الفهرس 
الاستعراض المرجعي والإطار النظرييوجد فقط 14 صفحة متاحة للعرض العام
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المستخلص
The present supply of water seems to be constant and does not exceed 55.5 billions cubic meters. At the same time the demand of water is increasing with the increase of population and the need to expand agricultural land horizontally and this is cansirianed by the scarcity of water. The suspension of jongoli canal in the upper Nile as a result of disputes in the African continent made water supply limited. It is necessary therefore to rationalize water resources and follow new methods of managing water in irrigation.
The research study aimed at rationalizing water irrigation through development of irrigation water system in Behera governorate. Such improved irrigation system is examined through its effect on crop productivity per feddan and the estimated physical productivity per cubic meter of water for major crops in the area study by using different systems of irrigation water (the improved and unimproved area).
The study includes four chapters. The first is divided into two sections, The first section contains previous studies related to the subject of the study.
The second section include theoretical Framework, This first Part includes available water resources in addition to the non traditional water resources like the ground water in the valley and the delta, the treated waste water, drainage water and using modern technology in desalination for sea water, Part of this section include also some theoretical Framework such as production and cost functions in addition to some models.
The second chapter is concerned with the economic importance field crops in Behera governorate. The chapter is divided into two sections, The first section includes the sample of the study and Behera governorate is selected for the field study for its importance as it is the biggest in having major irrigation canal.
The second section includes the main crops according to its importance, such as wheat, cloves, maize, rice and cotton.
Water requirements per feddan were calculated for the main crops using questionnaire and compare aimer use by official water requirement. This show some misuse of water resource. Also using the simple regression to assess the effect of change in average productivity per feddan as the result of change in the quantity of water using improved and unimproved irrigation systems in the study area.
The average productivity per feddan is also calculated for the most important crops using both systems of water irrigation ( the improved and unimproved systems).
The estimated physical productivity per cubic meter of water for major crops in the study area, used by the different of systems irrigation water (the improved and unimproved area) the improved area gave higher yield than unimproved area for the crops wheat, cloves, maize, rice, cotton.
While the third section dealing with the outcome of a field study the environmental impacts to rationalize the use of water surface irrigation improvement and surface irrigation unimprovement the sample study, which was proved that the nature of the soil areas of the study is a black paned heavy.
The third chapter presents the statistical analysis of production and cost functions for the studied crops. The chapter came in three sections. The first includes Behera governorate as the sample to conduct the field study. The second section estimates production function for selected crops practicing the two types of irrigation system. The study shows that about 78% of changes in wheat in the developed irrigation system, was due to quantity of seeds, phosphate, labors and irrigation. Changes in wheat under non developed irrigation were due to the above factors except phosphate. As for cloves under developed irrigation system, 85% of its production was effected by quantity of seeds, phosphate, labors and irrigation.
Generally speaking, the above factors effecting production of maize, rice and cotton at varing degrees .
The third section estimates cost functions of the selected crops under developed and traditional irrigation system.
Quadratic equation was used to estimate economic efficiency of producing selected crops. The result show that the size that minimize cost and maximize profit was higher using developed irrigation system compared with non developed irrigation system in all crops studied .
The fourth chapter explains the economic effects of developed irrigation system in Behera governorate using some production and economic indicators . The chapter estimates water requirement for important crops under the two irrigation systems . Productivity per feddan was also estimated for the selected crops under the two irrigation systems. The results show the cultivation under developed irrigation system has led to a higher productivity per cubic meter and higher return per unit of water.