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中国北方地区保留了晚更新世以来大量的冰缘遗迹.在气候变化背景下,在寒区和干旱区分别出现冰缘地貌、正逆向沙化等问题,综合不同区域的地质遗迹,从时间上的对应关系可进一步分析气候环境变化问题.2008年5-7月调查中,在鄂尔多斯和大同地区分别发现了新的砂楔和土楔;在大兴安岭生态定位研究站设立了8个钻孔和2套自动气象站,开启了冻土、湿地、积雪研究以及现代陆面过程对下伏冻土影响的研究;在黄岗梁地区新发现了一个冻融褶皱;调查了松嫩沙地古沙丘及古土壤活动与冻土进退的关系;发现小兴安岭地区冻土退化显著,岛状冻土散布于海拔相对较高的地区;三江平原西部农业开发强烈改变了地表覆盖,冻土温度升高显著,冻土上限下降明显,甚至厚度较薄的冻土消失.后期工作希望通过综合、集成分析以上结果,探讨我国北方地区晚更新世/全新世的冻土南界及环境变迁.
A large number of ice margin remains have been preserved in the northern part of China since the late Pleistocene.Under the background of climate change, the fringe geomorphology and the positive and negative desertification appear in cold and arid regions, respectively. Based on the geological relics in different regions, Corresponding relationship can be further analyzed climate change problems in the May-July 2008 survey, in the Ordos and Datong areas were found in the new sand wedges and wedges; Daxinganling Ecological Positioning Station set up eight drill holes and two sets Automatic weather station, opened the study of permafrost, wetland, snow cover and modern land surface process on the underlying frozen soil; a new freeze-thaw fold was found in Huanggangliang area; It is found that the permafrost in Xiaoxing’anling area is significantly degraded and the permafrost is scattered in the areas with relatively high altitude. The agricultural development in the western Sanjiang Plain strongly changed the surface coverage and the temperature of the permafrost increased significantly. The upper limit decreased significantly, and even the thinner frozen earth disappeared.The latter part of the work hopes to comprehensively and integrated analysis of the above results, to explore the northern part of the late Pleistocene / Holocene permafrost South boundary and environmental change.