东北地区是中国重要的粮食作物和经济作物的生产基地,作为气候变化的敏感地区之一,在气候变化背景下,易受异常降水、干旱等事件的影响。为了研究东北地区近50年来(1961 2014年)降水量变化的空间分区及其区域特征,利用该区87个气象站1961 2014年逐月降水资料,计算各站的降水距平百分率,通过旋转经验正交函数(REOF)分解,对该区降水量变化特征进行分区,并结合分区结果,采用线性趋势分析及5年滑动平均分析方法,分析了全区及各个分区1961 2014年的降水量变化特征。结果表明:东北地区降水量变化分成4个区域,即东南部地区、中部偏西地区、北部地区和西南部地区;东北地区的年降水量距平具有较小的下降趋势,气候倾向率为-4.817 mm ? 10 a~(-1);各区域与全区降水量变化趋势基本相同,均为降水量趋于减少,减少趋势最大的是西南部地区,气候倾向率为-7.699 mm ? 10 a~(-1),最小的是北部地区,气候倾向率为-0.798 mm ? 10 a~(-1)。
英文摘要:
Northeast China is an important base for food and cash crop production. As one of the sensitive areas to climate change,Northeast China is susceptible to abnormal rainfall,drought and other extreme events under the background of climate change. In order to study the division of precipitation change and its regional characteristics in Northeast China, the monthly precipitation data during 1961-2014 from 87 meteorological stations were used to calculate the percentage of precipitation anomalies,the division of precipitation change was made by using rotated empirical orthogonal function analysis (REOF) method,and the variation trends of precipitation in the whole area and each division region during 1961 -2014 were analyzed by using linear trend analysis and 5-year moving average analysis method. The results showed that Northeast China could be divided into 4 regions including southeast, central west, north and southwest regions. The annual precipitation anomalies in Northeast China had a slight decline trend, and the climatic trend rate was -4.817 mm ? 10 a~(-1). Each region exhibited a similar decline trend with the whole area. The most obvious decline occurred in southwest region, while the least decline was in north region, with the climatic trend rates of -7.699 and -0.798 mm ? 10 a~(-1),respectively.