EGU21-13938
https://doi.org/10.5194/egusphere-egu21-13938
EGU General Assembly 2021
© Author(s) 2021. This work is distributed under
the Creative Commons Attribution 4.0 License.

Modelling the impact of a GLOF scenario at Parón lake, Cordillera Blanca, Perú, using a novel multi-phase topographical and geological procedure

Hilbert Villafane Gomez1, Juan C. Torres Lázaro1, Adriana Caballero Bedriñana1, Harrinson W. Jara Infantes1, Enver L. Melgarejo Romero1, Julia E. Araujo Reyes1, Christian Yarleque1, Stephan Harrison2, Ryan Wilson3, Joanne L. Wood2, and Neil F. Glasser4
Hilbert Villafane Gomez et al.
  • 1National Research Institute for Glaciers and Mountain's Ecosystems
  • 2University of Exeter
  • 3University of Huddersfield
  • 4Aberystwyth University

The Cordillera Blanca is undergoing rapid deglaciation due to climatic warming, especially since the late 20th century. This process has resulted in the formation of new glacial lakes and an increase in the volume of existing lakes, some of which pose a risk in the form of Glacier Lake Outburst Floods (GLOF); such as Parón lake in the Cordillera Blanca, which represents a significant hazard to the Caraz city and smaller populations located in the Llullán-Parón sub-basin. Here, we model a potential dam breach and GLOF generation scenario at Parón lake using a novel numerical modelling procedure that, amongst other factors, considers the geological structure of the natural dam. Overall, this procedure includes four distinct phases: (1) estimation of the potential for ice avalanche impact on Parón lake sourced from surrounding glacial cirques; (2) modelling of subsequent impulsive wave generation and propagation; (3) analysis of the hydraulic parameters of a possible breach of the natural dam, considering the non-erodible material within empirical estimations of the hydrograph where the composition of the dam is interpreted based on surface geological mapping and drill sampling carried out in the area; and (4) simulation of a potential GLOF using the FLO-2D model with input data from the previous phases. Modelling results indicate that Parón lake is most at risk from ice avalanches that originate from the adjacent Hatunraju glacier and that such events have the potential to generate impulse waves that could initiate erosion and a subsequent breach of the natural dam. Considering a worst-case ice avalanche scenario, our results indicate the potential generation of a GLOF with average peaks flow of 25,264.22 m3/s. This GLOF event would reach the urban area of the  Caraz city in around 36 - 42 minutes with now rates and flood heights fluctuating between 11.2 m/s to 22.4 m/s and 9.9 m to 19.7 m, respectively.

How to cite: Villafane Gomez, H., Torres Lázaro, J. C., Caballero Bedriñana, A., Jara Infantes, H. W., Melgarejo Romero, E. L., Araujo Reyes, J. E., Yarleque, C., Harrison, S., Wilson, R., Wood, J. L., and Glasser, N. F.: Modelling the impact of a GLOF scenario at Parón lake, Cordillera Blanca, Perú, using a novel multi-phase topographical and geological procedure, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-13938, https://doi.org/10.5194/egusphere-egu21-13938, 2021.

Display materials

Display file

Comments on the display material

to access the discussion