毛乌素沙地历史时期沙漠化——基于北大池湖泊周边沉积剖面粒度的研究

Historical Desertification in the Mu Us Sandy Land: An analysis on grain size data from the Beidachi section

通过深入分析毛乌素沙地内北大池古城东侧一处包含人类活动层的沉积剖面的粒度参数,结合14 C、OSL(光释光)测年和历史文献记载,本研究重建了北大池周边历史时期以来的环境及人类活动过程。结果显示:北大池湖泊在历史时期处于断续退缩过程之中,剖面北侧的河流水量一直减少。剖面中粗颗粒含量的变化与湖泊退缩和河流水量减少存在较好的相关性,剖面点周边地表沙丘出现的大致时间为明末,该结论与众多测年结果相符。该研究对理解毛乌素沙地环境变化的空间尺度具有较好的启示意义,同时在揭示沙漠化的内部环境变化过程中具有重要作用。

Historical desertification in the Mu Us Sandy Land is a focus on the study of the relationship between nature factors and human beings. In this paper, a section located at southwest of the Mu Us Sandy Land was studied based on an analysis of grain size parameters. Together with an analysis on its chronology and historical record, the results showed that the Beidachi Lake and the river close to the section had retreated continuously in history and the dunes appeared at the end of Ming dynasty approximately. This study would give new knowledge for understanding the special-temporal change of the Mu Us Sandy Land in histo- ry and had great significance in studying Mu Us Sandy Land environmental change.