文章基本信息

标题：Prevention of outburst floods from periglacial lakes at Grubengletscher, Valais, Swiss Alps
本地全文：下载
作者：Wilfried Haeberli ; Andreas Kääb ; Daniel Vonder Mühll 等
期刊名称：Journal of Glaciology
印刷版ISSN：0022-1430
电子版ISSN：1727-5652
出版年度：2001
卷号：47
期号：156
页码：111-122
DOI：10.3189/172756501781832575
出版社：Cambridge University Press
摘要：Flood and debris-flow hazards at Grubengletscher near Saas Balen in the Saas Valley, Valais, Swiss Alps, result from the formation and growth of several lakes at the glacier margin and within the surrounding permafrost. In order to prevent damage related to such hazards, systematic investigations were carried out and practical measures taken. The evolution of the polythermal glacier, the creeping permafrost within the large adjacent rock glacier and the development of the various periglacial lakes were monitored and documented for the last 25 years by photogrammetric analysis of annually flown high-resolution aerial photographs. Seismic refraction, d.c. resistivity and gravimetry soundings were performed together with hydrological tracer experiments to determine the structure and stability of a moraine dam at a proglacial lake. The results indicate a maximum moraine thickness of > 100 m; extremely high porosity and even ground caverns near the surface may have resulted from degradation of sub- and periglacial permafrost following 19th/20th-century retreat of the partially cold glacier tongue. The safety and retention capacity of the proglacial lake were enhanced by deepening and reinforcing the outlet structure on top of the moraine complex. The water level of an ice-dammed lake was lowered and a thermokarst lake artficially drained.