Rating Curve Modification at Low Discharges Using Physical Model Tests

Shun-Chung Tsung, Jihn-Sung Lai, Yun-Ling Chen, Hau-Wei Wang

Taiwan Typhoon and Flood Research Institute, National Applied Research Laboratories, Taipei, Taiwan.

DOI: 10.4236/wjet.2015.32005                

Abstract

Hydraulic structure is designed based on hydraulic theories or guidelines. To ensure performance, physical model tests are often used at high discharges. However, high discharge in river is rare. Physical model tests at high discharges will probably lead biased hydrological relationship. To improve hydrological relationship at low discharges, in this study, we considered the diversion rating curve of the Yuanshanzi Diversion Work. The 1/100-scaled physical model tests at low and high discharges (90 - 1620 m³/s) were performed and coupled the diversion discharges of 5 flood events (2009-2010) in field. The official diversion rating curve was built only based on physical model tests at high discharges (837 - 1620 m³/s). The results of physical model tests in this study suggested the official diversion rating curve should be modified considering all tests. The modifications showed the official diversion rating curve was over-estimated. A complete series of physical model tests and considering field situations, in this study, indicated expanded physical model tests and constantly field measurements were therefore necessary for hydraulic structure, which provided information to modify used hydrological relationship to fit real situations.

Keywords

Physical Model Test, Yuanshanzi Diversion Work, Rating Curve

Conflicts of Interest

The authors declare no conflicts of interest.

References

[1]	Transpot Association of Canada (2004) Guide to Bridge Hydraulics. Thomas Telford.
[2]	Bureau of Reclamation (1987) Design of Small Dams. Department of the Interior, Washington DC.
[3]	Water Resources Planning Institute (2011) Handbook of Hydraulic Model. Water Resources Agency, Nantun.
[4]	Water Resources Planning Institute (2002) Hydraulic Physical Model Tests of the Yuanshanzi Diversion Work in the Keelung River. Water Resources Agency, Nantun.
[5]	Kang, J., Kim, S. and Yeo, H. (2014) A Study on Physical Model Test for Cheongyeong Dam Discharge Recalculation. Engineering, 6,731-742. http://dx.doi.org/10.4236/eng.2014.611071
[6]	Ghobadian, R. and Meratifashi, E. (2012) Modified Theoretical Stage-Discharge Relation for Circular Sharp-Crested weirs. Water Science and Engineering, 5, 26-33.
[7]	10th River Management Office (2005) Operation and Maintenance Plan of the Yuanshanzi Diversion Work in the Keelung River. Water Resources Agency, Nantun.