Synthetical Intensity Characteristica of Interdecadal Extreme Air Temperature and Precipitation Events in Heilongjiang Province from 1967 to 2007
黑龙江省1967年至2007年极端气温与降水综合强度的时空特征分析

The discussion of interdecadal and distribution characteristics of synthetical intensity for extreme air temperature and precipitation events is important to the ecological environment, and disaster prevention and reduction. With daily air temperature and precipitation data from 73 meteorological stations from 1967-2007 in Heilongjiang Province, based on the synthetical intensity model method of extreme climatic events, the synthetical intensity characteristics of interdecadal and distribution for extreme air temperature and precipitation events were analyzed in Heilongjiang Province. We found that the synthetical intensity trends of interdecadal variability of extreme high temperature generally increased in summer and autumn. The increased trend of synthetical intensity was more prominent especially after the 1990s; the increased trend was most prominent for the Songnen plain. Synthetical intensity trends of interdecadal variability of extreme low temperature events generally decreased in spring and winter; the decreased trend was more prominent in winter, the extreme low temperature events of the Sanjiang plain and Songnen plain in spring and winter after 1995 are also worth noting. Synthetical intensity trends of interdecadal variability of extreme precipitation events decreased in spring and autumn, and increased in summer and winter; the decreased trend was more prominent in autumn and the increased trend was most prominent in winter. Synthetical intensity increased markedly in the beginning of spring (Sanjiang plain and Songnen plain) and winter (three typical areas) after the 21th century, snow disasters were more frequent. Synthetical intensity of three typical areas were decreased markedly in summer and autumn after the 21th century, water resources were often short and the warm dry climate trend of Songnen plain could be increased. The most impacted regions of synthetical intensity of extreme high temperature events in distribution were in the western Songnen plain, Sanjiang plain in summer and autumn in Heilongjiang. The extreme low temperature events in distribution were Sanjiang plain, the north of Mudanjiang region, and the north-west of Harbin in spring and winter. The most impacted regions of the synthetical intensity of extreme precipitation events in distribution were Mohe county northest of the Daxingan Mountains, Xiaoxingan Mountains, east of the Sanjiang plain, and the semi-mountainous area of Mudanjiang region. The distribution characteristics were different in every season, the distribution of the synthetical intensity was increased from the west to the east in spring and autumn and the synthetical intensity was stronger in middle regions in summer.