On Evaluation for Effectiveness of Reducing River Discharge with the Irrigation Tank System Lied on a Plain
Grant-in-Aid for Scientific Research (C)
|Allocation Type||Single-year Grants|
Irrigation, drainage and rural engineering/Rural planning
|Research Institution||Kagawa University|
KAKUDO Hirofumi Kagawa University, Faculty of Engineering, Associate Professor, 工学部, 助教授 (30253256)
MORISHITA Kazuo Kagawa University, Faculty of Engineering, Associate Professor, 工学部, 助教授 (80036061)
KAWAHARA Yoshihisa Hiroshima University, Graduate School of Engineering, Professor, 大学院・工学研究科, 教授 (70143823)
MORITA Hidenori Okayama University, Faculty of Environmental Science and Technology, Associate Professor, 環境理工学部, 助教授 (60239663)
|Project Period (FY)
2002 – 2004
Completed(Fiscal Year 2004)
|Budget Amount *help
¥3,500,000 (Direct Cost : ¥3,500,000)
Fiscal Year 2004 : ¥600,000 (Direct Cost : ¥600,000)
Fiscal Year 2003 : ¥500,000 (Direct Cost : ¥500,000)
Fiscal Year 2002 : ¥2,400,000 (Direct Cost : ¥2,400,000)
|Keywords||Irrigation tank / Storage Function / Restraining river discharge / Storage Operation / Water uses with customs / 貯留機能|
Effectiveness to reduce runoff in a river basin containing irrigation tank systems laid on a plain was evaluated. The Shimizu River (CA=2.8km^2, L=2.5km) as a model on this research contains 14 irrigation tanks and their related channels. Surface area of all of the irrigation tank systems including related channels accounts for 23.7 percent of the catchments area.
For the evaluation of effectiveness of irrigation tank systems, scenarios were considered as follows ;
- both present irrigation tank systems and present water management for irrigation will be sustained in the future (Case A),
- both all of the irrigation tank systems and their storage function will be abandoned (Case B),
- present irrigation tank systems will be sustained, besides operation and management of the systems will be modified to reduce runoff in a river basin further (Case C).
Based on precipitation data at Typhoon 15 in August and Typhoon 23 in October, 2005, runoff model of The Shimizu River was run by Kinematic Wave Method. For the Case B, temporary storage of rainfall upon the basin is not taken into account, because of loss of capacity on the irrigation tank systems.
Although calculated peak discharge was 9.1m^3/s at Typhoon 15 and 10.1m^3/s at Typhoon 23 respectively on the Case B, calculated peak discharge was 4.2m^3/s at Typhoon 15 and 5.4m^3/s at Typhoon 23 respectively on the Case A. These results show that an effect on the Case A caused an about 46 through 53 percent decrease in peak discharge under a condition of precipitation on this research.
For strengthening effectiveness to reduce runoff discharge such as the Case C, it was pointed out that selection of a suitable irrigation tank system taking into consideration arrangement and storage capacity would be important.
Research Products (16results)