Document Type : Research Paper

Authors

1 PhD Scholar, Department of Water Engineering, Faculty of Agriculture, Imam Khomeini International University, Qazvin, Iran

2 Assoc. Professor, Agricultural Engineering Research Institute, Agricultural Research, Education and Extension Organization, Karaj, Iran

3 Assoc. Professor, Department of Water Engineering, Faculty of Engineering, Imam Khomeini International University, Qazvin, Iran

Abstract

Today, proper and sustainable use of water and soil resources is on the agenda of executive agencies. Therefore, optimum design of drainage systems is very important. Effective porosity and soil hydraulic conductivity coefficients should be determined with acceptable precision. In addition, it is essential to evaluate the drainage equation for the unsteady subsurface under farm conditions. This research was carried out in subsurface drainage system in Shadegan Plain. The effective porosity and soil hydraulic conductivity were determined by measuring the time, the height of water table, and the discharge outlet from the lateral drain. Moreover, through inverse solving, the soil effective porosity and hydraulic conductivity in Shadegan Plain were estimated. The mean effective porosity calculated using Taylor method was 0.0117 (dimensionless) and the mean soil hydraulic conductivity calculated by Skaggs method was 0.31 m/d. In following, using measured data of time and height of water table and also prevalent unsteady subsurface equations, the drain intervals were estimated. The calculated distance was analyzed with 50 (m) measured distance. The evaluations showed that the Glover, Dumm, Van Schilfgard, Bouwer and Van Schilfgard, modified Glover and Hammad equations have priority repectively. In using unsteady drain equations, it should be noted that it is not possible to prioritize specific equation. On the other hand, for each region, these equations must be evaluated individually and the best equation must be selected.

Keywords

Main Subjects

Boroomand Nasab S. (1996). Evaluation of drainage formulas in non-uniform state with collection of data and field information. M.Sc. Dissertation, University of Shahid Chamran Ahwaz, Ahwaz. 223 pp [In Persian].
 
Gupta S. K. (2002). A century of subsurface drainage research in India. J. Irrig. Drrain. Sys., 16(1), 69-84.
 
HaghayeghiMoghadam S. A. (2016). Recommendations for optimizing the design of the subsurface drainage network. Amoozesh Keshawarzi Nashr, Karaj, Iran [In Persian].
 
HaghayeghiMoghadam S. A., Akhavan K., Khwaja Abdullahei M. H., Azizi A. and Naseri A. A. (2005). Evaluation of the relation between subsurface drainages in Ardebil and Khuzestan. Amoozesh Keshawarzi Nashr, Karaj, Iran [In Persian].
 
HaghayeghiMoghadam, S. A., Dehghanian, S. E., Akhavan, K. (2007). Investigating and verifying the efficiency of suitable formulas for determining the distance of subsurface drainage. Amoozesh Keshawarzi Nashr, Karaj, Iran [In Persian].
 
Kumar R., Bhakar S.R., Jhajharia D. and Morvejalahkami B. (2012). Evaluation of drain spacing equations in the Indira Gandhi Canal command area, India. ISH J. Hydraul. Eng., 18:3, 186-193.
 
Momeni A. (2010). Geographic distribution and salinity levels of Iranian soil resources. J. Soil Res., 24(3), 203-215 [In Persian].
 
Pali A. K. (2013). Evaluation of non-steady subsurface drainage equations for heterogeneous saline soils: a case study. IOSR J. Agri. Veter. Sci., 6(5), 45-52.
 
Pali A. K., Katre P. and Khalkho D. (2014). An unsteady subsurface drainage equation incorporating variability of soil drainage properties. Water Resour. Manag., 28(9), 2639-2653.
 
Prakash A. (2004). Water resources engineering: Handbook of essential methods and design. American Society of Civil Engineers. Reston, Virginia.
 
Skaggs, R. W. (1976). Determination of the hydraulic conductivity-drainable porosity ratio from water table measurements. Trans ASAE, 19, 73–80
 
Skaggs, R. W., Kriz, G. J. and Bernal, R. (1973). Field evaluation of transient drain spacing equations. Trans ASAE., 16, 590-595.
 
Taylor G. S. (1960). Drainable porosity evaluation from outflow measurements and its use in drawdown equations. Soil. Sci., 90, 38-345.
 
Torabi M. (2014). Field Evaluation of drain spacing equations for Roodasht region of Esfahan. Water Res. Agri., 28(3), 635-644 [In Persian].
 
Upadhyaya A. and Chauhan H. S. (2000). An analytical solution for bi-level drainage design in the presence of evapotranspiration. J. Agri. Water Manag., 45(2), 169-184.
 
Yousef S. M., Ghaith M. A., Abdel Ghany M. B. and Soliman K. M. (2016). Evaluation and modification of some equations used in design of subsurface drainage systems. 19th International Water Technology Conference, Egypt.