Spatiotemporal Variation of Climate-induced Waterlogging for Winter Wheat in Jianghuai Region

【Background and objective】 Waterlogging is a natural disaster facing agricultural production in many countries across the world. Global warming is expected to increase its frequency. The objective of this paper is to analyze the spatiotemporal variation of climate-induced waterlogging for winter wheat in Jianghuai Region in central-southern China. 【Method】 The analysis was based on archived meteorological data measured from 143 weather stations across Anhui and Jiangsu provinces, from which we calculated the annual and monthly precipitation, potential evapotranspiration of the winter wheat. We divided the two provinces into a number of sub-regions based on climate and analyzed the data in each sub-region using the principal component analysis and K-means cluster methods. The spatiotemporal variation in waterlogging for each sub-region was calculated from daily standardized antecedent precipitation evapotranspiration index. 【Result】 ①From November to next February, long-lasting waterlogging was mostly likely to occur in the Jianghuai watershed and eastern Yangtze River, while from March to May, it was more likely to happen in the south and less likely in the north of the region. ②In west Yangtze River and in the high mountain areas, the occurrence of waterlogging in each 10 days increased as the crop grew from seedling to harvest, while in the Jianghuai watershed and east Yangtze River, the occurrence of waterlogging was independent of the growing season. In the north of the Huaihe River, the occurrence of waterlogging in the seedling stage was more frequent than in other growing stages. ③Intra-annual variation of waterlogging in each 10-day showed a significant increase from later November to middle of next February, and the variation coefficients was high. 【Conclusion】 Climate-induced waterlogging for winter wheat in Jiangsu and Anhui provinces is high but its occurrence varies spatiotemporally. These results are helpful for developing mitigating methods to alleviate the detrimental impact of waterlogging in the two provinces.