THE DRAINMOD SIMULATION MODEL APPLIED TO A SUBSURFACE DRAINAGE SYSTEM IN LA CHONTALPA, TABASCO

Abstract

The water management simulation model Drainmod was evaluated in a field plot planted with a chili (Capsicum annum L.) crop in which a system of subsurface drainage at five drain spacings was already established in the region of La Chontalpa, State of Tabasco. The model was calibrated by adjusting the hydraulic conductivity (K) value until good agreement between the calculated and the measured water table depths was reached. For the model validation, a data subset, not used for calibration, was considered. In general, a better association between the measured data and the predicted values was found for soils with high K than for soils with low K. The parameters of evaluation of the system: work days, humid days, dry days and relative yield were not significant. It was concluded that this model could be used as a tool for planning drainage systems in the humid tropic of southeast México, provided that the model is previously calibrated.