Natural Hazards

, Volume 54, Issue 2, pp 469–481

Repeated glacial-lake outburst floods in Patagonia: an increasing hazard?

  • Alejandro Dussaillant
  • Gerardo Benito
  • Wouter Buytaert
  • Paul Carling
  • Claudio Meier
  • Fabián Espinoza
Original Paper

DOI: 10.1007/s11069-009-9479-8

Cite this article as:
Dussaillant, A., Benito, G., Buytaert, W. et al. Nat Hazards (2010) 54: 469. doi:10.1007/s11069-009-9479-8

Abstract

Five similar glacial-lake outburst floods (GLOFs) occurred in April, October, December 2008, March and September 2009 in the Northern Patagonia Icefield. On each occasion, Cachet 2 Lake, dammed by the Colonia Glacier, released circa 200-million m3 water into the Colonia River. Refilling has occurred rapidly, such that further outbreak floods can be expected. Pipeflow calculations of the subglacial tunnel drainage and 1D hydraulic models of the river flood give consistent results, with an estimated peak discharge surpassing 3,000 m3 s−1. These floods were larger in magnitude than any flood on record, according to gauged data since 1963. However, geomorphological analysis of the Colonia valley shows physical evidence of former catastrophic outburst floods from a larger glacial-lake, with flood discharges possibly as high as 16,000 m3 s−1. Due to potential impacts of climate change on glacier dynamics in the area, jökulhlaups may increase future flood risks for infrastructure and population. This is particularly relevant in view of the current development of hydropower projects in Chilean Patagonia.

Keywords

Jökulhlaup Outburst flood Patagonia Glacial-lake Climate change 

List of symbols

a,b

Empirical coefficients for Clague-Mathews and Walder and Costa equations

h

Head loss

λ

Friction factor

K

Head loss coefficient

D

Diameter of conduit

R

Hydraulic radius = D/4Φ

U

\( {\text{Bulk}}\,{\text{flow}}\,{\text{velocity}} = {Q \mathord{\left/ {\vphantom {Q {{{\pi D^{2} } \mathord{\left/ {\vphantom {{\pi D^{2} } {4\phi }}} \right. \kern-\nulldelimiterspace} {4\phi }}}}} \right. \kern-\nulldelimiterspace} {{{\pi D^{2} } \mathord{\left/ {\vphantom {{\pi D^{2} } {4\phi }}} \right. \kern-\nulldelimiterspace} {4\phi }}}} \)

Q

Discharge

G

Acceleration due to gravity

ks

Equivalent sand grain roughness for ice walls

ν

Kinematic viscosity

Re

\( {\text{Reynolds}}\,{\text{number}} = {{UD} \mathord{\left/ {\vphantom {{UD} \nu }} \right. \kern-\nulldelimiterspace} \nu } \)

Φ

Pipe shape factor

Copyright information

© Springer Science+Business Media B.V. 2009

Authors and Affiliations

  • Alejandro Dussaillant
    • 1
    • 2
    • 3
    • 8
  • Gerardo Benito
    • 4
  • Wouter Buytaert
    • 5
    • 6
  • Paul Carling
    • 3
  • Claudio Meier
    • 1
    • 8
  • Fabián Espinoza
    • 7
  1. 1.Ingeniería Civil, Barrio UniversitarioUniversidad De ConcepciónConcepciónChile
  2. 2.Centro Ambiental EULAUniversidad de ConcepciónConcepciónChile
  3. 3.School of GeographyUniversity of SouthamptonSouthamptonUK
  4. 4.Centro de Ciencias MedioambientalesCSICMadridSpain
  5. 5.School of Geographical SciencesUniversity of BristolBristolUK
  6. 6.Imperial CollegeLondonUK
  7. 7.Dirección General de AguasRegión de AysénCoyhaiqueChile
  8. 8.Centro de Investigaciones en Ecosistemas de la PatagoniaCoyhaiqueChile

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