Simulation and Analysis of Water Table and Drainage Discharge under Controlled Drainage in a Field Experiment Using DRAINMOD Model

A field experimental project was carried out in Jingzhou City, Hubei Province to research the effects of controlled drainage on groundwater table and drainage discharge. And used DRAINMOD model to simulate the designed experiment schemes. The results showed that the numerical results of the groundwater table from DRAINDOD model were quite similar to the practically measured results during cotton growth period, the correlation coefficients were more than 0.9, the simulation results are in line with the experiment results. The underground drainage discharge of each plot was passively correlated with controlled water level, while the surface drainage discharge was positively with it. The underground drainage discharge was larger than the surface. The total drainage discharge was also passively correlated with the controlled water level. The DRAINMOD model can provide good estimates of the groundwater table and the drainage discharge under controlled drainage.