الفهرس 
LITERATURE REVIEWOnly 14 pages are availabe for public view
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Abstract
Local scour is one of the tedious complicated problems, concerning a variety of irrigation works, like dams, barrages, and weirs, built in alluvial rivers and canals. There are many scour varieties of local scour systems downstream heading up structures; each with its own particular geometry and hence local scour mechanism. This study was carried out in the hydraulic laboratory for studying the effect of using stilling basins on the local scour phenomenon, which occurs downstream hydraulic structures. A sum of about 333 experiments were carried out for different gate openings, flow conditions, and dimensions of stilling basins, using two values of sand grain sizes as bed material. This study was carried out in laboratory for downstream Froude number ranged from 0.26 to 0.45, to find non dimensional relationships among the design parameters. Based on the Buckingham theory, the technique of the dimensional analysis is employed in order to develop the proper correlations, which are needed for defining the scour size. Empirical relationships implying the dimensions of the stilling basins, flow conditions, bed material and scour hole parameters were developed from dimensional analysis based upon the data obtained from the experimental tests. Generally, the obtained results showed acceptable fittings between the different parameters. Also, the results indicated that the dimensions of the scour hole was decreased with both increasing the length of the stilling basin and the decrease of the downstream Froude number.