近51年呼伦贝尔市暴雨日数的时空分布特征

为了研究呼伦贝尔市暴雨日数的时空分布特征，防范暴雨引发的洪涝灾害对农业产生的影响，利用呼伦贝尔市地区16个气象站1960—2010年逐日降水资料，采用线性趋势分析和Mann-Kendall突变检验方法，分析呼伦贝尔市近51年暴雨日数的时空分布。结果表明：该地区暴雨日数具有明显的年代际变化，总体方向呈减少趋势；暴雨的发生具有明显的季节分布特征，暴雨开始于春季5月，结束于秋季9月，且主要出现在夏季，并且集中在7月末和8月初；暴雨空间分布具有明显的地域性，各站暴雨日数和暴雨雨量极值均出现在松嫩平原与大兴安岭山脉东南过渡的山坡上，说明呼伦贝尔市暴雨受地形影响明显；暴雨日数突变减少时刻发生在1997年，突变后暴雨日数减少趋势显著。

Spatial and Temporal Distribution of Rainstorm Days in Hunlun Buir in the Last 51 Years

In order to study the spatial and temporal distribution of rainstorm days in Hunlun Buir and to guard against the impact on agriculture from flood disasters caused by rainstorm, the daily precipitation data from 16 meterological stations in Hunlun Buir Area during 1960 to 2010, through linear trend analysis and Mann- Kendall catastrophe test, composite analysis were analyzed in the spatial and temporal distribution characteristics and their variation of rainstorm days in Hunlun Buir Area. The results showed that： rainstorm days tendsed to be less in recent 51 years; heavy rain in this area was obviously distributed by seasons, the heavy rain started in May of spring and ended in September of fall, most of the heavy rain were in summer, especially concentrated in late July and early August. Rainstorm in this area was also obviously distributed by regions, and most of the heavy rain was on the hillside between the southeastern of Daxing ＇ an Mountains and the Songnen Plain. The abrupt change of rainstorm happened in 1997, the rainstorm clays had a trend of quickly reduced after abruption.