| Author | Nguyen Huu-Thoi |
| Call Number | AIT SSPR no. WA-89-07 |
| Subject(s) | Hydraulics--Mathematical models
|
| Note | A special study submitted in partial fulfilment of the requirements for the degree of Diploma AIT, School of Engineering and Technology |
| Publisher | Asian Institute of Technology |
| Series Statement | Special studies project report ; no. WA-89-07 |
| Abstract | Due to the need to know the backwater effect from the Mekong
river at Pakse along the Sedone river, this special study on
mathematical simulation of flow in the Sedone river is then made.
A one-dimensional finite difference model is developed to
simulate the hydraulic conditions of the river consisting of two
subsystems, namely Subsystem 1 from Muang Souvannakhili to Ban
Dong Gnang and Subsystem 2 right downstream from the weirs to
Pakse at the Mekong River. The division of the river into two
subsystems is made at the Selabam Fall where unknown energy loss
exists. The developed mathematical model is successfully applied
to the simulation of flow in Subsystem 1. However, the model
would not work well for Subsystem 2 unless some modifications of
riverbed would be introduced due to the complexity of the topographical
condition in the vicinity of the powerhouse and a
significant drop of the riverbed.
Calibrations and simulations are carried out for the flows
from June to October, using data available in 1987. The results
obtained from calibrations show that the roughness coefficients
applied to the system are variable, depending on flow conditions
(low, medium or high flow) and local topographic conditions of
the reaches of the river. The values of Manning's n are highest
for low flow. Based on the computed data together with observed
data, the rating curves at a number of stations along the
considered river system are developed. There is a good
agreement between these developed rating curves with those developed by TATA Consulting Engineers for most of the stations.
The results show that the looping rating occurs for Gauge No. 9.
A study on the effect of highwater levels at Pakse on the water
levels at Tailrace is also conducted. It is found from the study
that the effect of backwater goes very far upstream from Pakse.
However, the backwater effect would not reach Gauge No. 4 (Tailrace) when the water levels at Pakse are less than 102.40 m MSL. |
| Year | 1989 |
| Corresponding Series Added Entry | Asian Institute of Technology. Special studies project report ; no. WA-89-07 |
| Type | Special Study Project Report (SSPR) |
| School | School of Engineering and Technology |
| Department | Department of Civil and Infrastucture Engineering (DCIE) |
| Academic Program/FoS | Water Resources Research Engineering (WA) |
| Chairperson(s) | Suphat Vongvisessomjai |
| Degree | Special Studies Project Report (M. Sc.) - Asian Institute of Technology, 1989 |