1961—2017年华北地区降水气候特征分析

基于华北地区1961—2017年的均一化降水数据,从降水量、降水强度、降水日数和降水量贡献率等方面揭示了华北地区降水的气候特征。结果表明:1961—2017年华北地区年降水量以3.2 mm/10a的速率减少,其主要原因是夏季降水的减少。空间上,降水量大值区的降水趋势变化呈减少特征;降水强度呈增大趋势,降水的时间分布更加集中;小雨、暴雨和大暴雨及以上量级降水日数和贡献率呈减小趋势,而中雨和大雨则有所增加;分析各等级降水对华北地区空间分布的贡献率,小雨事件对华北地区西部降水的贡献最主要,大雨、暴雨和大暴雨对华北东南部地区降水量的贡献最为主要,这进一步解释了小雨、暴雨和大暴雨及以上量级降水量的减少造成了华北地区西部和东南部地区降水总量的下降。华北地区降水气候特征研究可为区域气候变化以及暴雨、干旱等灾害应对提供科学支撑。

Climatic Characteristics of Precipitation in North China from 1961 to 2017

The climatic characteristics of precipitation in North China were reflected from the aspects of precipitation, precipitation intensity, precipitation days and precipitation contribution rate based on the homogenized precipitation data of 84 meteorological stations from 1961 to 2017 in North China. The results showed that the annual precipitation in North China decreased at a rate of 3.2 mm/10a from 1961 to 2017, which was mainly due to the decrease of summer precipitation, on the contrary, the precipitation in winter, spring and autumn increased. The trend of precipitation in the area with high precipitation value was decreasing, while that in the central and western regions and the northeast showed a weak increasing trend. The precipitation intensity showed an increasing trend, reaching the maximum in the 1990s and the 21st century (2011-2017), and the precipitation intensity in most areas had increased. The number of days and contribution rate of light rain, storm rain and heavy storm rain were decreasing, while those of moderate rain and heavy rain were increasing. The areas with decreasing precipitation days were mainly concentrated in Beijing-Tianjin-Hebei-Shanxi region, which were 34-42° N and 110-120° E. By analyzed the contribution rate of different levels of precipitation to the spatial distribution of North China, we could knew that the contribution of light rain to the precipitation in the western part of North China was the most important, and the contribution of heavy rain, storm rain and heavy storm rain to the precipitation in the southeast part of North China was the most important, which further explained the fact that the decrease of light rain, storm rain and heavy storm rain and the precipitation of above magnitude resulted in the decrease of the total precipitation in the western and southeast part of North China. The research on the characteristics of precipitation climate in North China can provide scientific support for regional climate change, rainstorm, drought and other disasters.