Hydraulic Rougnness Of Irrigation Ganals

Hydraulic roughness of alluvial channels is considered one of themain factors affecting the flow discharge.Therefore, the ann of the present study is to evaluate the hydraulicroughness of some canals in Sharkia Governorate. After careful surveyingand site inspection, five canals were selected to represent the irrigationnetwork III Sharkia the selection was including different degrees ofcanals. The selected canals are Bahr Abou EI- Akhdar , Bahr Faqous andBahr Mowais, as main canals. EI- Samaana and Bahnabay canals werechosen as distributary canals. It’s discharge covered a wide range of flowdischarge which was from 3.11 to 82.87 m 3/s.Samples of soil of the boundaries material were collected and analysedfor determining the grain size distribution.A regression analysis was carried out for field collected data. Thedata included water levels of the canal intake structure, water depthswithin the cross sections, average velocity, top width of the flow crosssection, and water surface slope. The relationship between the flowdischarge versus down stream water level, cross- sectional area, hydraulicradius, and average velocity were plotted. Manning’s equation was usedto estimate the hydraulic roughness coefficient ”n” in the study.Buckingham’s Pi theorem was used to develop a relationship to becorrelated with hydraulic roughness n. Two empirical equations weredeveloped for estimating the hydraulic roughness n as a function of the