The Four Major Rivers Restoration Project: Impacts on river flows
- 700 Downloads
The ongoing Four Major Rivers Restoration Project will drastically change the river environment of South Korea. The objective of this study is to evaluate the impact of the Four Major Rivers Restoration Project on river flows using an unsteady flow simulation model. The computational model was applied to the stream reaches of the Han River and the Nakdong River. Historical floods were simulated for the changed river environment as well as for the current river condition to investigate the flood mitigation effect of the project. The simulation results show that once the project is completed, the flood water level of the entire reach of both rivers will fall because water level decline due to the channel dredging dominates water level rise due to the presence of weirs. This mitigation effect was particularly significant for the upstream region of the Nakdong River because of large-scale dredging. A steady flow simulation was carried out using normal flow discharges to investigate the effect of the project on flow characteristics during non-flood periods. For the Han River, the normal water level rises upstream of the weirs, whereas it falls downstream owing to the dominant dredging effect. However, in spite of heavy dredging, the water level decline in the case of the Nakdong River is very limited because the effect of dredging is overwhelmed by the high normal pool level of the weirs. The increase in flow travel time of the Nakdong River after the completion of the project will be more significant than that of the Han River.
Keywordsthe Four Major Rivers Restoration Project unsteady flow model flood mitigation effect channel dredging weir
Unable to display preview. Download preview PDF.
- Cunge, J. A., Holly, F. M., Jr, and Verwey, A. (1980). Practical aspects of computational river hydraulics, Pittman.Google Scholar
- Doherty, J. (2000). Visual PEST: Model-independent parameter estimation, Watermark Computing & Waterloo Hydrogeologic, Waterloo, Ontario, Canada.Google Scholar
- Hill, M. C. (1992). A computer program (MODFLOWP) for estimating parameters of a transient, three-dimensional, ground-water flow model using nonlinear regression, Open-File Report 91-484, U.S. Geological Survey, Denver, CO, USA.Google Scholar
- Hill, M. C. (1998). Methods and guidelines for effective model calibration, Open-File Report 98-4005, U.S. Geological Survey, Denver, CO, USA.Google Scholar
- Holly, F. M., Yang, J. C., Schwarz, P., Schaefer, J., Hsu, S. H., and Einhellig, R. (1990). Numerical simulation of unsteady water and sediment movement in multiply connected networks of mobile-bed channels, IIHR Report, No. 343, Iowa Inst. of Hydr. Res., Iowa City, Iowa.Google Scholar
- IPCC (Intergovernmental Panel on Climate Change) (2007). Climate change 2007: Synthesis report, http://www.ipcc.ch/pdf/assessmentreport/ar4/syr/ar4_syr.pdf.
- Liggett, J. A. and Cunge, J. A. (1975). “Numerical methods of solution of the unsteady flow equations.” Unsteady Flow in Open Channels, K. Mohmmod and V. Yevjevich, Eds., Water Resour. Publications, Fort Collins, CO, pp. 89–182.Google Scholar
- MLTM (Ministry of Land, Transport and Maritime Affairs) (2009a), River maintenance planning report: The Han River (in Korean).Google Scholar
- MLTM (Ministry of Land, Transport and Maritime Affairs) (2009b), River maintenance planning report: The Nakdong River (in Korean).Google Scholar
- Woo, H. (2009). “Korea to launch a major project on river rehabilitation.” J. Hydr. Res., Vol. 47, No. 5, pp. 74–75.Google Scholar