| Author | Nguyen Hoang Son |
| Call Number | AIT Thesis no.WM-05-3 |
| Subject(s) | Floods Vietnam Mathematical models Flood forecasting Vietnam Mathematical models
|
| Note | A thesis submitted in partial fulfillment of the requirements for the
degree of Master of Engineering. |
| Publisher | Asian Institute of Technology |
| Abstract | Floods in Central Vietnam occur every year and cause property damages and losses of life. Shape of basins in central Vietnam is quite concentrated and terrain is quite steep, so the flood water level goes up and down very fast. Moreover, floods always fluctuate making flood forecasting becomes difficult in this area. In this study, hydrologic models HEC-HMS and hydrodynamic model HEC-RAS are used to simulate flood in Vu Gia- Thu Bon river, Quang Nam - Da Nang province, Central Vietnam. The HEC-RAS model is applied to route flood from two stations which are Nong Son at upstream of Thu Bon river and Thanh My at upstream of Vu Gia river, to two downstream boundaries which are Han mouth in Da Nang city and Dai mouth at Hoi An district in Quang Nam province. The results of HEC-RAS model are used to prepare inundation map to determine flooded area at floodplain by HEC-GEORAS which are an extension of Arcview-GIS. In addition, a database management program is created by Visual Basic and Microsoft Access combining with GIS application to store, to display, to query and to assist flood forecasting. The floodplain in downstream area is divided into 15 storages, in which each storage is separated by roads, railways, etc. The connections between two storages are simulated by a spillway or gate. Runoff from floodplain or ungaged area is divided into 12 sub-basins with basin areas ranging from 200 to 600 km2 and hydrologic software models HEC-HMS are applied to calculate runoff from rainfall. The model parameters are selected from calibration result. The outflows from 12 sub-basins are inflows into 12 storages which are the boundaries of the hydrodynamic model. The output of HEC-HMS is input of HEC-RAS model and it is auto-connected by DSS files. Rainfall input for HEC-HMS is hourly rainfall which is simulated from hourly rainfall observed stations. Calibration results of HEC-HMS for flood in 1998, 1999 at Nong Son and Thanh My station with EI range from 0.85 to 0.99 and a set of validation parameter is selected. The results of HEC-RAS model are obtained at Giao Thuy station on Thu Bon river with El range from 0.7 to 0.95 and Ai Nghia station on Vu Gia river with El range from 0.72 to 0.9. These results are applied for flood in 2004 with El = 0.88 at Giao Thuy station and El = 0.92 at Ai Nghia. The predicted flooded area is compared reasonably well with floodplain archived by Landsat images |
| Year | 2006 |
| 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;Clemente. Roberto S.; |
| Examination Committee(s) | Gupta, Ashim Das;Babel, Mukand Singh ; |
| Scholarship Donor(s) | AIT Fellowship; |
| Degree | Thesis (M.Eng.) - Asian Institute of Technology, 2006 |