关键词: 降水量, EOF, Mann-kendall突变性检验, 滑动T检验, 最大熵谱分析

Abstract: The time-spatial characteristics of precipitation in Hebei Province，China during 1961-2011 were analyzed by using Empirical Orthogonal Functions （EOF），Mann-kendall test，moving t-test，maximum entropy spectrum. The results showed that the spatial distribution of rainfall is very uneven and the greater precipitation lies on the side of the windward slope of Yanshan and Taihang Mountains. The large value center of precipitation which was greater than 600 mm lies on the southern Chengde，Tangshan，and Qinghuangdao. The precipitation had a downward trend in most area of Hebei. in addition to individual regions，the downward trend was not significant in most areas. The spatial distribution of annual precipitation in Hebei not only had the coherence in the whole area，but also showed variations from south to north. in time trend，the summer precipitation was decreased trend and the decreasing trend was anomaly significant. the increase （decrease） in May （August） was the most significant，but not significant changes in other momthly，seasonal，annual precipitation. there was a marked change among decades and years; there were abrupt changes and periods on annual and seasonal precipitation. The time-spatial distribution and variational characteristics conform with the terrain feature of Hebei and the variation discipline in large-scale climate system.

Key words: precipitation, EOF, Mann-kendall test, moving t-test, maximum entropy spectrum