Regional changes of climate extremes and its effect on rice yield in Jiangsu province, southeast China

In this study, the regional variations of climate extremes and its possible impact on rice yield in Jiangsu province, southeast China were investigated. A total of 18 climate extremes indices (CEI) of rice-growing period (May-October) based on the daily climate records and rice yield data at 52 stations during 1961-2012 were calculated and analyzed. The main findings were as follows: (1) due to the remarked regional differences of climate extremes, Jiangsu could be divided into six climatic subregions: westernmost, northwest, north, southwest, south, and southeast corner; (2) trends of 18 indices in the six subregions using Mann-Kendall test indicated that Jiangsu was dominated by an obvious wetting and warming tendency, especially in the southern area; (3) correlation analysis between rice yield and CEI using first-difference and climate-induced yield method showed that the negative influences of precipitation extremes were more notable compared to temperature extremes; (4) P95 [precipitation due to very wet days (> 95th percentile)] should be selected as a key meteorological disasters indicator affecting rice yield in the northwest, north, southwest, and south Jiangsu; (5) the increase of P95 since 1990s was detected in most of Jiangsu, which would bring huge risks to rice growing.