1. - 1 - 육군사관학교 Korea Military Academy 자연재해저감기술개발사업단

2. - 2 - How to develop precision landslide hazard maps? Contents 22 Let us explore landslide hazrd maps!! 33 What are the problems with landslides? 11 How to use landslide hazard maps? 44

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4. - 4 -  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 Seoul 40% Busan 60%

5. - 5 - Empirical-Statistic model : previous methodPhysics-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!!

6. - 6 - Our new maps Accurate prediction of landslide hazard areas [Woomyon Mt. in Seoul]

7. - 7 - Empirical-Statistic model : previous methodPhysics-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!!

8. - 8 - Our new maps Accurate prediction of landslide hazard areas [Busan 2009]