Water Management Model Evaluation for North Central Ohio

ABSTRACT DATA from a field drainage experiment in North Central Ohio were used to evaluate the reliability of the water management simulation model, DRAINMOD. Predicted and measured outflow volumes were compared for field plots with surface drainage alone, subsurface drainage alone and for combination plots with both sur-face and subsurface drainage. Comparisons were made for four replications of each treatment over a total of eight years. Inputs to the model were climatological, crop, soil property and drainage system parameter data for each treatment. Predicted and measured surface runoff and drainage volumes were in good agreement for all treatments. Devi-ations in predicted and measured volumes for individual drainage events were usually small and, in most cases, about the same magnitude as measured differences be-tween replications.