Paper Information

Journal:   JOURNAL OF SOIL AND WATER RESOURCES CONSERVATION   WINTER 2017 , Volume 6 , Number 2; Page(s) 105 To 119.
 
Paper:  MODIFYING EMPIRICAL EQUATIONS OF SEEPAGE ESTIMATION USING DIMENSIONAL ANALYSIS (BOLDAJI EARTH CANAL, CHAHARMAHAL AND BAKHTIARI PROVINCE)
 
Author(s):  TAVAKOLI EHSAN*, GHORBANI BEHZAD, SAMADI BOROUJENI HOSSEIN, RADFAR MEHDI, GHAHRAMAN BIJAN
 
* DEPARTMENT OF WATER ENGINEERING, SHAHREKORD UNIVERSITY, SHAHREKORD, IRAN
 
Abstract: 

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 (< 3.2 liters) in comparison with measured values, after the calibration of the empirical equations for the study region and modifying their coefficients, the modified Moritz and Ingham selected as the best methods. All equations estimated the seepage loss much smaller than the measured values, which was rectified after modifying the coefficients. Utilizing dimensional analysis and transferring canal conditions to laboratory was resulted in lowering costs and less time, that according to acceptable and similar to previous studies results, it could be suggested to apply in controlled conditions of laboratory for other regions.

 
Keyword(s): INFILTRATION AND SEEPAGE, INGHAM METHOD, MORITZ METHOD, PHYSICAL MODEL