Flood risk analysis in Bangkok using GIS, remote sensing and a distributed flood model | |
| Author | Sin Wongwiwat |
| Call Number | AIT Thesis no.WM-04-26 |
| Subject(s) | Floods--Thailand--Bangkok Risk assessment--Remote sensing--Thailand--Bangkok Geographic information systems |
| Note | A thesis submitted in partial fulfillment of the requirements for the degree of Master of Engineering, School of Engineering and Technology |
| Publisher | Asian Institute of Technology |
| Series Statement | Thesis ; no. WM-04-26 |
| Abstract | This study aims at 1) analyzing the characteristic of floods in recent past and floods due to extreme rainfall events 2) developing a vulnerability database of the study area and 3) performing a distributed risk analysis. A distributed flood model with the aid of GIS and RS technologies is used for analyzing a risk of floods events in Bangkok due to extreme rainfall events. In this model, 1D-St. Venants equation with diffusive approximation is applied to simulate river network flow behavior. For overland flow, 2D-St. Venants equation with diffusive approximation is used. Simulation is done using 2 DEMs, SRTM and HYDRO1K. Modification of SRTMs DEM is done in order to reduce effect of building. Results from both DEM are compared. Extreme flood events are created from past rainfall data using IDF curve method and alternating block method. Questionnaire survey is conducted in order to acquire the vulnerability database and flood loss functions of the study area using linear regression analysis, weighted least square method and curve fitting method. Vulnerability database is created using Quickbird satellites image. Finally, flood impact was analyzed using result from hazard and vulnerability analysis. One of the most frequently flooded districts of Bangkok, Bangkapi and Buengkum district were chosen as the study area. Total area is about 54 sq.km. The model shows well simulation of canal flow pattern. The discrete surface flow simulation due to effect of DEM is found. Flood depth, flood duration and building area are found to be 3 most factors which affect flood loss. Inadequate warning time before flood is found. Effect of different DEM on flood simulation is addressed. Modification of DEM can improve surface flow simulation. Flood loss maps are created and total flood loss of past floods and flood due to extreme rainfall events are calculated. High flood risk areas are addressed. Finally, longer rainfall record is needed for more reliable extreme rainfall. Finer resolution DEM is needed for a better simulation result and effect of building grids in DEM must be reduced for a better flood simulation. |
| Year | 2005 |
| Corresponding Series Added Entry | Asian Institute of Technology. Thesis ; no. WM-04-26 |
| Type | Thesis |
| School | School of Engineering and Technology (SET) |
| Department | Other Field of Studies (No Department) |
| Academic Program/FoS | Water Engineering and Management (WM) |
| Chairperson(s) | Dutta, Dushmanta |
| Examination Committee(s) | Tawatchai Tingsanchali; Tripathi, Nitin Kumar; Sutat Weesakul |
| Scholarship Donor(s) | Royal Thai Government Fellowship |
| Degree | Thesis (M.Eng.) - Asian Institute of Technology, 2005 |