Abstract:
Under the background of global warming, recently meteorological disasters and their evocable socioeconomic losses have risen, since the extreme weather and climate events occurred frequently. For disaster prevention and reduction, it has guiding significance to deeply understand the characteristics of extreme air temperature and precipitation events which are closely related to the social life. This paper calculated the probability density values of extreme daily air temperature and precipitation through their percentile thresholds, and, based on the probability distribution of extreme values, the hierarchical clustering method was used to incorporate stations. Then the number of regions for the extreme meteorological elements in China was determined according to the stability of variation, and the serial numbers for the various regions were determined by their most probable daily temperature means and precipitation means. The temporal variation and characteristics of the probability distribution of the representative stations that were chosen according to their maximum similarity coefficient to the stations in the same region, were analysed. The analyses show that the spatial distributions of extreme minimum air temperature (except for summer), extreme maximum air temperature in winter, as well as daily precipitation in winter and spring are similar to the distributions of their annual climatic average values, which shows fair relationship with latitude and altitude, that is, latitude and altitude have the greatest influence on the spatial distribution pattern of extrema in spring and winter, respectively, whereas both have great influence in other two seasons; and the spatial difference of the extreme high/low values is mostly determined by altitude/latitude. It is also shown that extreme air temperature events more likely occur in spring and autumn; serious extreme high and low-temperature events more likely occur in spring and winter over the northern part of China, and serious extreme hightemperature and precipitation events more likely occur in summer over the southeast of China. Compared between the extreme values of the two different climate states, in recent 30 years daily temperature has obviously risen in winter. And the first and second greatest increase in daily precipitation occurs in autumn and summer. The increase in the extremeness and probabilities of lowtemperature events in four seasons (especially in winter) are obvious. And the probabilities of extreme maximum temperature in autumn and winter and extreme precipitation in winter are all increased. The increase in the extremeness of extreme precipitation events in four seasons occurs as well. At the end of this paper, some suggestions of disaster prevention and reduction for the regions where serious extreme temperature and precipitation events more likely occurred were provided.