Modifying empirical equations of seepage estimation using dimensional analysis (Boldaji earth canal, Chaharmahal and Bakhtiari province)

The high amounts of losses from irrigation canals have resulted in lining the conveyance canals being as an important measure in order to increase water conveyance efficiency. The economical justification of earthen canals lining requires investigating the amount of seepage and infiltration in such canals. In this study, using a physical model and dimensional analysis, the water seepage loss from Boldaji earthen canal, Borujen city, Chaharmahal and Bakhtiari province, with loamy soil, was determined in the range of 40 to 100 liters per second flow rates. The empirical equations such as Moritz, Ingham, Molesworth and Yennidumia, Offengenden, Davis-Wilson and Indian equations were chosen for seepage estimation. Results showed that before modifying the coefficients of equations, the results of the modified Ingham have the highest correlation coefficient (0.917) with measured values. Independent variables of this method are water depth, canal length and wetted perimeter. Allocating the highest value of R2 (> 0.90) besides the lowest value of RMSE (