The effect of side discharge pumping on flow and sediment transport in the Pumduang river, Thailand | |
| Author | Phai Sok Heng |
| Call Number | AIT Thesis no.WM-98-5 |
| Subject(s) | Sediment transport--Thailand--Surat Thani River engineering--Thailand--Surat Thani |
| 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 |
| Abstract | In order to supply the requirements of rice crop with the command area of 11,840 ha, water has to be pumped from the Pumduang river, Surathani Province, Thailand with a constant flow of 26-m3 I s. Under this effect of side discharge pumping, a dynamic balance between water and sediment moving in the natural stream condition will be changed. This disturbance of the equilibrium between sediment transport capacity of the river and sediment supply will induce morphological changes. The HEC-6 model which was developed by the Hydrologic Engineering Center, U.S. Army Corps of Engineer is a one dimensional numerical model for computation of variations of water surface and bed profile due to changing in flow and sediment transport boundary conditions in channel geometry. In this study the model has used to simulate the above mentioned problem, due to its success in applications to many other problems in the past 30 years. The simulated results under the various magnitudes of floods, namely low, average, 2, 10, 25, and 100 year flows are considered in this study. The model-input requirements are flow, sediment transport rate and river geometry for long-term simulation of the river under the effect of pumping. The model has been successfully calibrated based on the observed stage-discharge rating curve at station X6B and the measured equilibrium bed profile from the physical hydraulic model for the discharge of 10, 25, and 100 year return period flood flows. The HEC-6 model can only determined the general patterns of the water and sediment movement. To obtain more detailed information, a two dimensional model should be used, but it is much more complicated and time consuming. However, the results of one-dimensional model are useful in predicting the river response to changes and developing adequate management plans With constant pumping of 26 m3/s, the computed results of average bed changes downstream of pumping intake ranging from 0.086m to 0.16, and water surface drop ranging from 0.06 to 0.12m, under the effect of 10 to 100 year return period flood respectively. These results have been compared with the physical model results, which found to be very good. The computed results of water surface drop, flow velocity and bed changes, which have been determined under the effect of the project are found to be not significant. This means the project will not create any significant impact on the flow, sediment transport and river morphology of the Pumduang river on the long-term basis. |
| Year | 1999 |
| Type | Thesis |
| School | School of Engineering and Technology |
| Department | Department of Civil and Infrastucture Engineering (DCIE) |
| Academic Program/FoS | Water Engineering and Management (WM) |
| Chairperson(s) | Tawatchai Tingsanchali; |
| Examination Committee(s) | Sutat Weesakul;Kazama, So; |
| Scholarship Donor(s) | Royal Danish Government (DANIDA); |
| Degree | Thesis (M.Eng.) - Asian Institute of Technology, 1999 |