Trend analysis of temperature and precipitation extremes in major grain producing area of China

摘要

To identify whether the spatial and temporal distribution of temperature extremes and precipitation extremes has changed in central and eastern China including Henan, Shandong, Anhui and Jiangsu provinces, the spatial and temporal distributions of extreme temperature and precipitation indices trends during 1961-2011 were investigated and analysed. To guarantee the accuracy of trend analysis, daily maximum and minimum surface temperature and daily precipitation from 299 meteorological stations were used. Eight extreme temperature indices and seven extreme precipitation indices were chosen. Mann-Kendall method was used to check the statistical significance of trends, while Sen's nonparametric method was used to calculate the trend magnitudes. The analyses of extreme temperature indices detected significant and stable trends in the majority of the stations, especially for the most part of southern Anhui and southern Jiangsu provinces. The strongly stable downward trends in cold extremes and the strongly stable upward trends in hot extremes were recorded in most of the regions. In contrast, significant and stable positive trends were insignificantly recorded for precipitation extremes in the study area, which predominantly occurred in the southern part of the region. Furthermore, the positive trends were more frequent than the negative trends in most extreme precipitation indices. The results may provide a reference for a more particular knowledge of the climate change in this region and provide guidance for agriculture development.