الفهرس 
Classification of Irrigation and Drainage NetworksOnly 14 pages are availabe for public view
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Abstract
The irrigation network in Egypt suffers from several hydraulic issues such as changing in canal geometry (scouring and siltation) which may have occurred due to faulty design or insufficient maintenance programs. That is why Al-Rayah Al-Tawfiky is selected for this research. A hydraulic surveying was conduct; using a high technology instrument to simulate the actual hydraulic efficiency for the area of study. Furthermore, identifying the main objectives of the research as determining the reaches of the canal, which need rehabilitation, based on the analysis of actual collected data, to deduce an empirical equation relating the hydraulic parameters, and to state the hydraulic effects of rehabilitating the most effective reaches on the hydraulic performance of Al-Rayah Al-Tawfiky. For this purpose, different rehabilitation scenarios were simulated using SOBEK1D model. The results for each scenario take into consideration water levels, velocities, and discharge at different locations along Al-Rayah Al-Tawfiky.
An economic study is conducted to clarify the benefit from implementing the suggested rehabilitation works, besides comparing the economic income, and the rehabilitation costs.
Chapter One:-
This chapter includes a general introduction about the problem of the current research, and the influence of the cross section’s morphological changes on the hydraulic efficiency of the open channel. This chapter also involves the research objectives, besides the contents of the thesis.
Chapter Two:-
This chapter contains the literature review that deals with the research point “the hydraulic efficiency of open channel”, and the major hydraulic problems that affect on the performance of irrigation canals. In additional it reviews the impact of implementing the unsuitable maintenance programs on the irrigation network’s efficiency. This chapter also includes a chronology for the scientific researches, papers, theses, and previous studies that deals with the current research topic.
Chapter Three:-
This chapter reviews the dimensional analysis by using Buckingham’s theory to deduce an empirical equation which relating the effective parameters on the conveyance efficiency as: the flow discharge (Q), velocity (V), the flow capacity of the cross sections (Aw), the scour area (Asc.), sediment area (Ased.), the hydraulic radius (R), the wetted parameter (P), top width (Tw).
A new empirical equations have been deduced to determine the conveyance efficiency in open channel.
〖AR〗^(2/3)=A^(4/3) .f(A_(sc )⁄A_(dp ) ,R⁄P ,T_w⁄√A ,Q⁄(A.V ))=0
Chapter Four:-
This chapter includes the executed field measurements that contains the design, and the actual data of Al-Rayah Al-Tawfiky at the case study area. The design data include the designed details of El Rayah El Tawfiky, sub-canals that feed directly from Al-Rayah Al-Tawfiky (i.e. the designed longitudinal section, the designed bed levels, the designed water levels, recent actual water levels and discharges daily over the year), and the designed data of structures along Al-Rayiah Al-Tawfiky (i.e. location of Bridges, its designed width and its crest levels).
The actual data include: a surveying works of (344) three hundred and forty four actual cross sections were measured (cross section every 100m) before implementing the rehabilitation works in 2014, a surveying works for one hundred and twenty three (123) rehabilitated cross section were measured (cross section every 129m) in 2018.
The flow measurements have been carried out as follows; the discharges at six (6) locations along Al-Rayah Al-Tawfiky were measured, In addition the discharges of the sub-canals which are fed directly from Al-Rayah Al-Tawfiky were also measured.
Chapter Five:-
This chapter reviews the used mathematical model (SOBEK 1D) in the current research, and identifying the govern equations of the model. In additional to identify the model inputs, and outputs.
The model calibration is the practical of controlling the model parameters, and limit the uncertainties of hydrodynamic variables by matching the model results with the actual measurements. Validation of the model was achieved based on actual field measurements (discharges, and water levels). These measurements were implemented by Channel Maintenance Research Institute (CMRI) team. Then the assessments between simulated and measured discharges and water levels show a good agreement between the model and the prototype.
Chapter six:-
This chapter involves the analysis of the results. The results of the mathematical model (SOBEK 1D) are presented in charts that clarify the influence of rehabilitation length (LR), and the rehabilitation location on the water surface profile, and the flow velocity distribution along Al-Rayah Al-Tawfiky.
The analysis of the aforementioned results of the suggested rehabilitation cases yielded the following conclusions:
The sedimentation area (A_(sed. )) affects on the conveyance parameter more than the other hydraulic characteristics.
Water surface profile upstream the rehabilitation works have an inverse relation with rehabilitation length (L_R).
The rehabilitation works have no effect on water surface profile in the downstream reach (the rehabilitated water surface profile is the same as the actual water surface profile).
The rehabilitation works decrease the velocities distribution along the rehabilitated reach.
The rehabilitation do not have a significant effect on the water velocity distribution until the rehabilitation length (L_R) exceeds 50% of total rehabilitation length.
Whenever the rehabilitation length (L_R) increases, the value of the increasing rate in discharge (∆Q_in) increases.
At the same rehabilitation length (L_R), the case of fixed water level at downstream has a produced water surface profile lower than the case of the variable water level.
Implementing the rehabilitation works increase the capacity of Al-Rayah Al-Tawfiky by 25%, and 22.5% of actual inlet discharge for the fixed W.L case and the variable case respectively. This improving the capacity to be 97.01%, and 95.07%) respectively of the designed inlet discharge (Q_(in-Design)).
By studying the results there is a direct relation between the rehabilitation length (L_R), and the value of the increasing rate in discharge (∆Q_in), and the relations are expressed in the following equations:
In Case (Variable Water Level at downstream):
(∆Q_in%)=0.1905 (L_R%) + 0.8107
In Case (Fixed Water Level at downstream):
(∆Q_in%) = 0.1905 (L_R%) + 0.0299
The economic study clarified that the rehabilitation scenarios; when the water level at Jamjara Regulator is fixed, and variable are profitable for the stakeholders.
The rehabilitation works increase the cultivated land in case the water level at Jamjara Regulator is fixed more than in case of variable water level.
The rehabilitation works increase the cultivated land by 10.01%, 9.01% when the water level at jamjara is fixed, and variable in respectively. The maximum improving percentage in the cultivated area respecting to rehabilitation length is 81.98%, 80.97%, where the maximum improving percentage in the cultivated area respecting to the rehabilitation location is 77.95%, and 76.95.
Chapter Seven:-
The objective of this chapter is to introduce a conclusion of the whole research, the obtained results, and recommendations for further researches.