| Author | Chowdhury, Shahadat Hossain |
| Call Number | AIT Thesis no. WA-89-02 |
| Subject(s) | Reservoir sedimentation
|
| Note | A thesis submitted in partial fulfilment of the requirements for the
degree of Master of Engineering |
| Publisher | Asian Institute of Technology |
| Abstract | When a dam is constructed across a stream to form a reservoir, the
velocity of the flow is reduced and a major part, or all, of the sediment is
deposited in the reservoir. On the other hand, the downstream portion of the
dam is eroded due to release of low sediment content water. The extent of
the sedimentation in the reservoir and the downstream degradation in the
long run of the dam is of utmost importance. The engineering feasibility of
the dam depends on the forecasting of that sediment behavior.
The sedimentation aspect of the proposal of Low Pa Mong Dam of 210
m MSL is investigated here. A one-dimensional mathematical model is developed
using the water continuity and momentum equation and sediment continuity
equation. The backwater solution is derived for unsteady flow condition and
then the morphological computations is done by the modified Lax scheme.
The calculations are carried out by developing a powerful computer program
in FORTRAN language. The model is calibrated for the year 1979 and 1980.
Then it is executed for the flood frequencies of 10 year and 50 year flow
and the change of the bed is predicted for 1 to 4 and 10, 30 and 50 years
period. The average river bed level change on the 200 km upstream as well
as downstream of the dam are plotted for that period and the morphological
changes of the average bed level have been obtained.
It is found from the study that the average rise of the bed in the
reservoir will be 2 m and 6 m and the downstream scour depth will be 1 m
and 3 m for a 10 year and 50-year lifetime of the darn which amounts
sedimentation of 160 million and 480 million cubic meter and erosion of 80
million and 240 million respectively. |
| Year | 1989 |
| Type | Thesis |
| School | School of Engineering and Technology (SET) |
| Department | Department of Civil and Infrastucture Engineering (DCIE) |
| Academic Program/FoS | Water Resources Research Engineering (WA) |
| Chairperson(s) | Suphat Vongvisessomjai;Preecha Kamronrithisorn; |
| Examination Committee(s) | Akiyama, Juichiro; |
| Scholarship Donor(s) | CIDA, Canada; |
| Degree | Thesis (M.Eng.) - Asian Institute of Technology, 1989 |