我国北方农牧交错带的气候界线及其变迁

THE CLIMATE BOUNDARY AND ITS CHANGE IN FARMING-PASTORAL ECOTONE OF NORTHERN CHINA

关键词:  北方农牧交错带 气候界线 气候变化 气候指标

Key words:  ecotone in Northern China  climate boundary  climate change  climate index

摘要:

北方农牧交错带对于气候变化和人类干扰敏感，在我国经济、社会发展和环境保护方面具有重要 的战略地位。因此，关于其气候界线及变迁的基础研究，可以为农牧交错带的其他深入研究提供科学支 撑。文章基于北方236个气象站点1980～2009年的日气象资料，依据李世奎（20世纪80年代）提出的气 候指标界定北方农牧交错带不同时段的气候界线，通过叠置法分析农牧交错带的核心区域及气候界线变 迁。结果表明:现今（1980～2009年）农牧交错带的分布仍呈现出从东北至西南的带状格局，但范围整体 较早期（20世纪80年代前）有所扩张，分布在内蒙古自治区的交错带面积最广。近30年来，农牧交错带 的气候界线东西摆动，但整体上是向东迁移的。变化趋势与该区域降水量的变化具有一定的相关性，东北 段变化幅度大，由于该区降水量减少而向东变迁;华北区的东部变化幅度较大，而其西部则变化幅度小; 西北段则由于该区降水量增加而向西北延伸。

Abstract:

The farming-pastoral ecotone in Northern China is sensitive to climate change and human interference， where has an important strategic position in China's economic，social development and environmental protection. The basic research on climate boundaries of the ecotone and its change can provide scientific support for similar studies of ecology， agriculture， geography and economy. Based on daily meteorological data of 236 meteorological stations from 1985～2009 in North China， this paper defined the northern ecotone climate boundary according to climate indicators proposed by Li Shikui in 1980s and GIS spatial interpolation analysis. Then the changes of cli- mate boundary were analyzed through overlay analysis.The results showed that:the distribution of ecotone（1980 -2009 years） still showed a strip pattern from northeast to southwest，and its range had been overall expanding. The area of ecotone in Mongolia Autonomous Region was the largest and the climatic boundary moved to eastward in nearly 30 years. The change of the ecotone had correlation with the precipitation. For example， it moved to east due to the rainfall reduction in northeast region， and to the northwest due to the rainfall increase in the northwest region.