الفهرس 
ACKNOWLEDGEMENTS
OBJECTIVES OF THE STUDYOnly 14 pages are availabe for public view
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Abstract
ABSTRACT
Floating vegetation is commonly appeared in canals,rivers, lakes and wetland marshes. Existing knowledge on the interaction of floatingvegetation (such as water hyacinth) with the flow in canals and the consequences of this interaction to flow characteristics is limited.The inability to calculate the effect of most types of floating vegetation on channel conveyance prevents the development of projects that include appropriate floating vegetation that provides both environmental benefits and required conveyance.
Effective management of flow in irrigation canals requires knowledge of the canals’ capacity when they are impacted by the floating vegetation. So, this study aims to investigate the effect of floating vegetation (water hyacinth) on flow behavior within open channels.
The experimental work was carried out using a rectangular, circulating water flume with dimensions (10 m long, 0.3 m wide, and 0.3 m deep). The vegetation (water hyacinth) was collected from natural streams. The experimental runs were carried out with four vegetation densities (λ_v=30,60, 90,120 pieces/m^2), three vegetation root depths (K_v=1, 3, 5 cm), three vegetation zone lengths (L_v=1, 2, 3 m) with smooth and rough channel bed. Four discharges (10, 12, 14, 16 L/s) were passed through the flume.
The objective of the study presented herein is to investigate:
• The effect of water hyacinth density and its root depth on vertical velocity profile for smooth and rough bed channel.
• The effect of water hyacinth variables (density, root depth, zone length) on water surface profile for smooth and rough bed channel.
• The effect of water hyacinth variables (density, root depth, zone length) on heading up.
• The effect of water hyacinth variables (density, root depth, zone length) on flow discharge.
• The effect of water hyacinth variables (density, root depth, zone length) on equivalent roughness of channel.
• The effect of water hyacinth variables (density, root depth, zone length) on vegetation drag force.
from the test results, the following main conclusions were drawn:
1. Water hyacinth density, its root depth and bed roughness have a significant effect on vertical velocity profile and the position of maximum velocity.
2. Water hyacinth variables have a great effect on water surface profile in both cases, smooth and rough bed.
3. The heading up increases by increasing vegetation density, vegetation root depth and vegetation zone length.
4. The flow discharge through channel decreases by increasing vegetation density, vegetation root depth and vegetation zone length.
5. The equivalent Manning’s roughness coefficient of channel increases by increasing vegetation density, vegetation root depth and vegetation zone length.
6. The vegetation drag force increases by increasing vegetation density, vegetation root depth and vegetation zone length.
7. Multiple regression analysis equations based on the dimensional analysis concept were deduced for computing the heading up, flow rate, equivalent manning’s roughness coefficient and vegetation drag force.