10_09 IAEG petley v2

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Non-seismic landslide hazards along the Himalayan Arc : 

Non-seismic landslide hazards along the Himalayan Arc D. Petley, N. Rosser Durham University D. Karim, S. Wali, N. Ali, N. Nasab & K. Shaban Focus Humanitarian Assistance, Pakistan Powerpoint file available at: http:daveslandslideblog.blogspot.com

CRED data for landslide fatalities : 

CRED data for landslide fatalities 6587 Other disasters 2002-2009 (CRED database) Earthquake: 429,877 River flood: 37,860 Storm: 166,410 Volcano: 221

Slide 3: 

Landslides from the Kashmir earthquake Landslides from the Wenchuan earthquake Other disasters 2002-2009 (CRED database) Earthquake: 429,877 River flood: 37,860 Storm: 166,410 Volcano: 221 The (more) true human cost of landslides 82,439

Global fatal rainfall-induced landslides – 2006 to 2009 : 

Global fatal rainfall-induced landslides – 2006 to 2009

Global landslide mortality model(non-seismic) : 

Global landslide mortality model(non-seismic)

Slide 6: 

Himalayan Arc

Himalayan Arc – 2004 to 2009 : 

Himalayan Arc – 2004 to 2009

Annual cycle in pentads (five day bins) : 

Annual cycle in pentads (five day bins)

Trend in occurrence? : 

Trend in occurrence?

Slide 10: 

Attabad

Slide 13: 

Slope identified as unstable in 2003

Slide 16: 

1. Progressive failure over >7 years 2. Catastrophic failure event in Jan 2010 with no trigger 3. Emplacement of rockslide onto lake sediments triggered secondary high velocity mudflow event

1858 landslide dam : 

1858 landslide dam

Wenchuan Risk TableYang et al 2010 : 

Wenchuan Risk TableYang et al 2010

Data driven flood estimation : 

Data driven flood estimation Typical values of maximum discharge using this approach: 14,000 cumecs (Costa and Schuster 1986) 12,000 - 26,000 cumecs (Walder and O’Connor 1997)

Management of the hazard : 

Management of the hazard Initial management response was the construction of a spillway. Original intention: 30 metres deep Actual depth at time of overtopping: 15 metres Final spillway was very narrow and unlined

Evacuations : 

Evacuations After the landslide, Focus installed sirens in 15 villages People in most hazardous areas relocated into camps Boat service established on lake, but enormous hardship upstream One month before overtopping NDMA evacuated 15,000 people downstream of barrier

Seepage : 

Seepage

Seepage development : 

Seepage development

Slide 26: 

Prediction of date of overtopping

Water level rise : 

Water level rise

Overtopping behaviour : 

Overtopping behaviour

Evolution of spillway discharge : 

Evolution of spillway discharge

Spillway discharge – depth relationship : 

Spillway discharge – depth relationship

Spillway evolution : 

Spillway evolution

Management problems : 

Management problems Karakoram Highway remains blocked After recent floods, Gilgit-Baltistan was cut off to north and south Loss of productive land Loss of cash crop markets Landslide hazard remains Progressive failure GLOF Seismic event Landslide into lake Should the lake level be lowered?

Jay Village, Afghanistan : 

Jay Village, Afghanistan 30th April 2010: Jay means “blockage” Powerpoint file available at: http:daveslandslideblog.blogspot.com

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