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DRC Project: LANDSLIDE DISASTER IN VIETNAM Dr Nguyen Thi Thu Ha Vietnam National University, Hanoi LECTURE CONTENT I INTRODUCTION II OVERVIEW OF LANDSLIDE DISASTER IN VIETNAM III THE CASE STUDY OF VULNERABILITY ASSESSMENT OF LANDSLIDE DISASTER IN BACKAN PROVINCE TH LECTURE ON JULY 2013 I INTRODUCTION II OVERVIEW OF LANDSLIDE DISASTER IN VIETNAM - Past and ongoing researches on landslide in VN - Landslide disasters distribution - Landslide types - Causes - Mitigation I INTRODUCTION The term "landslide" describes a wide variety of processes thatdisaster” result in the downward and outward The “landslide is the specific term of movement of vulnerable slope-forming materials including rock, landslide that to residential lives, goods soil,destroyed artificial fill, or a combination of these and infrastructures The materials may move by falling, toppling, sliding, spreading, or flowing (table below) Types of landslides Abbreviated version of Varnes' classification of slope movements (Varnes, 1978) Where is Vietnam & Why is Vietnam’s landslide? ¾ national land area is highland (85% lower than 1000 m; 1% >2000 m) Red River Delta Complex geologic structure + tropical climate thick and unconsolidated weathering crust Tropical climate: high occurrence frequency of heavy rain and Japan storms/typhoons Undeveloped economics, low technology and public awareness high vulnerable to disasters Vietnam Estimation: 15 landslide disaster/year with 30 people dead/year, ITST Mekong River Delta February 2012 am 16Feb2012, No Highway, Mai Chau, Hoa Binh Province 2deads, traffic blocked for 10 days April 2012 am 15Apr2012, Phan Me coal mine, Thai Nguyen Province destroyed 14 houses and 7deads May 2012 5May2012, Nui Cam, An Giang (Southern Vietnam) Rock fall, deads July 2012 26-27Jul2012, Northern Mountainous Areas destroyed many houses, roads, schools and 11deads August 2012 11 am 6Aug2012, No34 Highway, Nguyen Binh, Cao Bang 31Aug2012 night, Xat Bat, Lao Cai people dead 10 people dead, destroyed 12 houses In future, landslides will occur more frequently with higher intensity in Vietnam - Vietnam is a Southeast Asian country where landslides occurred frequently and in diversiform; Landslide disasters damaged seriously residential lives, livelihoods and infrastructures; - Vietnam is a country most impacted by climate change This impact was exposed by increasing in intensity and occurrence frequency of natural disasters, including landslides Landslide disaster in Vietnam gives a typical lesson for the disaster in ASEAN countries where: Therefore - most areas are featured by sloping terrain and complex geologic structures; - socio-economics, technology are underdeveloped impact and mitigation of disaster are distinguished II OVERVIEW OF LANDSLIDE DISASTER IN VIETNAM - Past and ongoing researches on landslide in VN - Landslide types - Landslides’ distribution and state - Landslides’ incidence and susceptibility - Landslides’ causes - Mitigations Past and ongoing researches on landslide in VN 2010– present: 2000 – 2010: Natural hazards/disasters (landslides) are getting and international NGO’s investment and research and assessment of landslide s in a broad scale government’s (regional and national scale) , Institute of Geological 1990 – 2000: scientific interests Ongoing National Project and zoning of D focused onVietnam small-scale landslides inresearches: mountainous area, e.g.: Lai“Investigating, Chau (Minh assessment V risk C etassessing al., 1994); Son La (Tuyet Sciences, Academy of Science and Technology: Project “Integrated of geohazards in landslide in 37 mountainous provinces in Vietnam” (MONRE); Development Landslide Riskmapping Assessment Vietnam and mitigations” (2000-2003); National programme on “Vietnam natural of hazards zoning “ et al., 1991; 2000); Dak Lak (Du D K et al, 1994), Central highland (Yem N.T et al, 1992) Significant outcomes: alongmaps Transport Arteries in Nam and (JICA, Tohoku (TGU) and VMOT); (2003 Technology – 2006) series of geohazards in Viet Vietnam pilot sites Gakuin at scaleUniversity of 1:50.000; landslides of Ho land subsidence zoning map, scale 1:2.000.000 (Son N T et al., 1996); landslide risk possibility zoning map for “Capacity Building Mitigation and Hochiminh Adaptation branch of Geodisasters Related to Environment Energy Chi Minh road talus (2005for – 2009) by VNU, landslide distribution and state and , main the Northern West region; the Northern East region; Collaboration Central highland regionVNU) at scale of 1/500.000 territorial in Vietnam” (Vietnam – Norway project, causes,Development technical mitigations planning, unpublished data, ministerial storages Landslide research challenges in Vietnam: - Lack of published and exchanged data - Lack of modern methods and techniques - Almost researches are theoretical approach/ inapplicable approach - Mitigations are not concrete Promising research topic in Vietnam Landslide types Northern Mountainous Area 60-70 Rock mines (Central part) 5-10 10-20 Northern Mountainous Area 1-5 Hanoi, Vinh Phuc, coal mines Keller A., 2011 Slides: - Small scale: widespread in Northern and Central mountainous area, particularly along the roads (transport arteries) - Medium scale (100 - 1000 m ): in mining areas (tailings, soil-dumps) Quang Ninh 2011 - Large scale (>1000 m ): debris flows Ha Giang, 7/2008 Hai Van mountain-pass, No Highway Yen Bai, 2012 Phan Me, 2012 Cho Ra, Bac Kan Province Flows: accompanied with flash floods and heavy rains Falls: rock mines Subsidence: Road, Karst 6/2013 Thanh Hoa Quang Nam, 2011 8/2012 Hanoi, Phu Tho 4/2012 Quang Ninh, 1/2011 Ha Giang,Da 6/2012 Nang 9/2011 Landslides’ distribution and state Very high Residential areas: Mountainous residential districts (Son La, Lai Chau, Yen Bai, Ha Giang), accompanied with flash floods Main type: debris flow Reservoirs areas: Hoa Binh, Son La, Central Highland, medium scale, all medium types Mining areas: rock mines (Thanh Hoa, Nghe An, Da Nang); coal mines high (Quang Ninh, Thai Nguyen), gold and other metals (Yen Bai, Hoa Binh, Bac Kan) Main type: falls, subsidence Along transport arteries: along No 6, No (Hai Van), along Ho Chi Minh road, along No 4, No high ways Main type is Slides at small scale low Landslides’ incidence and susceptibility - 35 people dead/year (excluding by debris flows) - Hundred houses destroyed/year - Hundreds road kilometers were destroyed/year, many bridges and underground projects were damaged - Huge budget amount for landslide disasters recovery - Residential/social mentality Ho Chi Minh city, 2010 The dead by landslide in Quang Nam, 2009 Ho Chi Minh road Damage to residences from landslides in Son La, Son La Province, Vietnam Landslide on National Highway No (in Central Vietnam) Landslides disasters’ causes Geologic structure and processes: deep and active faults, thick and strong deformed rock formations Topographic structure: slope steep Climate: tropical, warm and heavy rain Policy: weak, focus on economic development only Awareness and culture: low, minority groups Technology: undeveloped Mitigations Inappropriate technology Monitoring and Early Warning: No Policy and investment: beginning; Public awareness: beginning; Hazard Mapping, Vulnerability and Risk Assessment: beginning Capacity Building: beginning Mitigation, Preparedness and Recovery: inappropriate CONCLUSION Landslide is phenomena that happens often in Vietnam Recently, landslide disaster has been taken place in VN frequently and threatened residential lives, goods, livelihoods and socio infrastructure Landslide in Vietnam is forecasted to increase in occurrence frequency, intensity, and impact due to the impact of climate change Identifying a sustainable framework to mitigate the disaster risk is going to start now > need more high technology and management transfers and lessons Homework: What you think about landslide disasters in Vietnam? Which of following mitigations should be the first priority to mitigate the risk of landslide disasters in Vietnam? Why? A - Investment in technology/engineering B - Public Preparedness and Recovery awareness rising C - Research capacity building D – Planning improvement Please write answer in a A4 page and send me (cc: Prof Ohtsu) by email: thuhageo@gmail.com before 16Jul Deadline: 15 Jul ... OVERVIEW OF LANDSLIDE DISASTER IN VIETNAM - Past and ongoing researches on landslide in VN - Landslide disasters distribution - Landslide types - Causes - Mitigation I INTRODUCTION The term "landslide" ... mitigation of disaster are distinguished II OVERVIEW OF LANDSLIDE DISASTER IN VIETNAM - Past and ongoing researches on landslide in VN - Landslide types - Landslides’ distribution and state - Landslides’... and investment: beginning; Public awareness: beginning; Hazard Mapping, Vulnerability and Risk Assessment: beginning Capacity Building: beginning Mitigation, Preparedness and Recovery: inappropriate