摘要
中国北方季风边缘区沙漠/沙地如何响应气候变化及其反馈研究对于理解干旱半干旱地区现代地表过程及其未来环境演变趋势有重要的科学意义。库布齐沙漠作为中国北方季风边缘区中东部唯一的以流动、半流动为主的沙漠,现代地表景观与周围沙地(如毛乌素沙地、浑善达克沙地、科尔沁沙地等)明显不同。晚第四纪以来库布齐沙漠与季风边缘区中东部沙地环境演化过程到底是否一致,其湿润期究竟发生于何时,尚存颇多争议。区域风成沉积和湖泊沉积记录研究得出的结论明显不同,存在中晚全新世和早中全新世湿度最优期的分歧。对库布齐沙漠风成沉积年代-岩性的概率密度分布(Probability Density Function,PDF)进行处理,与周边沙地风成沉积和湖泊沉积古环境记录进行了对比分析。结果表明:末次盛冰期以来库布齐沙漠与季风边缘区中东部沙地环境演化过程总体一致,27.6—10 ka和晚全新世(2—0 ka),风沙堆积强烈,气候相对干旱;早全新世(10—6 ka)古土壤渐次发育,沙丘逐渐被固定,湿度增加,环境状况有所改善;中全新世(6—2 ka)古土壤广泛发育,沙丘经历固定成壤,气候最为湿润。区域环境演变过程受控于低纬太阳辐射和高纬冰量变化的双重制约。
How the deserts/sandy lands in the monsoonal margin region in northern China responds to climate change and its feedback are of important scientific significance for understanding the modern surface processes in arid and semi-arid regions and their future environmental evolution trends.The Hobq Desert is the only mobile and semi-mobile desert in the middle and east of the monsoonal margin region in northern China.The modern surface landscape is significantly different from the surrounding sandy lands(such as the Mu Us Sandy Land,the Hunshandake Sandy Land,and the Horqin Sandy Land).There are still many disputes about whether the Hobq Desert has the same evolution process as the sandy lands in the middle and east of the monsoonal margin region and when its wet period occurs since the Late Quaternary.The conclusions of regional aeolian deposition and lacustrine deposition records are obviously different,and there is a difference between the optimal period of humidity in the middle and late Holocene and the early and middle Holocene.Through the process of the probability density distribution(Probability Density Function,PDF)of the aeolian sedimentary age-lithology of the Hobq Desert and its comparison with paleoenvironment records of aeolian deposition and lacustrine deposition from the surrounding sandy lands,it is found that:the environment evolution process of the Hobq Desert is generally consistent with that of sandy lands in the middle and east of the monsoonal margin region since the Last Glacial Maximum.During 27.6-10 ka and the Late Holocene(2-0 ka),sand activity was strong and the climate was relatively arid;in the early Holocene(10-6 ka),paleosols began to develop,sand dunes were gradually fixed,humidity increased,and environmental conditions were improved;in the Middle Holocene(6-2 ka),paleosols developed extensively,sand dunes were fixed,and climate was obviously humid.The process of regional environmental evolution is controlled by both solar insolation in low-latitude and variations of ice volume in hi
作者
张小梅
靳鹤
龄刘冰
Zhang Xiaomei;Jin Heling;Liu Bing(Key Laboratory of Desert and Desertification,Northwest Institute of Eco-Environment and Resources,Chinese Academy of Sciences,Lanzhou 730000,China;University of Chinese Academy of Sciences,Beijing 100049,China)
出处
《中国沙漠》
CSCD
北大核心
2021年第5期81-93,共13页
Journal of Desert Research
基金
国家自然科学基金项目(41977393)。
关键词
末次盛冰期
库布齐沙漠
气候变化
沙漠演化
成因机制
Last Glacial Maximum
Hobq Desert
climate change
desert evolution
driving mechanisms
