摘要
黄土高原广泛分布第四纪以来的粉尘堆积,是古气候变化的良好记录。但是,将黄土高原视为一个整体、从地质历史的角度来定量分析粉尘堆积—侵蚀的动态过程及其驱动机制的研究较少。本文利用遥感分析和地统计学中的克里格空间估值法,根据对具有代表性的84个实测黄土—古土壤剖面的分析,计算出黄土高原250ka以来各冰期和间冰期的粉尘堆积量和平均堆积速率,为认识区域粉尘沉降与轨道尺度气候变化的关系提供了新证据:间冰期气候偏暖湿,粉尘堆积较慢;冰期气候偏干冷,粉尘堆积加快。结合黄土高原现代降尘观测数据,进一步估算出黄土高原250ka以来各冰期和间冰期的面状侵蚀速率。初步结果发现,自然背景下黄土高原就存在较强的侵蚀作用;冰期的面状侵蚀速率略强于间冰期。
Loess is widely distributed in Chinese Loess Plateau, and the aeolian sediments have been regarded as one of the most vigorous terrestrial records of paleoclimatic changes during the Quaternary. So far, a large number of investigations have been carried out on palaeoenvironmental changes. However, origination, transportation, and deposition of the eolian sediments, as well as the erosion after deposition, have not been well understood. In this study, we examine 84 individual representative loess-paleosol sections collected from our measurements and literatures, and estimate the total dust deposition amounts and average mass accumulation rates on the Loess Plateau of each glacial or interglacial period over the past 250 ka by remote sensing analysis and Kriging interpolation method. The results provide new evidence for the relation between regional dust deposition and orbit-scale climate changes： the dust accumulation rate is higher in the glacial periods than that in the interglacial periods. Furthermore, based on the modern observation, we estimate average surface erosion rates on the Loess Plateau in each glacial or interglacial period over the past 250 ka as well. The primary results show that there exists relatively intense erosion on the Loess Plateau in the recent geological past, and the surface erosion in the glacial periods is mildly stronger than that in the interglacial periods.
出处
《地理学报》
EI
CSCD
北大核心
2010年第1期37-52,共16页
Acta Geographica Sinica
基金
黄土高原土壤侵蚀与旱地农业国家重点实验室开放基金(10501-228)
高等学校博士学科点专项科研基金项目(20090091110035)
国家自然科学基金(40930103)~~
关键词
黄土高原
第四纪
粉尘堆积
侵蚀
定量估算
Loess Plateau
The Quaternary
dust deposition
erosion
quantitative estimation
