1961—2010年中国东北半干旱区东界变化趋势分析

Trend of the Eastern Boundary of Semiarid Zone in Northeast China in 1961-2010

气候带边界的变化是大尺度地理特征对气候变化的响应方式之一,半干旱区的边界变化对其响应尤为敏感。我们整合了中国东北地区50年(1961—2010年)的气象数据,以降水量和温度所计算的干燥度指数作为干湿气候带划分的指标,在ArcGIS中采用Kriging空间插值法,在不同时间尺度上分析了近50年来中国东北半干旱区东界的波动趋势。结果表明:中国东北半干旱区界限变化呈整体向东、向南扩展的趋势,其变化受时间累积效应的影响,在50年(1961—2010年)尺度上范围最大,面积为285 648.4km2。数据分析表明,降水量减少是导致半干旱区边界变化的主要因素,气温的影响次之。

The boundary variation of climatic zone is one of the sensitive indicators to climate change at large geographical scale, especially for semiarid zone. Aridity index, which is calculated with precipitation and temperature data as division index, had been analyzed by using Kriging spatial interpolation method based on meteorological data in recent decades of Northeast China in 1961--2010. In addition, different temporal scales had been used to analyze the fluctuation trend of the eastern boundary of semiarid zone in Northeast China. Results showed that the eastern boundary of semiarid zone in Northeast China had expanded to east and south generally, the variation was mainly affected by temporal accumulative effects. In fifty-year scale, the zone reached as large as 285 648.4 km2. Analysis also indicated that precipitation decrease was a main driving factor on the variation of the eastern boundary of semiarid zone in northeastern China, and the temperature increase was another main factor.