Simulating the impact of flooding on wheat yield - Case study in East China

In order to account for the waterlogging damage to crop yield, a process-based regional crop model for wheat was modified to represent surface hydrology and the waterlogging stress. Two schemes of differing complexity were investigated, the first a simple generic scheme that could be easily modified for other crops, while the second approach requires detailed field studies to measure an array of required parameters for each crop growth stage. Using simulations of wheat yield in south-east China as a test case, both waterlogging schemes can capture the yield reduction in wet years such as in 1991 and 1998. Although the more complex waterlogging scheme gives the highest correlations with observed wheat yield, the difference to the simple scheme is marginal, and much smaller than the improvement relative to the default model in which waterlogging is neglected. Thus for areas subject to intense rainfall, even adding a simple scheme can capture the zero-order impact of waterlogging and improve yield simulations significantly.