东北地区降水年内分配的不均匀性

Intra-annual inhomogeneity characteristics of precipitation in Northeast China

利用东北地区93个台站1961-2005年的逐日降水资料,通过降水集中度和降水集中期,讨论了该地区降水的年内分配不均匀分布特征。结果表明,东北地区的降水集中度自东南向西北逐渐递减;集中期具有南北高中间低的变化特点。从长期趋势上看,降水集中度的减小趋势显著,在该地区的东北部和西北部各有一个趋势明显的区域(通过0.05的显著性检验),但集中期的减小趋势不显著,只有2个台站通过显著性检验。年降水量与降水集中度和降水集中期的相关系数表明:东北地区年降水量与降水集中度呈显著的正相关,即年降水量越多(少)的地区,年内降水越集中(均匀);年降水量与降水集中期的关系并不显著。

Based on the daily precipitation data at 93 stations in Northeast China from 1961 to 2005, the features of precipitation were analyzed by using the definitions of precipitation concentration degree （PCD） and precipitation concentration period （PCP） . The results show that the PCD decreases gradually from southeast to northwest and the PCP has the character of high value in north and south, and low value in middle. In view of the long-term change, the PCD displays an obvious decreasing trend, especially in the northeast and northwest （through 0.05 significance examination） , but the change of PCP is not obvious, only two stations satisfy 0.05 significance examination. It is also found that the annual amount of precipitation has significant positive correlation with PCD, and has a slightly correlation with PCP, that is to say the much （less） is the annual precipitation, the bigger （smaller） is the PCD.