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DEVASTATING LANDSLIDE IN THE PHILIPPINES INDUCED BY HEAVY RAIN . 22 MINERS TRAPPED, BUT ONLY 3 DEATHS 2:30 am, GOOD FRIDAY, APRIL 22, 2011. Walter Hays, Global Alliance for Disaster Reduction, University of North Carolina, USA. DEVASTATING LANDSLIDE IN THE PHILIPPINES: APRIL 22, 2011 .
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DEVASTATING LANDSLIDE IN THE PHILIPPINES INDUCED BY HEAVY RAIN 22 MINERS TRAPPED, BUT ONLY 3 DEATHS 2:30 am, GOOD FRIDAY, APRIL 22, 2011 Walter Hays, Global Alliance for Disaster Reduction, University of North Carolina, USA
LANDSLIDEScause permanent deformation as a result of the downward and outward movements of large volumes of soil and/or rock down slopes under the influence of the force of gravity.
PHYSICS OF LANDSLIDES • Landslides occur naturally. • Landslides can be triggered and/or exacerbated by: 1) Water (from precipitation during a tropical storm, hurricane, or typhoon), or 2) Vibrations (from earthquake ground shaking. • These phenomena either reduce the friction or increase the force down the slope:
LANDSLIDE HAZARDS (AKA POTENTIAL DISASTER AGENTS) • DOWN-SLOPE MOVEMENT OF SOIL AND/OR ROCK (CAN FORM AN “EARTHQUAKE LAKE”) • DOWN-SLOPE FLOW OF WET SOIL (AKA: MUDFLOW; CAN BURY A VILLAGE OR MINERS) • LATERAL SPREADING OF SOIL AND/OR ROCK (CAN DAMAGE INFRA-STRUCTURE)
HAZARDS EXPOSURE VULNERABILITY LOCATION CONTRIBUTORS TO RISK RISK
CAUSES OF DAMAGE SITING AND BUILDING ON UNSTABLE SLOPES SOIL AND ROCK SUCEPTIBLE TO FALLS SOIL AND ROCK SUCEPTIBLE TO TOPPLES SOIL AND ROCK SUCEPTIBLE TO SPREADS LANDSLIDES SOIL AND ROCK SUSCEPTIBLE TO FLOWS CASE HISTORIES PRECIPITATION THAT TRIGGERS SLOPE FAILURE SHAKING GROUND SHAKING THAT TRIGGERS SLOPE FAILURE
E BUILDING ON SLOPES SLOPE FAILURE; DAMAGE LOSS OF FUNCTION ECONOMIC LOSS; DEATH & INJURY UNACCEPTABLE RISK RISK
FORECASTS OF SLOPE FAILURE MONITORING TECHNOLOGIES (E.G., REMOTE SENSING; SENSORS IN LOCAL SLIDES) WARNING SYSTEMS HISTORY OF EACH LANDSLIDE COMPUTER MODEL OF A LANDSLIDE MAPS FOR ZONING DISASTER SCENARIOS HAZARDS AND RISK ASSESSMENT MODELS EMERGING TECHNOLOGIES FOR COPING WITH LANDSLIDES
PURPOSE PREVENTION IDENTIFICATION OF SPECIFIC RISKS IDENTIFICATION OF LANDSLIDE POTENTIAL AFTER STORMS OR EARTHQUAKES TECHNIQUE RETAINING WALLS (LOCAL SCALE) USE OF SITE-SPECIFIC DATA FOR REMEDIATION USE OF REMOTE SENSING FOR WARNING RISK REDUCTION STRATEGIES FOR LANDSLIDES