Regime equations development for the design of Egyptian sandy canals

Abstract

The construction of the High Aswan Dam in Egypt led to reducing the solid suspension in water from more than 3,500 p.p.m. to less than 100 p.p.m. As the regime of Egyptian canals has been changed completely after the construction of the High Aswan Dam, the previous derived equations are not applicable anymore, and using them leads to a shortage in the carrying capacity of the canals. In the current study, extensive field measurements have been carried out on 15 Egyptian stable canals, which cover various discharges of irrigation canals starting from 5 m3/s to 50 m3/s with sandy soils and d50 range from 0.196 to 0.538 mm. Then, applicable regime relationships for designing stable sandy channels were determined. The new equations are useful for designing new stable canals and redesigning unstable canals within the same range. The new regime equations were verified by using HEC- RAS program. Finally, sensitivity analysis has been performed in order to investigate the effect of changing the deduced parameters on the discharge.