Assessment of spatial and temporal varied pluvial flood hazard due to climate change and storm surge for the coastal city: a case study of Pattaya city – Thailand | |
| Author | Chahe, Gidion Thobias |
| Call Number | AIT Thesis no.UWEM-19-01 |
| Subject(s) | Flood control--Thailand--Pattaya Climatic changes--Thailand--Pattaya Floods--Thailand--Pattaya |
| Note | A thesis submitted in partial fulfilment of the requirements for the degree of Master of Science in Urban Water Engineering and Management Jointly offered by Asian Institute of Technology, Thailand and UNESCO - IHE, Delft, the Netherlands |
| Publisher | Asian Institute of Technology |
| Abstract | Urban areas are prone to flood inundation as a result of a compromised water cycle due to massive land cover change from open field to paved surfaces. Runoff generated has increased at large, conventional infrastructure that is drainage system in place can no longer shield the settlement from flooding. Pluvial flooding is typical kind of flooding describing this inadequacy of stormwater drainage. Despite the fact that urban flooding is becoming a chronic problem yet climate change impacts are making the future become worse than the current situation. The influences on rainfall patterns, intensity and duration along with extreme sea levels pose a great threat to the stormwater drainage system by affecting drainage characteristics and capacity. Discussing potential flood impacts can mainstream the safe handling of the risk prior to the disaster. All stakeholders can join hands when the flood risk is well analysed and communicated, although the trading of potential flood damage and the level of investments to safeguard a certain magnitude of the flood is always complex. From this study, a 1D2D model used to simulate future flood extent in the one-day event for the projected 2years, 5 years and 25 years rainfall intensities combined with sea level rise and 10 years storm surge by the year 2050. After analysis of the potential economic impacts, daily direct damage to the buildings estimated at 9.1M THB, 19.6M THB and 34.1M THB respectively, adding to that indirect damages estimated at 1.1M THB, 1.89M THB and 2.19M THB respectively. To counter the damage caused by resulted pluvial flood, different mitigation approaches were tested against 5 years rain and elevated sea levels superimposed with 10 years storm surge. These approaches included doubling pipe size to enhance drainage capacity, employing 4000m3 detention ponds for increasing storage capacity, lowering runoff coefficient to 50% and a combination of three measures in a suggested proportion. The lowering of runoff to 50% outscored the rest by reducing the initial damage by 7.6M THB, the combination of the measures comes the second by saving 4.5M THB despite a reduction of coefficient of runoff by only 20%, applying 2000m3 detention volume and increasing the pipe size by 20%. To assess the effectiveness of flood mitigation measures against the expense involved is considered to be an iterative process, therefore, all possible options and the combinations have to be considered. Then the refined measures and adaptation strategy can be drawn to meet both short term and long term flood impacts mitigation targets. |
| Year | 2019 |
| Type | Thesis |
| School | School of Environment, Resources, and Development (SERD) + School of Engineering and Technology (SET) |
| Department | Department of Energy and Climate Change (Former title: Department of Energy, Environment, and Climate Change (DEECC)) |
| Academic Program/FoS | Urban Water Engineering and Management (UWEM) |
| Chairperson(s) | Xue, Wenchao;Ranasinghe, Roshanka; |
| Examination Committee(s) | Chettiyappan Visvanathan;Torres, Arlex Sanchez;Sutat Weesakul;Vojinovic, Zoran; |
| Scholarship Donor(s) | Netherlands Fellowships Programmes (NFP);UNESCO-IHE;Asian Institute of Technology Fellowship ; |
| Degree | Thesis (M.Sc.) - Asian Institute of Technology - UNESCO-IHE, 2019 |