Evaluation of COUP Model Simulation of Soil Moisture and Temperature under Maize Canopy and Bare Soil

Document Type : Research Paper

Authors

1 Former M.Sc. Student of Agrometeorology, University of Tehran

2 Assistant Professor, University of Tehran

3 Associate Professor, Institute of Geophysics, University of Tehran

Abstract

Because of the scarcity of in situ measurements, simulations of soil moisture and temperature are very important for irrigation management and scheduling and evapotranspiration estimation in different field conditions. This paper aims at evaluating the efficiency of the COUP model in simulating soil temperature and moisture dynamics in two plots under maize canopy and with no vegetation cover in Karaj climate. Soil physical parameters, estimated based on the soil analysis (soil texture, bulk density), and daily meteorological parameters (including maximum and minimum temperature, wind speed, pan evaporation, sunshine hours and rainfall) and cropdata (crop height, root depth, and leaf area index) were used to run the model over the growing period. Soil temperature was measured using standard soil thermometers at depths of 10, 30, 50 and 70 cm and soil moisture was measured by means of a theta probe installed at the same depths. Statistical criteria were used to compare the simulated soil temperature and moisture with those observed.  Results showed that the COUP model was highly efficient in simulating soil temperature. The simulated soil moisture was comparable with observations. However, the model was less skillful in simulating soil moisture than temperature. Further scrutiny is needed to assess the possible reasons for this discrepancy. 

Keywords

References

  1. Ahrens, C. D. 2000. Essentials of Meteorology – An Invitation to the Atmosphere (Third Edition). Brooks/Cole Publishers.
  2. Brooks, R. H. and Corey, A. T., 1964. Hydraulic properties of porous media. Hydrology Paper No. 3, Colorado State University, Fort Collins, Colorado, 27 pp.
  3. Eckersten, H., Jansson, P.E., and Johnsson, H., 1998. SOILN Model, Version 9.2, User’s Manual. Division of Hydromechanics, Communication 98:6. Swedish Agricultural University, Uppsala.
  4. Fischer, R. D. 1982. Models of simultaneous heat and moisture. Battelle Columbus Labs, 2.Transfer in soils, ORNL-Sub, 80-7800-1&06 October 1983.
  5. Flerchinger, G.N., Hanson, C.L. and Wight, J.R.   Modeling evapotranspiration and surface energy budgets across a watershed.  Water Resour. Res., 32(8):2539-2548.
  6. Ghahreman, N. and Hundal, S. S., 2006. Modeling soil water contents, potato growth and yield with SWACROP model in Punjab, India. J. Agrometeorology. 6(2): 21-27.
  7. Irannejad, P. and Shao, Y. 1998. Description and validation of the atmosphere–land–surface interaction scheme (ALSIS) with HAPEX and Cabauw data. Global and Planetary Change. 19: 87-114.
  8. Irannejad, P. and Shao, Y., 2002. Land-surface Processes, in: Peng, G., Leslie, L.M. and Shao, Y. (eds), Environmental Modeling and Prediction. Springer-Verlag Germany, 173-213.
  9. Irannejad, P., Shao, Y. and Findlater, P. A., 1997. The Impact of Vegetation Cover on Soil Water Balance, a Model Simulation, in: Munro, R. K. and Leslie, L. M. (eds), Climate Prediction for Agricultural and Resource Management, BRS, Canberra, 165-184.
  10. Jansson, P.-E. and Karlberg L., 2005. Coupled heat and mass transfer model for Soil-Plant-Atmosphere Systems. Royal Institute of Technology, Department of Civil and Environmental Engineering, Stockholm, pp 453.
  11. Jansson, P.-E., 1998. Simulating model for soil water and heat conditions, Division of Hydromechanics, Communication 98:2. Swedish University of Agricultural Science, Uppsala, Sweden.
  12. Jansson, P.-E., 2005.  Simulation of soil temperature and moisture dynamics for different rainfall conditions in northeast China. Proceedings of the 3rd International Symposium on Intelligent Information Technology in Agriculture (ISIITA), Part Three Agriculture System Simulation, 293-296.
  13. Jansson, P.-E., and Moon, D.S., 2001. A coupled model of water, heat and mass transfer using object orientation to improve flexibility and functionality. Environ. Modeling and Software, 16:37-46.
  14. Jansson, P-E. and Haldin, S., 1979. Model for the annual water and energy flow in a layered soil. In: S. Haldin (ed.) Comparison of forest and energy exchange models. Society for Ecological Modeling, Copenhagen, 145-163.
  15. Johnsson, H. and Jansson, P.-E., 1991. Water balance and soil moisture dynamics of field plots with barley and grass ley. J. Hydrology., 173: 129-149.
  16. Mualem, Y., 1976. A new model for predicting the hydraulic conductivity of unsaturated porous media. Water Resour. Res. 12:513‑522.
  17. Philip, J. R., and de Vries, D. A., 1957. Moisture movement in porous materials under temperature gradients, Trans. American Geophysical Union, 38: 222-232.
  18. Schaap, M. G., Leij, F. J. and Van Genuchten, M. Th., 2001. ROSETTA: A computer program for estimating soil hydraulic parameters with hierarchical pedotransfer function. J Hydrol., 251: 163-176.
  19. Shaw R.H. and Pereira, A.R., 1982. Aerodynamic roughness of a plant canopy: a numerical experiment. Agricultural Forest Meteorology, 26: 51-65.
  20. Thunholm, B. 1990. A comparison of measured and simulated soil temperature using air temperature and soil surface energy balance as boundary conditions. Agricultural and Forest Meteorology, 53:59‑72.
  21. Van Genuchten, M. Th., 1980. A closed-form equation for predicting the hydraulic conductivity of unsaturated soils. Soil Sci. Soc. Am. J. 44:892-898.
  22. Willmot, C.J., 1982. Some comments on the evaluation of model performance. Bul. Amer. Meteorl. Soc., 63:1309-1313.
Iranian Journal of Soil Research
Volume 26, Issue 1
June 2012
Pages 55-66

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