CS: The Galtur Avalanche in Austria, 1999

Question 1

Nature + causes

Answer 1

• heavy snowfall, from a series of snowstorms over 2 weeks, deposited 4m of snow, in which rapid T°C fluctuations caused unstable snowpack layers to form
• this triggered a powdered, slab avalanche on a steep 40° slope, that travelled >2km, at up to 290km/hr, in which snow mass was 50m high in places

Question 2

Impacts on lives + property

Answer 2

• avalanche killed 31 ppl (inc tourists + residents) + destroyed or severely damaged 25 buildings, inc hotels + homes, in which total damage was est at €20M
• 100s had to be evacuated, + >2000 ppl were stranded in valley

Question 3

Prediction + monitoring of avalanches

Answer 3

• Austrian Avalanche Warning Service monitored weather + snow conditions, using snowpack testing, remote sensors + helicopter surveys to issue a lvl 4 (high) warning, however, bc Galtur hadn’t experienced a major avalanche in >100 yrs, it underestimated risks

Question 4

Hazard mapping

Answer 4

• pre-1999 hazard maps existed, however, avalanche’s path hadn’t been accurately modelled + followed a rare route down a side valley, highlighting mapping was incomplete + need for modern avalanche models

Question 5

Preparedness

Answer 5

• minimal structural defences were present in Galtur, w no avalanche barriers, snow fences or deflection dams installed above the village
• Galtur was only in a ‘blue zone’, meaning hotels, chalets + homes were still allowed to be built w caution + building codes didn’t require avalanche resistant reinforcement, + so many were built in vulnerable areas

Question 6

Conclusion/evaluation

Answer 6

• overall, the Galtur avalanche shows how relying on outdated hazard maps + low risk perception can lead to severe impacts, even in HICs

Question 7

Overall conclusion for hazards resulting from mass movements

Answer 7

• overall, mass movements like landslides in HK + avalanches in Galtur, highlight the need for effective disaster preparedness to dec the impacts of natural hazards + prevent them from becoming disasters
• this is illustrated by HK’s strong hazard management, which has dec landslide risks, while Galtur’s outdated planning led to a deadly avalanche, demonstrating that failure to update hazard strategies can have tragic consequences