青藏高原东部边缘地区第四纪泥石流发育特性研究

Studies on Debris Flow Development Properties in Quaternary on the Eastern Edge of Qinghai-Tibet Plateau

在实地考查和试验分析的基础上,对青藏高原东部边缘地区第四纪代表性泥石流堆积剖面进行了分析;根据阶地特征、泥石流堆积剖面与地质年代的关系,白龙江流域与小江流域第四纪泥石流活动均可分为8期,白龙江流域第四纪泥石流活动主要在1.5 Ma,0.73 Ma,0.565～0.425 Ma,0.245～0.165 Ma,(116.8±9.9)ka,50～25 ka,5～4 ka,3 ka至今,小江流域第四纪泥石流活动主要在1.42 Ma,0.985 Ma,0.562～0.52 Ma,0.218 Ma,0.137 Ma,14ka,0.73 ka,3 ka至今。根据对青藏高原东部边缘地区泥石流堆积层及活动周期的分析,结合泥石流与冰期间冰期气候特征的比较,得出青藏高原东部边缘地区泥石流活动过程既具有一致性特点,也具有非平衡性的特性。

Based on the investigation in the field and test analysis,typical sediment profile of debris flow on the eastern edge of Qinghai-Tibet plateau was analyzed.According to the relationship among terrace geomorphology,debris flow deposition profile and the geological age,the Quaternary debris flow activities in Bailongjiang River basin and Xiaojiang River basin could be divided into eight periods.The Quaternary debris flow activities in Bailongjiang River basin were mainly concerning 1.5 Ma,0.73 Ma,0.565~0.425 Ma,0.245~0.165 Ma,（116.8±9.9）ka,50~25 ka,5~4 ka,3 ka,and the Quaternary debris flow activities in Xiaojing River basin were concerning 1.42 Ma,0.985 Ma,0.562~0.52 Ma,0.218 Ma,0.137 Ma,14 ka,0.73 ka,0.3 ka.Based on analysis of debris flow deposits and activity cycle on eastern edge of Qinghai-Tibet plateau as well as comparison between debris flow and climate characteristics in glacial and interglacial areas,the following conclusions were drawn： the debris flow activity process on the eastern edge of Qinghai-Tibet plateau was consistent and it had unbalanced features.