A WCSODS-BASED MODEL FOR SIMULATINGWET DAMAGE FOR WINTER WHEAT IN THE MIDDLE AND LOWER REACHES OF THE YANGTSE RIVER

The correction models of the effect of excess soil water on photosynthetic production, partition of dry matter and green leaf senescence are introduced into the WCSODS to simulate the impacts of soil waterlogging on wheat growth. The modules are validated with experimental data and regional statistical yields, and the results show that the simulated errors are less than 10%. The sensitivity analysis also shows that the wet damage to yield increases gradually with the increasing waterlogging duration. Ten-day waterlogging has little effect on yields, but when the waterlogging duration reaches 30 days, yields reduce 7% to 32%. For the same waterlogging duration, the injury at the booting stage is the greatest, less at filling stage and elongation stage, and the least at tillering stage. These results are in accordance with the opinions of local wheat experts. The early warning of wet damage is also conducted and tested by using the model and the daily meteorological and yield data, and the results are reasonable.