Reconstruction of the 1941 GLOF process chain at Lake Palcacocha (Cordillera Blanca, Peru)

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F86652079%3A_____%2F20%3A00523907" target="_blank" >RIV/86652079:_____/20:00523907 - isvavai.cz</a>

Result on the web

<a href="https://www.hydrol-earth-syst-sci.net/24/93/2020/" target="_blank" >https://www.hydrol-earth-syst-sci.net/24/93/2020/</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.5194/hess-24-93-2020" target="_blank" >10.5194/hess-24-93-2020</a>

Result language

angličtina

Original language name

Reconstruction of the 1941 GLOF process chain at Lake Palcacocha (Cordillera Blanca, Peru)

Original language description

The Cordillera Blanca in Peru has been the scene of rapid deglaciation for many decades. One of numerous lakes formed in the front of the retreating glaciers is the moraine-dammed Lake Palcacocha, which drained suddenly due to an unknown cause in 1941. The resulting Glacial Lake Outburst Flood (GLOF) led to dam failure and complete drainage of Lake Jircacocha downstream, and to major destruction and thousands of fatalities in the city of Huaraz at a distance of 23 km. We chose an integrated approach to revisit the 1941 event in terms of topographic reconstruction and numerical back-calculation with the GIS-based open-source mass flow/process chain simulation framework r.avaflow, which builds on an enhanced version of the Pudasaini (2012) two-phase flow model. Thereby we consider four scenarios: (A) and (AX) breach of the moraine dam of Lake Palcacocha due to retrogressive erosion, assuming two different fluid characteristics, (B) failure of the moraine dam caused by the impact of a landslide on the lake, and (C) geomechanical failure and collapse of the moraine dam. The simulations largely yield empirically adequate results with physically plausible parameters, taking the documentation of the 1941 event and previous calculations of future scenarios as reference. Most simulation scenarios indicate travel times between 36 and 70 min to reach Huaraz, accompanied with peak discharges above 10 000 m(3)s(-1). The results of the scenarios indicate that the most likely initiation mechanism would be retrogressive erosion, possibly triggered by a minor impact wave and/or facilitated by a weak stability condition of the moraine dam. However, the involvement of Lake Jircacocha disguises part of the signal of process initiation farther downstream. Predictive simulations of possible future events have to be based on a larger set of back-calculated GLOF process chains, taking into account the expected parameter uncertainties and appropriate strategies to deal with critical threshold effects.

Czech name

—

Czech description

—

Type

J_imp - Article in a specialist periodical, which is included in the Web of Science database

CEP classification

—

OECD FORD branch

10503 - Water resources

Project

<a href="/en/project/LO1415" target="_blank" >LO1415: CzechGlobe 2020 – Development of the Centre of Global Climate Change Impacts Studies</a><br>

Continuities

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Publication year

2020

Confidentiality

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Name of the periodical

Hydrology and Earth System Sciences

ISSN

1027-5606

e-ISSN

—

Volume of the periodical

24

Issue of the periodical within the volume

1

Country of publishing house

DE - GERMANY

Number of pages

22

Pages from-to

93-114

UT code for WoS article

000506835900001

EID of the result in the Scopus database

2-s2.0-85077822472