Evaluation of DRAINMOD for estimation of water table and drainage rate (case study: drainage system of Behshahr RAN company)

This study was carried out in a Behshahr RAN company field in order to evaluateDRAINMOD model. Water table levels at the midpoint and drain water effluents weremeasured during three months of rainfall period (autumn, 2004). Model validation wasperformed by comparing simulated and measured data collected from water table anddrainage rate. Mean Absolute Error (MAE), Standard Error (SE), and Coefficient ofDetermination (R2) were estimated for water tables which were 14.4 cm, 16.7 cm and0.89, respectively; and the parameters for drainage rate were 0.42 mm/day, 0.65 mm/day,and 0.78, respectively. The accuracy of the model for the estimation of the water tablewas more than that for the drainage rate. The results of this study indicate that theDRAINMOD model can be useful for long term simulation and water table managementin moderate climatic condition of Iran.