近50年我国江淮流域气候变化

The Climate Change in the Yangtze-Huaihe River Valley over the Past 50 Years

为了详实地了解江淮流域的气候变化和进一步做好短期气候预测,利用近50a气温和降水资料,从平均值和变率两方面研究了我国江淮流域的气候变化。结果表明:(1)近50a来江淮流域气候变化的主要特征是气候变暖,与全国变暖的趋势一致;降水呈不显著的增长趋势。温度和降水由低基本态向高基本态过渡,目前均处于高气候基本态下;(2)无论是温度还是降水,其变率随时间而变,目前均处于高气候变率时段,要注意高基本态和高变率结合易导致的高温、洪涝等极端气候事件;(3)温度在1986年前后发生了一次突变,降水在1968年前后发生了一次突变。无论是温度还是降水,突变后均比突变前有所增加。根据突变分析可将江淮流域近50a气候变化过程划分为相对冷干阶段(20世纪50～60年代)—相对冷湿阶段(70～80年代)—相对暖湿阶段(90年代至今)。

Using the data for the temperature and precipitation during the past 50 year, the climate change in the Yangtze-Huaihe River Valley is analyzed. The results indicate that (1) Warming is the most primary mode of climate change, especially in winter. The precipitation also increased. Both climate base states of temperature and precipitation vary from low to high in the past 50 years. (2) Climate variability also varies with time, and at present both temperature and precipitation are in a phase of high base state and high climate variability so that we should be aware of frequent occurrences of extreme climate events. (3) There is an obvious climate jump due to temperature and precipitation respectively. The jump point of temperature happened in 1986 and that of precipitation happened in 1968. After the jumps both the mean annual temperature and the mean annual precipitation increased. According to abrupt change analysis, we can divide the past 50 years into three phases, i.e. the cold-dry phase (1950s～1960s), cold-wet phase (1970s～1980s) and warm-wet phase (since 1990s).