Economic Problem of Irrigation Canals: Seepage Losses

The economic feasibility of lining irrigation canals depends on several factors. Calculations aiming at the economic solution of the problem are generally complex and laborious. A method for simplifying these calculations, without lessening the precision of the results, is presented. The problem is defined in terms of functions having as the independent variable the canal water depth, by means of which all the factors are coordinated and connected. The method is applied to the case of a canal conveying a constant flow along the line, and to the case in which the discharge of a canal varies along the line itself. A numerical example is given to demonstrate application of the method to practical problems encountered in design.