摘要
中国北方农牧交错带和非洲萨哈尔带均为处在季风尾闾带的干旱向半湿润气候过渡的地带。通过对比分析 ,发现两个地带自然地理环境及其全新世以来的环境演变等具有很大程度的相似性 ;自全新世以来 ,两个地带均出现过几乎同步的 8个千年尺度的冷暖、干湿旋回 ;在近百年的干湿变化方面都有 10～ 2 0a变化周期 ;在少雨期和多雨期的转变过程中非洲萨哈尔带较中国北方农牧交错带提前 5a以上。这一超前信息的存在 ,为中国北方农牧交错带的气候预测提供了一个重要的前兆因素。
The modern environment of North China agro-pastoral zone and Africa Sahelian belt, controlled by monsoon climate, is very similar in the aspect of the transition between arid deserts to sub-humid savanna or forest grassland. The Holocene environmental change in both regions are characterized by abrupt termination and starting of mid-Holocene humid period, which also punctuated by episodic dry phases. The existing 8 millennial scale of climatic fluctuation rhythm and especially 8 arid/dry phases in full Holocene are synchronous except the beginning of the Medieval Warm Period (1 500—1 000 a BP)in which it was wetter in north China agro-pastoral zone but extremely arid in Africa Sahelian belt. The wet / dry oscillations on centennial and decadal scale are more obvious in both regions almost synchronously since 1000 a BP. The variation of precipitation showed approximately synchronous 10～20 a relative high/low periodic oscillations and pronounced drying trend in both region since 1900AD. The era of entering dry or wet period was some what more than 5 years earlier in Sahelian region than in North China agro-pastoral zone.
出处
《地学前缘》
EI
CAS
CSCD
2002年第1期121-128,共8页
Earth Science Frontiers
基金
国家重点基础研究规划项目 (G2 0 0 0 0 186 0 4
G2 0 0 0 0 4870 1)
国家自然科学基金资助项目 ( 4 0 0 0 710 12 )
