Changes in hydraulic parameters in canals with sides lining

Abstract Today, as a result of deformation and filtration in the channel, hydraulic efficiency operational reliability irrigation networks our Republic is decreasing, result, 0.63 percent. In order to provide agricultural producers with required amount water on time, systematic work being carried out increase basis several state programs. Concreting channel can be an effective solution these problems, but economic costs involved are causing delays implementation works. When reconstructing canals, choosing concreting scheme taking into account type problem. Under conditions limited filtration, both sides canal leads efficiency. However, there problem connect roughness coefficients natural soil concrete calculation canals. The article presents research conducted 4th section Big Fergana Canal, according results, n=0.0195 two-sided concreted (PK-2010+85) part, n=0.022 earthen part (PK-2020+85). was modeled HEC-RAS 5.0.1 based elements PK-2010+85, coefficient n=0.0199.