analysis result. The actual deposition and affected areas were depicted from aerial photos used to validate simulated deposition areas. Combining the DEM and DFLOWZ model provides good agreement results with 16% and 34% difference in deposition area and overlap deposition area. The combining TRIGRS and DFLOWZ model also simulates deposition area with 28% difference to the actual deposition area, and the simulated deposition area overlaps with the actual deposition area about 76%. For Debris-2D, the yield stress is the most critical controlling parameter and was performed a sensitivity analysis. At lower yield stress, the debris flows further downstream. On the other hand, the higher yield stress debris early terminates and deposit before the field observation flow front. The minimum yield stresses causing the simulation termination or the debris deposits for the combining DEM and Debris-2D, and the combining TRIGRS and Debris-2D are 8000 and 9500 Pa, respectively. At a yield stress level, the combining DEM and Debris-2D simulate the debris to terminate before the actual flow front. In contrast, the combining TRIGRS and Debris-2D show the debris to flow over the actual deposition area and take a longer time to deposit. As a result, both combining DEM or TRIGRS and Debris-2D provide about 25-52% overestimated affected area depending on yield stress and flow volume. |
| Year | 2021 |
| Type | Thesis |
| School | School of Engineering and Technology (SET) |
| Department | Department of Civil and Infrastucture Engineering (DCIE) |
| Academic Program/FoS | Geotechnical Engineering (GE) |
| Chairperson(s) | Chao, Kuo Chieh; |
| Examination Committee(s) | Avirut Putiwongrak; |
| Scholarship Donor(s) | His Majesty the King's Scholarships (Thailand); |
| Degree | Thesis (M. Eng.) - Asian Institute of Technology, 2021 |