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Landslide Hazard

Maps

of Korea

By Kyoung-Doo Oh, Ph.D.

Professor, Korea Military Academy육군사관학교Korea Military Acad-emy

자연재해저감기술개발사업단

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How to develop precision landslide hazard maps? How to develop precision landslide hazard maps?

Contents

22

Let us explore landslide hazrd maps!!Let us explore landslide hazrd maps!!33

What are the problems with landslides?What are the problems with landslides?11

How to use landslide hazard maps?How to use landslide hazard maps?44

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What are the problems with landslides?

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Rapid increase of loss related with landslides for recent 10

years

Average annual loss : 779ha, casualties : 11 deaths,

property damage : 120 million dallars

Unprecedented extreme rainfalls due to global climate change : 58 casualties

during heavy rainstorms in 2011

Difficult to isolate ‘real’ landslide hazard areas due to vast area

of

potential danger zones

About 40% of Seoul and 60% of Busan classified as potential danger

zones

Landslide damages frequently occurring outside of dander zones previously

identified using empirical-statistic models [usually weighting methods]

Problems with landslides in Korea

Increase of

Landslide areas

Seoul40%

Busan60%

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Empirical-Statistic model : previous method Physics-based model : our maps

Landslide hazard map

Limitation of existing empirical-statistic model : Seoul 2011

☞ Empirical-statistic model do not consider groundwater!! Most dangerous area is classified as safe area!!☞ Debris avalanch due to landslide occurred in the circled area killed 3 people in notorious Woomyon Mt. disaster on July 27, 2011 in Seoul!!

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Our new maps

Accurate prediction of landslide hazard areas [Woomyon Mt. in Seoul]

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Empirical-Statistic model : previous method Physics-based model : our maps

Landslide hazard map

Limitation of existing empirical-statistic model : Busan 2009

☞ Empirical-statistic model do not consider groundwater!! Most dangerous area is classified as no threat zone!!☞ Debris avalanch due to landslide occurred in the circled area killed 1 people in the apartment on July 16, 2009 in Busan!!

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Our new maps

Accurate prediction of landslide hazard areas [Busan 2009]