Spatiotemporal Characteristics of Winter Wheat Waterlogging in the Middle and Lower Reaches of the Yangtze River, China

The waterlogging is a serious agrometeorological disaster caused by excessive soil water during crop growth stages. The middle and lower reaches of the Yangtze River are one of the major winter wheat growing regions in China and at the same time they are waterlogging-prone due to their specific climatic conditions. In this study, we integrated a set of tools to analyze the spatiotemporal features of winter wheat waterlogging in this region. We proposed a waterlogging precipitation index (WPI) based on winter wheat yield loss rate and precipitation anomaly percentage and analyzed the frequency, scope, and intensity of winter wheat waterlogging. The results showed that the spring rainfall had a direct and significant effect on winter wheat yield, and the meteorological yield of winter wheat was negatively correlated with precipitation abnormal event from jointing to maturity stages (March to May) across the whole study area. The matching between the waterlogging severity identified by the WPI and historical winter wheat waterlogging records was relatively high. We also discussed the influences of the other nonmeteorological factors, for example, soil texture, topographic and geomorphic conditions, and local disaster-resisting ability, on the extent of waterlogging damage.