华北地区百年气候变化规律分析

The Climate Change Features in the Last 100 Years

通过对比研究华北地区的范围，综合整理了相关华北地区的气温与降水变化规律，发现华北地区气温存在空间上由南向北降低，由沿海向内陆增高，再由内陆向山区降低；在时间上两个降温期两个升温期，即1880～1919年为第一个降温期（Ⅰj）；1920—1950年为第一个升温期（Ⅰs）；1951—1970年为第二个降温期（Ⅱj）；1971年至今为第二个升温期（Ⅱs）．并分析了气温地域性差异的主要原因是南北纬度的跨越、地形的非均一性和海陆位置的差异．而华北的夏季降水则存在空间上南部（东南部）降水多，北部（西北部）降水少，山区降水普遍多于平原，燕山南麓、胶东丘陵的南部沿海和鲁中山地的东南部均因地处夏季风的迎风坡，雨水集中，多暴雨，而背风坡、山间盆地则雨量较少；在时间上则可分为1880—1898年和1949—1964年的丰水期，1899～1947年和1965～1999年的枯水期．而影响华北夏季降水的原因可分为低纬和中纬地区海陆热力差异和北半球中高纬地区的大气环流异常．

By means of the contrast to the confines of North China, we integrate the climate change features of its air temperature and precipitation. The temperature reduces mainly from south to north, from coastland to mainland and from mainland to mountainous area in this area in the space. Because of the latitude span, the difference of landform and location, there are 4 periods in the last 100 years of temperature changes. The lower temperature phases appear during 1880 to1919, and 1951 to 1970. On the contrary, during 1920 to 1950, and 1971 to now, the temperature becomes rising. The precipitation also reduces mainly from south to north. And the mountainous areas have more rain water than the plain. By reason of the different heat of landform location and the unconventional circumfluence of atmosphere in the middle-high latitude, there are also 4 periods in the precipitation. The plenitude of precipitation appears from 1880 to 1898 and 1949 to 1964. And the Iow rain water appears from 1899 to 1947 and from 1965 to 1999.