腾格里地区晚更新世晚期以来沙漠化的时空变化及机制研究

亚洲夏季风影响区西北边缘的环境变化对自然环境变化和人类活动的响应比较敏感。近年来的大量研究基本明确晚更新世晚期以来这一地带普遍发生了大规模沙漠化的基本事实，但对特定地区沙漠化的历史和机制尚不清楚。腾格里就是一个代表性地区。本研究拟选择腾格里沙漠为研究对象，通过不同方向展布的多个地质断面研究腾格里地区中-长时间尺度的沉积记录，重建晚更新世晚期以来沙漠景观的发育历史及时空分布，分析不同时段的风沙源区及其变化，追踪风沙源区气候环境状态及人类活动的历史，解析腾格里地区晚更新世晚期以来沙漠景观变化的过程和成因机制。明确回答：（1）近4万年以来腾格里地区风沙堆积的主要时段有哪些？（2）不同时段沙漠化的驱动因素是什么？该研究不仅有助于我国西北地区沙漠化的驱动机制的正确认识及防沙治沙措施的有效制定，而且能为“丝绸之路经济带”生态文明建设提供参考。

Environmental change at the northwestern margin of the present-day Asian Summer Monsoon (ASM) is sensitive to both climate change and human activity. A basic recognition was obtained along the northwestern margin of the present-day ASM that desertification in large scale during the late stage of the Late Pleistocene, however little is known about history and mechanism of desertification in a specific area. Tengger desert is a case of such kind of area. By selecting the present-day Tengger desert, this project aims to probe the development of desert landscape and its mechanism by reconstructing developing history and temporal and spatial variation of desert landscape, tracing sand sources at specific desertification intervals, and analyzing impulse of climate condition and human activity to sand source area and accumulative area, respectively, via sedimentary documents aligned at geological exploratory lines along different directions. This project ultimately aims to make clear answers to the main time intervals of sand accumulation and formative mechanism of desertification at different time intervals during the late stage of the late-Pleistocene. This research will not only contribute to the proper understanding of desertification mechanism in the northwestern China, and effective formulation of measures to prevent and control desertification, but also contribute to provide a reference for construction of Silk Road Economic Zone ecological civilization.