Simulation of 2D Soil Moisture Distribution under Subsurface Drip Iirrigation

Document Type : Research Paper


1 Ph.D. Candidate, Tarbiat Modarres University

2 Associate Professor, Irrigation and Drainage Engineering Department, Tarbiat Modarres University

3 Associate Professor, Irrigation and Reclamation Engineering Department, University of Tehran

4 Professor, Department of Soil Science, Tarbiat Modarres University

5 Professor, Agricultural Engineering Research Institute, Ministry of Jahad-e-Keshavarsi


Information on water soil content and its distribution is vital for field water management in subsurface irrigation. The objective followed in this study was to simulate the extent of wastewater distribution taking into account root water uptake and evaporation from the soil surface under, subsurface drip irrigation system. In this regard, a field experiment was conducted with lettuce as the crop, to collect the required data. Soil hydraulic properties were obtained through an assessment of in-situ soil water pressure heads as well as water contents. Soil matric potentials, under tensiometery range, were obtained by use of tensiometers and the related water contents by a TDR instrument. For the simulation purposes, the HYDRUS-2D model was made use of. The model performance was evaluated by comparing the measured us the predicted values using Root Mean Square Error (RMSE) statistics. The results of the spatial simulation revealed that this model provides more appropriate results in locations farther away, and deeper than The  drippers (RMSE=0.03) as compared with the points  adjacent to the droppers and less deeper ones (RMSE=0.008). The results of the temporal simulation showed that the model worked more accurately within 48 hrs after irrigation (RMSE=0.005) rather than one following the start of irrigation (RMSE=0.029). Therefore, it can be concluded that soil water content in subsurface drip irrigation system can be reasonably simulated while root water uptake and evaporation processes are both actively going on.


Main Subjects

Abbasi, F., Jacques, D., Simunek, J., Feyen, J., and van Genuchten, M. Th. (2003a). Inverse estimation of soil hydraulic and solute transport parameters from transient field experiments: Heterogeneous soil. Transactions of the ASAE, 46(4), 1097-1111.
Abbasi, F., Simunek, J., Feyen, J., Van Genuchten, M. Th., and Shouse, P. J. (2003b). Simultaneous inverse estimation of soil hydraulic and solute transport parameters from transient field experiments: Homogeneous soil. Transactions of the ASAE, 46(4), 1085-1095.
Arkin, G. F. and Taylor, H. M. (1981). Modifying the root environment to reduce crop stress. American Society of Agricultural Engineers.
Ben-Gal, A., Lazorovitch, N., and Shani, U. (2004). Subsurface drip irrigation in gravel-filled cavities. Vadose Zone Journal, 3(4), 1407-1413
Besharat, S., Nazemi, A. H., Sadraddini, A. A., and Shahmorad , S. (2012). Applications of HYDRUS and the Proposed SWMRUM Software inSimulatingWater Flow with RootWater Uptake Through Soils, Water and soil science, Vol. 21, No.4. (In Farsi)
Brouwer, C. and Heibloem, M. (1986). Irrigation water management: Irrigation water needs. Training manual, 3.
Feddes, R. A., Kowalik, P. J., and Zaradny, H. (1978). Simulation of Field Water Use and Crop Yield, John Wiley & Sons, New York, NY.
Gardenas, A. I., Hopmans, J. W., Hanson, B. R., and Simunek, J. (2005). Two-dimensional modeling of nitrate leaching forvarious fertigation scenarios under micro-irrigation, Agricultural Water Management 74: 219-242.
Homaee, M., Dirksen, C., and Feddes, R. A. (2002a). Simulation of root water uptake: I. Non-uniform transient salinity using different macroscopic reduction functions. Agricultural Water Management, 57(2), 89-109.
Homaee, M., Feddes, R. A., and Dirksen, C. (2002b). Simulation of root water uptake: II. Non-uniform transient water stress using different reduction functions. Agricultural water management, 57(2), 111-126.
Homaee, M., Feddes, R. A., and Dirksen, C. (2002c). Simulation of root water uptake: III. Non-uniform transient combined salinity and water stress. Agricultural water management, 57(2), 127-144.
Kandelous, M. and Simunek, J. (2010a). Comparison of numerical, analytical, and empirical models to estimate wetting patterns for surface and subsurface drip irrigation. Irrigation Science, 28(5), 435-444
Kandelous, M. and Simunek, J. (2010b). Numerical simulations of water movement in a subsurfacedrip irrigation system under field and laboratory conditions using HYDRUS-2D. Agricultural Water Management, 97(7), 1070-1076.
Li, J. and Liu, Y. (2011). Water and nitrate distributions as affected by layered-textural soil and buried dripline depth under subsurface drip fertigation. Irrigation Science, 29(6), 469-478.
Patel, N. and Rajput, T. B. S. (2007). Effect of drip tape placement depth and irrigation level on yield of potato. Agricultural water management, 88(1), 209-223.
Provenzano, G. (2007). Using HYDRUS-2D simulation model to evaluate wetted soil volume in subsurface drip irrigation systems. Journal of Irrigation and Drainage Engineering, 133(4), 342-349.
Ritchie, J. T. (1972). Model for predicting evaporation from a row crop with incomplete cover. Water resources research, 8(5), 1204-1213.
Simunek, J., Sejna, M., and van Genuchten, M. Th. (1999). The Hydrus2D Software Package for Simulating Two-Dimensional Movement of Water, Heat, and Multiple Solutes in Variable Saturated Media. Version 2.0.IGWMC-TPS-53, International Ground Water Modeling Center, Colorado School of Mines, Golden, Colorado,pp. 1-251.
Singh, D. K., Rajput, T. B. S, Sikarwar, H. S., Sahoo, R. N., and Ahmad, T. (2006). Simulation of soil wetting pattern with subsurface drip irrigation from line source. Agricultural water management, 83(1), 1. 30-134.
Skaggs, T. H., Trout, T. J., Simunek, J., and Shouse, P. J. (2004). Comparison of HYDRUS-2D simulations of drip irrigation with experimental observations. Journal of irrigation and drainage engineering, 130(4), 304-310.
Thompson, T. L. and Doerge, T. A. (1995). Nitrogen and water rates for subsurface trickle-irrigated romaine lettuce. HortScience, 30(6), 1233-1237.
Vrugt J. A., Hopmans, J. W., and Simunek, J. (2001). Calibration of a two-dimensional root water uptake model. SoilSc. Soc. Am. J. 65: 1027-1037.
Wang, J., Gong, S., Xu, D., Juan, S., and Mu, J. (2013). Numerical simulations and validation of water flow and heat transport in a subsurface drip irrigation system using hdrus-2D., Irrigation and Drainage, 62: 97-106.
Zarei, G., Homaee, M., Liaghat, A. M., and Hoorfar, A. H. (2010). A model for soil surface evaporation based on Campbell’s retention curve. Journal of hydrology,380(3), 356-361.‏