CALCULATION OF THE NORMAL DEPTH IN AN IRRIGATION CANAL USING NEWTON'S METHOD

The paper considers the problem of calculating the normal depth of steady uniform flow in an irrigation canal of rectangular cross-section on the basis of Manning's formula. The resulting nonlinear equation is solved by Newton's method, and the result is compared with the bisection method. The normal depth, flow velocity and Froude number are computed for various discharges and roughness coefficients, and the stage–discharge curve of the canal is constructed.