中国东部南北方过渡带淮河半湿润区全新世气候变化  

THE HOLOCENE CLIMATIC CHANGES OF THE HUAIHE RIVER SEMI-HUMID REGION IN THE NORTH AND SOUTH TRANSITION ZONE OF THE EASTERN CHINA

作　　者：秦小光[1] 张磊[1] 穆燕[1] 

机构地区：[1]中国科学院地质与地球物理研究所,中国科学院新生代地质与环境重点实验室,北京100029

出　　处：《第四纪研究》2015年第6期1509-1524,共16页Quaternary Sciences

基　　金：中国工程院重大咨询项目“淮河流域环境与发展问题研究”（批准号：2012-ZD-11-1-1）、国家自然科学基金项目（批准号：41372187、41172158、40472094和40024202）、国家重点基础研究发展规划项目（973项目）（批准号：2010CB950200）和中国科学院知识创新工程项目（批准号：KZCX2-YW-Q1-03）共同资助

摘　　要：淮河流域位于中国东部的南北方过渡带,属于半湿润区气候环境,这里既有冬季风从北方干旱半干旱区携带而来的粉尘堆积,又有江淮地区特有梅雨天气,但与北方干旱半干旱区和南方湿润区均存在着差异,因此其古气候环境变化对于理解东亚古气候格局具有十分重要的意义,然而由于缺乏合适的材料,对淮河流域古气候的研究一直是全球变化研究中空白地区.本文针对襄城的一个全新世黄土-古土壤连续剖面,根据粉尘沉降动力学原理,利用粉尘搬运距离、风力强度、春季近地面气温和有效湿度等几个半定量和定性指数,分析了淮河流域的全新世气候波动特征,结果表明：1）淮河半湿润区与北方干旱半干旱区的湿度变化总体有反向波动趋势.大约7.0～3.8kaB.P.是北方粉尘源区的全新世适宜期,而在淮河流域环境只有小幅改善.淮河流域的适宜期在大约3.8～ 1.8ka B.P.期间,晚于北方干旱区.2）淮河流域全新世时期冬季风强度一直在持续减弱,而有效湿度一直在持续增加.大约1.8ka B.P.以来形成的黄土层是因粉尘源区扩展所致,并非因冬季风加强.3）淮河流域这种异于北方干旱半干旱区的全新世气候特征是由于印度季风减弱、西太平洋副高西伸增强造成江淮地区梅雨加强,同时也是淮河地区冬季风减弱致使梅雨带北移的共同作用所造成的.The Huaihe watershed is the semi-humid climate region located in the North and South transition zone of the Eastern China. In the region, both winter and summer monsoons play an important role in climate and environment. There are loess depositions which dusts were transported by the winter monsoon from the northwestern arid and semi-arid areas and the rich precipitation of Jianghuai-specific plum rains, directly related to the summer monsoon. However, the climate of the region is different from both the North and the South of China. Therefore, the revealing paleo-climate change of the region is particularly important for understanding of the paleo-climatic pattern of the Eastern Asia. In history, the Yellow River had diverted into the Huaihe basin and flowed into the East China Sea. Because the Yellow River-carried sand and clay formed thick depositions in most regions of the Huaihe basin, it is an important issue to find a continuous Holocene wind-blown loess section in the region. In the study, a Holocene loess-paleosol section （33.95021°N, 113.47992° E; 96m a.s.1.） in Xiangcheng County, Henan Province of the northwest of the Huaihe basin was chosen to analyze the Holocene climate. The loess section located on a loess platform in the piedmont of Funiu Mountain, about 10km far from the Wohe River ever diverted by the Yellow River. The wind-blown dusts of the region come from the same source areas as that of the Loess Plateau. The top about 2.5m of the loess formation was sampled at a 2cm interval. Its 0- 17cm is the light-brown farmed soil layer. The 17-35cm part is a loess thin layer and the 35- ll0cm consists of a dark grey paleosol layer with rich organic matter. The part below ll0cm is loess in which a lot of small calcium nodules developed. The age of the section is determined by organic carbon 14C dating and suggested for 12.5ka B.P. in bottom of the section. The section was analyzed on the basis of dust settlement dynamics. The Holocene climate fluctuations are discussed according to several indi

关 键 词：淮河流域 黄土古土壤 全新世气候 粉尘沉降动力学 

分 类 号：P532[天文地球—古生物学与地层学] P534.632[天文地球—地质学]