Your search found 9 records
1 Sharma, D. N.; Oad, R. 1990. Variable-time model for equitable irrigation water distribution. Agricultural Water Management, 17(4):367-377.
(Location: IWMI-HQ Call no: PER Record No: H06122)
(0.61 MB)
2 Hager, W. H.; Schwalt, M. 1994. Broad-crested weir. Journal of Irrigation and Drainage Engineering, 120(1):13-26.
(Location: IWMI-HQ Call no: PER Record No: H013876)
The low features over the broad-crested weir vertical upstream wall and sharp-crested corner are analysed experimentally. Only the long crested weir is considered, for which the discharge coefficient remains practically constant. For a relative overflow depth between 10% and 40%, the surface profile, the bottom pressure profile, the boundary separation profile, and the velocity profiles close to the upper corner are self-similar, provided effects of scale may be dropped. For extremely long-crested weirs, undular flow occurs. The first wave profile is shown to be identical with the solitary wave profile. The main properties of the undular hydraulic jump are explored. The broad-crested weir is characterized by insensitivity to tailwater submergence. The modular limit is found practically constant at 75% of the tailwater level, independent of the relative head on the weir. The discharge-head relation for submerged flow is analyzed under a novel approach. Finally, recommendations are specified under which a broad -crested weir may be used as a discharge measurement structure.
(Location: IWMI-HQ Call no: P 4386 Record No: H019865)
4 Skogerboe, G. V.; Merkley, G. P. 1996. Irrigation maintenance and operations learning process. Highlands Ranch, CO, USA: Water Resources Publications, LLC. x, 358p.
(Location: IWMI-HQ Call no: 631.7.1 G000 SKO Record No: H019955)
(Location: IWMI-HQ Call no: IIMI 631.7.1 G730 SKO Record No: H025316)
(0.81 MB)
6 Khan, A. H.; Lashari, B.; Khuwaja, M. A.; Memon, A. A.; Skogerboe, G. V. 1998. Water level fluctuations and discharge variability in the Mirpurkhas Sub-Division, Jamrao Canal, Nara Circle, Sindh Province, Pakistan. Hyderabad, Pakistan: International Irrigation Management Institute (IIMI). Pakistan National Program. ix, 31p. (IWMI Pakistan Report R-075 / IIMI Pakistan Report R-075) [doi: https://doi.org/10.3910/2009.549]
(Location: IWMI-HQ Call no: IWMI 631.7.1 G730 KHA Record No: H029991)
7 Khan, A. H.; Lashari, B.; Khuwaja, M. A.; Memon, A. A.; Skogerboe, G. V. 1998. Water level fluctuations and discharge variability in the Mirpurkhas Sub-Division, Jamrao Canal, Nara Circle, Sindh Province, Pakistan. Annexures. Hyderabad, Pakistan: International Irrigation Management Institute (IIMI). Pakistan National Program. pp.33-92. (IWMI Pakistan Report R-075 / IIMI Pakistan Report R-075) [doi: https://doi.org/10.5337/2011.001]
(Location: IWMI-HQ Call no: IWMI 631.7.1 G730 KHA Record No: H029992)
(3.73 MB)
8 Lashari, B.; Skogerboe, G. V.; Siddiqui, R. 1997. Hydraulic characteristics of pilot distributaries in the Mirpurkhas, Sanghar and Nawabshah districts, Sindh, Pakistan. Lahore, Pakistan: International Irrigation Management Institute (IIMI). Pakistan National Program. vii, 189p. (IWMI Pakistan Report R-028 / IIMI Pakistan Report R-028) [doi: https://doi.org/10.3910/2009.446]
(Location: IWMI HQ Call no: IIMI 631.7.1 G730 LAS Record No: H009212)
(6.03 MB)
(Location: IWMI HQ Call no: e-copy only Record No: H047437)
(0.99 MB)
Preliminary studies were conducted to test new design criteria incorporated in the Sefsafa Canal (SC) with the aim of reducing water application costs without sacrificing irrigation performance. For comparison, we also studied the Meet-Yazied Canal (MYC) (which is run without the new techniques). The cost-reduction measures used in this study included reduction of pump discharge rates and the use of electricity instead of diesel. We found that the location of farms along the irrigation canal had little effect on pump operation hours and amount of applied water; instead, crop patterns were the most important factor in this regard. The water use index (WUI), which is the ratio of applied water to required water, was higher in the SC than in the MYC and El-Mesk Canal (MC). Decreasing the pump discharge increased the amount of applied water to meet crop water requirements. During the winter, the WUI values of 1.11–1.16 achieved discharge rates of 70–80 l s-1 and were considered the optimal values of WUI. Further studies are required to avoid excessive application of water during the summer. The application of new techniques prompted farmers to irrigate their fields at night, thereby reducing water losses and installation and operational costs, and promoting equitable water distribution along the entire irrigation canal and throughout the command area.
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