Simulation of Farmland Groundwater Table Depth and Soil Salinity under Drainage Systems in Tidal Areas, Laizhou Bay of China

Abstract

AbstractDRAINMOD‐S was evaluated using field data from Laizhou Bay, a tidal area in China, for two cropping seasons. Subsurface and conventional drainage were applied in the study area. The DRAINMOD‐S model was calibrated and validated by comparing the observed and predicted values of groundwater table depth drainage discharge and soil salinity. The calibration and validation results were satisfactory with the mean relative error (MSE) less than 10%, Nash–Sutcliffe efficiency (NSE) higher than 0.70 and coefficient of determination (R2) higher than 0.75. The impacts of both subsurface and conventional drainage treatments on groundwater table depth, drainage discharge and soil salinity in 2015–2045 were evaluated with the future climate data provided by the IPCC. Seasonal variations of groundwater table depth and soil salinity were observed under both drainage treatments. The subsurface drainage practice was more suitable for the studied area, with groundwater table depth effectively controlled in the rainy seasons and soil salinity under the crop salt tolerance threshold during most of the predicted periods. This study will highlight the efforts and implementation of drainage management practices to promote sustainable development of agricultural systems in tidal areas under climate change conditions. Copyright © 2017 John Wiley & Sons, Ltd.