雅鲁藏布江中游约居段堵江事件研究  

The Damming Event in the Yueju Section of the Middle Yarlung Tsangpo River

作　　者：朵耀华 胡海平 叶长盛[1] 刘金花 DUO Yaohua;HU Haiping;YE Changsheng;LIU Jinhua(School of Earth Sciences,East China University of Technology,330013,Nanchang,PRC)

机构地区：[1]东华理工大学地球科学学院,南昌330013

出　　处：《江西科学》2024年第3期520-525,625,共7页Jiangxi Science

基　　金：国家自然科学基金项目(41901002);东华理工大学博士科研启动基金项目(DKBH2017104)。

摘　　要：雅鲁藏布江中游两岸冰川发育,峡谷与宽谷呈串珠状分布,峡谷区山高谷深,易发生堵江事件。其中,发育于日喀则宽谷和大竹卡-约居峡谷的大竹卡古堰塞湖成因尚不明确。为探究其成因,以大竹卡-约居峡谷出口的约居段为研究区,通过地貌调查和粒度分析方法,发现大竹卡古堰塞湖可能在此处形成堰塞坝。地貌和粒度分析表明,上部沟谷沉积物多为冰碛物,沟谷下部为泥石流沉积物,推断在约居南岸山谷可能发生过冰缘湖泊溃决。其溃决洪水携带冰碛物,并冲刷山谷风化碎屑物质,形成泥石流;泥石流在陡峭山谷中,倾泻而下堵塞雅鲁藏布江,形成的坝体可能对应于大竹卡古堰塞湖。随着全球气候变暖,高原山区冰川退缩,冰缘湖泊溃决的概率增加。本研究对于青藏高原的防洪减灾具有指导意义。The middle reaches of the Yarlung Tsangpo River are characterized by broad valleys intercalated with gorges.The deep gorges are easily dammed.However,the damming event of the Dazhuka dammed palaeo-lake was unclear.To explore its causes,We studied the deep valley area of the middle Yarlung Tsangpo River,specifically at the south bank of the outlet of the Dazhuka-Yueju gorge.Herein,the geomorphological features and particle sizes of the sediments were analyzed.The results suggest that the upper part of the valley is covered by moraine,and the lower part is covered by debris flows.The sedimentary features indicate an outburst of a periglacial lake event in the valley.The burst flood carries moraine,and washes the valley weathered debris material,forming debris flow.The high energy debris flow poured down to the Yarlung Tsangpo River and formed a dam,which is likely the dam of the Dahzuka palaeo-lake.With the global warming of the modern climate,the periglacial lake is easily failed and leads to outburst floods on the Tibetan Plateau.This research has guiding significance for disaster prevention and reduction in this region.

关 键 词：古堰塞湖 大竹卡-约居峡谷 粒度分析 堵江事件 

分 类 号：P931.7[天文地球—自然地理学]