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Sedimentation in the Gorai River offtake in Bangladesh | |
Author | Navera, Umme Kulsum |
Call Number | AIT Thesis no. WM-95-09 |
Subject(s) | Sediment transport--Bangladesh--Gorai River |
Note | A thesis submitted in the 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-95-09 |
Abstract | The Southwest region of Bangladesh is surrounded and crossed by several rivers. Among these rivers the Gorai is one of the most important distributary in that area. The Gorai draws water from the Ganges and is the main supplier of fresh water to the southern region. However, in the recent years the flow in this river is observed to be gradually decreasing during the dry season. The main objective of this study is to find the reasons behind the reduction of flow which even drops below the critical level during the dry season. An effort has been made in this thesis research to identify the reasons for this substantial reduction in annual flow by analyzing historical and recent data. An extensive hydrological and morphological analysis has been made to assess the present situation. The behavior of the Ganges-Gorai river system has been predicted based on the analysis of the cross-sectional, water level, flow discharge and sediment transport data. Time series of historical and recent data has been used for this study. Emphasis has also been given to obtain the present morphological condition. The morphological changes at the offtake is directly responsible for lowering of flow in the Gorai river. The recent funnel shape formation of the Gorai offtake attracts huge sediments from the Ganges river which results in sedimentation at the offtake. The flow in the Gorai is not sufficient enough to wash away the deposited sediment, therefore, the net sediment deposition increases every year building up sediment bar at the offtake. The sediment bar obstructs the flow from the Ganges to the Gorai. To maintain essential fresh water flow through the Gorai throughout the year, dry season augmentation of the mouth is necessary for conveying water to the Southwest region of Bangladesh. |
Year | 1995 |
Corresponding Series Added Entry | Asian Institute of Technology. Thesis ; no. WM-95-09 |
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) | Kyotoh, Harumichi;Sutat Weesakul; |
Scholarship Donor(s) | DANIDA, Royal Danish Government; |
Degree | Thesis (M.Eng.) - Asian Institute of Technology, 1995 |