Recent changes of extreme dryness/wetness pattern and its possible impact on rice productivity in Jiangsu Province, southeast China

Based on the data of monthly precipitation and rice productivity at 61 meteorological stations in Jiangsu during 1966–2010, the possible impact of dryness/wetness variability on rice productivity was explored in this paper. Principal component analysis was applied to the climate-induced rice productivity index (CRPI) series and divided Jiangsu into six sub-regions—south, northwest, east, middle, southwest and northernmost. Mann–Kendall trend test for monthly Standardized Precipitation Index (SPI) series in each sub-regions shows that most of Jiangsu was dominated by wetter tendency in August and drier tendency in September. CRPI had stronger negative correlation with monthly SPI series in the majority of sub-regions. Especially, the SPI in October, March, July and August had significantly negative linear relationship with CRPI in south Jiangsu, northwest Jiangsu, middle Jiangsu and southwest Jiangsu, respectively, which indicated the obvious unfavourable impact of extreme wetness episodes on rice productivity.