Bed roughness at the confluence of the Ganges and Jamuna Rivers in Bangladesh | |
| Author | Piru, Israt Jahan |
| Call Number | AIT Thesis no.WM-97-14 |
| Subject(s) | Bed load--Ganges River Bed load--Jamuna River |
| Note | A thesis submitted in partial fulfillment of the requirements for the degree of Master of Engineering, School of Civil Engineering |
| Publisher | Asian Institute of Technology |
| Series Statement | Thesis ; no. WM-97-14 |
| Abstract | River flow and sediment transport distribution are estimated with considerable accuracy for the prediction of short term morphological changes in a river systems. These two, again, are dependent on the bed roughness conditions. In a two dimensional morphological model it is, therefore, required that the variation in bed roughness is predicted with sufficient degree of accuracy. The bed roughness character at the confluence of Ganges and J amuna river has been investigated in the present study in connection with flow, sediment transport and bedform parameters. The study findings will provide Jamuna Bridge Authority with an understanding of the bed roughness and sediment transport characteristics of the river which will help them attaining a proper maintenance methodology. The Chezy coefficient has been found to depend strongly on the energy gradient, depth of flow and on flow stages responsible for modifying the bedforms. Comparison with the original Chezy C , it is found that none of the roughness prediction methods could predict the strong variability of roughness coefficient values present at the confluence of Ganges and Jamuna river. Therefore, two new methods have been proposed that can be used in two dimensional morphological computation and the verification results shown that over 89% data falling in the accuracy factor range of 0.7-1.3. Proposed equations have been applied to sediment transport computations. Although significant variation of exponent 'n' in sediment transport formulations has been observed, however, transport rates are generally less affected considering the high uncertainty associated with such predictions. |
| Year | 1998 |
| Corresponding Series Added Entry | Asian Institute of Technology. Thesis ; no. WM-97-14 |
| Type | Thesis |
| School | School of Civil Engineering |
| Department | Department of Civil and Infrastucture Engineering (DCIE) |
| Academic Program/FoS | Water Engineering and Management (WM) |
| Chairperson(s) | Suphat Vongvisessomjai; |
| Examination Committee(s) | Tawatchai Tingsanchali;Sutat Weesakul;Paudyal, Guna Nidhi; |
| Scholarship Donor(s) | DANIDA; |
| Degree | Thesis (M.Eng.) - Asian Institute of Technology, 1998 |