Subsurface Drainage Cost and Hydrologic Model

A computer simulation water balance model was used to analyze the variation of daily water-table depths in the field using 27 yrs of weather data and soil water parameters. The high water table in the study area resulted from a cool moist climate and poor natural drainage condition. The effects of drainage rates and drain depths on the water table were studied. A frequency analysis was done to obtain the recurrence intervals of specific water-table depths for various successive number of days. The net financial benefit from the system was evaluated corresponding to various chances of crop failure due to inadequacy of the drainage system during its assumed amortization period.