LANDSLIDE DISASTER IN COLOMBIA May 18, 2015 A PRIMER OF KNOWLEDGE THAT CAN MULTIPLY AND SPILL Walter Hays, Global Alliance for Disaster Reduction, Vienna, Virginia, USA Walter Hays, Global Alliance for Disaster Reduction, Vienna, Virginia, USA

LANDSLIDE IN COLOMBIA The landslide occurred in the municipality of Salgar, Colombia, about 60 miles (100 kilometers) southwest of Medellin, President Juan Manuel Santos said. Rescuers are searching for survivors, he said, but it isn't clear yet how many people are missing.

LANDSLIDE IN COLOMBIA

“Heavy rains in northwest Colombia caused the landslide at 03:00 am local time just before dawn on Monday morning while people were sleeping, killing at least 62 people, injuring at least 37, and leaving many physical and emotional healthcare problems”

A river of mud and water overran roads and bridges and crashed into homes, practically wiping the small town of Santa Margarita off the map.

Note: Photographs are used solely for educational purposes without any financial benefit.

“A RIVER OF MUD” (credit: Reuters)

DAMAGED HOUSES (credit: Reuters)

SEARCHING FOR RELATIVES (credit: Reuters)

TRYING TO CLEAN UP: A HUGE TASK (credit: Reuters)

SURVIVORS HOPING TO START OVER (credit: Reuters)

SURVIVORS LEAVING (credit: Reuters)

PRESIDENT JUAN MANUEL SANTOS (credit: Reuters)

LEADERSHIP President Juan Manuel Santos flew over the affected area and met with local officials. "No one can bring the deceased back to you, that is something we deeply regret, but we have to get through this disaster and look to the future with bravery and strength," he said.

LANDSLIDE HAZARDS

LANDSLIDES represent permanent deformation caused by the downward and outward movements of large volumes of soil and/or rock down slope 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 ground shaking during an earthquake. These phenomena either reduce the friction or increase the force on 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) LATERAL SPREADING OF SOIL AND/OR ROCK (CAN DAMAGE INFRA- STRUCTURE)

COMMUNITYCOMMUNITY DATA BASES AND INFORMATION HAZARDS: GROUND SHAKING GROUND FAILURE SURFACE FAULTING TECTONIC DEFORMATION TSUNAMI RUN UP AFTERSHOCKS HAZARD MAPS INVENTORY VULNERABILITY LOCATION RISK ASSESSMENT RISK ACCEPTABLE RISK UNACCEPTABLE RISK LANDSLIDE DISASTER RISK REDUCTION PREVENTION/MITIGATION PREPAREDNESS EMERGENCY RESPONSE RECOVERY and RECONSTRUCTION POLICY OPTIONS

RISK ASSESSMENT FOR LANDSLIDES

PLANET EARTH HAS THOUSANDS OF LARGE- VOLUME “LANDSLIDE LABORATORIES” EACH LANDSLIDE PROVIDES VALUABLE LESSONS ON DISASTER RISK REDUCTION

HAZARDSHAZARDS ELEMENTS OF RISK EXPOSUREEXPOSURE VULNERABILITYVULNERABILITY LOCATIONLOCATION RISKRISK

SITING AND BUILDING ON UNSTABLE SLOPES LANDSLIDES SOIL AND ROCK SUCEPTIBLE TO FALLS SOIL AND ROCK SUCEPTIBLE TO TOPPLES SOIL AND ROCK SUCEPTIBLE TO SPREADS SOIL AND ROCK SUSCEPTIBLE TO FLOWS PRECIPITATION THAT TRIGGERS SLOPE FAILURE SHAKING GROUND SHAKING THAT TRIGGERS SLOPE FAILURE CAUSES OF DAMAGE CASE HISTORIES

WORST LANDSLIDE: 1970 IN PERU A M7.7 earthquake that occurred offshore Peru in 1970 triggered a massive landslide of snow and rock in the Nevados Huascaran Mountains. 100 million cubic km of rock and soil buried Yungay, Ramrahirca, and several villages, killing 18,000.

USE KNOWLEDGE TO ANTICIPATE LANDSLIDES– BEFORE MAY 12, 2008

EARTHQAKE TRIGGERED LANDSLIDES: BEICHUAN, CHINA, MAY 12, 2008

USE KNOWLEDGE TO ANTICIPATE LANDSLIDES: AFTER HURRICANES HURRICANE STAN: OCTOBER 2005 DEVASTATING MUDSLIDES WERE TRIGGERED BY PROLONGED, HEAVY PRECIPITATION.

E BUILDING ON SLOPES UNACCEPTABLE RISK SLOPE FAILURE; DAMAGE LOSS OF FUNCTION ECONOMIC LOSS; DEATH & INJURY RISKRISK

ASSESSMENT OF DISASTER RISK FOR LANDSLIDES

EMERGING TECHNOLOGIES FOR LANDSLIDES FORECASTS OF SLOPE FAILURE MONITORING TECHNOLOGIES (E.G., REMOTE SENSING; SENSORS IN LOCAL SLIDES) WARNING SYSTEMS FORECASTS OF SLOPE FAILURE MONITORING TECHNOLOGIES (E.G., REMOTE SENSING; SENSORS IN LOCAL SLIDES) WARNING SYSTEMS DATABASES FOR EACH LANDSLIDE COMPUTER MODEL OF A LANDSLIDE MAPS DISASTER SCENARIOS HAZARDS AND RISK ASSESSMENT MODELS DATABASES FOR EACH LANDSLIDE COMPUTER MODEL OF A LANDSLIDE MAPS DISASTER SCENARIOS HAZARDS AND RISK ASSESSMENT MODELS

RISK REDUCTION STRATEGIES FOR LANDSLIDES

PURPOSE PREVENTION IDENTIFICATION OF SPECIFIC RISKS IDENTIFICATION OF LANDSLIDES AFTER STORMS OR EARTHQUAKES PURPOSE PREVENTION IDENTIFICATION OF SPECIFIC RISKS IDENTIFICATION OF LANDSLIDES AFTER STORMS OR EARTHQUAKES TECHNIQUE RETAINING WALLS (LOCAL SCALE) USE OF SITE- SPECIFIC DATA USE OF REMOTE SENSING FOR WARNING TECHNIQUE RETAINING WALLS (LOCAL SCALE) USE OF SITE- SPECIFIC DATA USE OF REMOTE SENSING FOR WARNING

SITE-SPECIFIC DATA:IDENTIFICATION OF SPECIFIC RISKS INTEGRATION OF SITE-SPECIFIC GEOLOGIC AND ENGINEERING DATA DURING CON- STRUCTION OF A HIGHWAY CAN PREVENT LOSS OF FUNCTION FROM LANDSLIDES.

SITE-SPECIFIC DATA: IDENTIFICATION OF SPECIIC RISKS LOSS OF FUNCTION IS REDUCED WHEN SITE-SPECIFIC GEOLOGIC AND ENGINEERING DATA ARE WELL INTEGRATED.

IDENTIFICATION AND WARNING: REMOTE SENSING AFTER HEAVY RAINS, JULY 2007

IDENTIFICATION OF EARTHQUAKE LAKE: REMOTE SENSING, CHINA; MAY 31, 2008

RISK REDUCTION STRATEGIES FOR LANDSLIDES PURPOSE STABALIZE HAZARDOUS SITUATIONS AVOID SPECIFIC LANDSLIDE HAZARDS PURPOSE STABALIZE HAZARDOUS SITUATIONS AVOID SPECIFIC LANDSLIDE HAZARDS TECHNIQUE SITE MODIFI- CATION MAPS OF SPECIFIC HAZARDS: LAND USE ZONING ORDINANCES TECHNIQUE SITE MODIFI- CATION MAPS OF SPECIFIC HAZARDS: LAND USE ZONING ORDINANCES

SITE MODIFICATION: STABALIZE HAZARDOUS SITUATIONS, MAY 2008

SITE MODIFICATION: STABALIZE HAZARDOUS SITUATIONS

A NEW CHANNEL: MODIFICATION OF SITE

RISK REDUCTION STRATEGIES FOR LANDSLIDES PURPOSE SEARCH AND RESCUE EVACUATION PURPOSE SEARCH AND RESCUE EVACUATION TECHNIQUE COMMUNITY EMERGENCY RESPONSE PLAN COMMUNITY EVACUATION PLAN TECHNIQUE COMMUNITY EMERGENCY RESPONSE PLAN COMMUNITY EVACUATION PLAN

SEARCH AND RESCUE: COMMUNITY EMERGENCY RESPONSE PLAN

DEBRIS REMOVAL: COMMUNITY EMERGENCY RESPONSE PLAN

AN URGENT NEED FOR EVACUATION AS LANDSLIDES DAM RIVE R Evacuation needed! The rising lake of water behind the debris dam threatened to break through its banks and send a wall of water into the entire epicentral area.

TANGJIASHAN, LARGEST OF 69 "QUAKE LAKES"

ONE OF 69 "QUAKE LAKES": BEI HE RIVER DAMMED BY LANDSLIDE DEBRIS

THOUSANDS EVACUATE Warned by government officials, survivors in Beichuan (100 km; 60 miles south) and other towns down river evacuated as fast as possible, using every available means.

EVACUATION: COMMUNITY EVACUATION PLAN

TEMPORARY SHELTERS: COMMUNITY EVACUATION PLAN

SEARCH AND RESCUE: COMMUNITY EMERGENCY RESPONSE PLAN WHEN A MUDSLIDE BURIES A TOWN, SEARCH AND RESCUE BECOMES VERY URGENT AND VERY COMPLICATED.

TEN WORST NATURAL DISASTERS DURING EL SALVADOR EARTHQUAKE AND LANDSLIDES $3,500 MILLION ECONOMIC LOSS WITH $300 MILLION INDEMNIFIED BY INSURANCE 800 DEATHS $3,500 MILLION ECONOMIC LOSS WITH $300 MILLION INDEMNIFIED BY INSURANCE 800 DEATHS

NATURAL DISASTERS: 2003 SEVERE STORMS AND LANDSLIDES AUSTRIA, FRANCE, ITALY, AND SWITZERLAND AUGUST DAMAGE TO BUILDINGS AND INFRASTRUCTURE $500 M LOSS $100 M INSURED LOSS 5 DEATHS DAMAGE TO BUILDINGS AND INFRASTRUCTURE $500 M LOSS $100 M INSURED LOSS 5 DEATHS

NATURAL DISASTERS: 2003 FLOODS AND LANDSLIDES CHINA MAY-JULY 2,000,000 BUILDINGS/HOMES FLOODED POWER OUTAGES AGRICULTURAL LOSSES $8,000 M LOSS $--0 INSURED LOSS 800 DEATHS 2,000,000 BUILDINGS/HOMES FLOODED POWER OUTAGES AGRICULTURAL LOSSES $8,000 M LOSS $--0 INSURED LOSS 800 DEATHS

THE GOAL IS LANDSLIDE- DISASTER-RESILIENT URBAN DEVELOPMENT IN EVERY COMMUNITY.