Flow Capacity Through Wide and Submerged Vegetal Channels
Publication: Journal of Irrigation and Drainage Engineering
Volume 118, Issue 5
Abstract
The presence of vegetation in irrigation canals in Egypt after the Aswan dam was built has become considerable problem in irrigation system. Many irrigation canals were designed by applying the common Manning's equation, but the presence of submerged weeds makes the application of Manning's equation for design of wide channels inadequate, because of the variation of the retardance coefficient over a wide range. Four canals were selected and considerable field data collection was carried out to identify the flow resistance and to modify Manning's equation. The velocity, slope, and discharge were measured in wide channels that had different capacities and that were filled with submerged vegetation (Potamogeton spp.) through the annual life cycle of weed growth. A more general discharge‐depth equation that offers advantages for a modified Manning's equation is developed based on the field data. A relationship was found between Manning's roughness coefficient for earth canals and an equivalent Manning's roughness for submerged weeds. The experimental setup is described and the results of the measurements are given.
Get full access to this article
View all available purchase options and get full access to this article.
References
1.
Bakry, M. F. (1989). “Effect of weeds on the flow characteristics open channels,” PhD thesis, Ain Shams University, Cairo, Egypt.
2.
Green, J. E. P., and Garton, J. E. (1981). “Improved design procedures for vegetation‐lined channels.” ASAE Paper No. 81‐2105, American Society of Agricultural Engineers (ASAE), St. Joseph, Mich.
3.
Gwinn, W. R., and Ree, W. O. (1980). “Maintenance effects on the hydraulic properties of a vegetation‐lined channel.” ASAE J., 23(3), 636–642.
4.
Khattab, A. F., and El‐Gharably, Z. (1987). “Problems of aquatic weeds in irrigation system and methods of management.” Proc., 6th Afro Asian Region Conf., Int. Commission on Irrig. and Drain (ICID), Cairo, Egypt, Vol. 2, B6–B6.17.
5.
Ree, W. O. (1949). “Hydraulic characteristics of vegetation for vegetated waterways.” Agric. Engrg., 30(4), 184–189.
6.
Ree, W. O. (1952). “The use of grass in waterways.” Proc., 6th Int. Grassland Congress, State College, Pa., 991–996.
7.
Ree, W. O. (1959). “Permissible velocities in vegetation lined conservation channels.” Compilation manual of paper prepared for the ScS‐ARS sedimentation workshop, Soil Conservation Service, USDA, Oxford, Miss., 7.1–7.9.
8.
Ree, W. O. (1977). “Friction factors for vegetated waterways of small slope.” ARS‐S‐151, U.S. Dept. of Agriculture, Washington, D.C.
9.
Turner, A. K., and Chanmeesri, A. (1984). “Shallow flow of water through non‐submerged vegetation.” Agric. Water Mgmt., 8(1984), 375–385.
Information & Authors
Information
Published In
Copyright
Copyright © 1992 ASCE.
History
Published online: Sep 1, 1992
Published in print: Sep 1992
Authors
Metrics & Citations
Metrics
Citations
Download citation
If you have the appropriate software installed, you can download article citation data to the citation manager of your choice. Simply select your manager software from the list below and click Download.