الفهرس 
CHAPTER 1 : INTRODUCTIONOnly 14 pages are availabe for public view
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Abstract
Drained water is collected through 16000 km of open drains spread all over Egypt. Therefore, drains hydraulic problems lead to reduce their efficiency and ability to the free drainage of cultivated land. Sedimentation, side slope collapse, morphological change in the cross sections, spread of aquatic weeds and wrong application of maintenance methods consider the most important hydraulic problems that affect the hydraulic efficiency of drains. The work of the present investigation is based mainly on field data measurements along a seven of selected drains. The derived relations were developed taking into consideration the degree of the drains. For mathematical model, 1-D mathematical model (sobek 1-D) was used to simulate the studied open channel and verify the hydraulic performance for various operation circumstances. Also different operation scenarios would focus on increasing the hydraulic performance, especially to study the hydraulic impact after applying the rehabilitation process in specific reaches.
The main objective of this study is to study the impact of the hydrographic changing in the open drains cross sections on the hydraulic efficiency and the hydraulic characteristics of open drains, develop a new relations help in giving a set of rules that control the cross – sections to improve its efficiency, achieve the highest operating efficiency of open drains, increase the ability of open drains cross sections for conveyance and identify scientifically study about the maintenance program of open drains.