2014 Summer training course for slope land disaster reduction Taipei, Taiwan, Aug

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1 MINISTRY OF SCIENCE AND TECHNOLOGY HYDROTECH RESEARCH INSTITUTE MINISTRY OF NATURAL RESOURCES AND ENVIRONMENT VIETNAM INSTITUTE OF GEOSCIENCES AND MINERAL RESOURCES (VIGMR) 2014 Summer training course for slope land disaster reduction Taipei, Taiwan, Aug PROJECT REPORT SON LE MINH CHANH PHAM VIET

2 Vietnam Introduction Vietnam is located in the center of the Southeast Asia, and is shaped like the letter "S". The country lies in the eastern part of the Indochina peninsula, bordered by China to the north, Laos and Cambodia to the west, and the East Sea and Pacific Ocean to the southeast. Vietnam's coast line is 3,260 km long and its inland border measures 3,730 km. Vietnam has a population of more than 90 million people, comprised of 54 different ethnic groups that possess historically rich cultural backgrounds and interesting folk arts. The country has more than 1,000 historical, cultural, and architectural sites which have been officially classified as "Heritage Sites". Five of these sites have been recognized as world cultural heritage sites by UNESCO (United Nations Educational and Scientific Cultural Organization), including Halong Bay, Phong Nha - Ke Bang National park, the ancient capital of Hue, the ancient town Hoi An, and My Son Holy Land

3 Vietnam Introduction Vietnam is located in the tropical monsoon area, one of the storm-prone areas in the Asia Pacific region. Typhoon usually accompany with high tide and heavy rain, thus resulting in heavy and long rains, causing various types of natural disasters, especially landslides, flash flood, debris flow in hilly and mountainous areas. Hills and mountains in Vietnam cover 3/4 of land area, therefore approximately 70% of the mountainous areas in this country (37/63 provinces and cities) have been annually affected by landslides (debris flow, flash floods). This type of natural disasters have been increasingly severe in terms of magnitude, frequency and volatility, causing vast losses in human life, property, socio-economic and cultural infrastructure as well as environmental

4 LANDSLIDE IN VIET NAM Landslides burried 23 people in Sung Hoang village, Phin Ngan commune, Lao Cai province in 9/2004. A large landslide (~ m 3 ) burried 19 people in Mu Cang Chai in 2012 during a heavy rain A large landslide (~ m 3 ) block a national highway in Hoa Binh in 2012, ~ 10 days after a series of long duration rains A small landslide burried 6 people of a family in Lao Cai in 2012 after > 10 raining days

5 FLOOD, FLASHFLOOD, DEBRIS FLOW IN VIET NAM people killed, missing by typhoon Nari, On 09/30/2013, Wutip typhoon : 9 people dead, 199 people injured, damage trillion /2011, floods in middle of Viet Nam: 55 died. Floodwaters have submerged about 170,000 homes and 23,700 hectares of crops /2010, torrential rains, the water floods up "super speed" unprecedented in 100 years submerged in sea water Huong Khe district, Ha Tinh province. 5. In 2008, floods in Lao Cai province, 144 dead and missing. 6. 8/1996, Niki storm in the North, 65 people dead and missing in the North of Viet Nam 7. 7/1986 floods, 121 dead in mountainous regions North of Viet Nam

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7 Statistics of flash floods, debris flow from 1958 to 2004 in Viet Nam >

8 MINISTRY OF NATURAL RESOURCES AND ENVIRONMENT VIETNAM INSTITUTE OF GEOSCIENCES AND MINERAL RESOURCES (VIGMR) Investigation, assessment and warning zonation of landslides in mountainous regions of Vietnam From 2012 to The government s project

9 OBJECTIVES AND TARGETS 1. Defining the current situation, causes and effects, warning zonation of landslide hazards in the Vietnamese mountainous areas, recommendation of measures for prevention, preparedness and mitigation; 2. Establishing a standard national database on landslides as a scientific base to improve the capacity building in disaster warning and preparedness, for the planning and sustainable development in the mountainous areas of Vietnam; 3. Creating an atlas of warning zones for landslide hazards in mountainous areas from the Central level to community level; 4. Determining a scientific foundation for setting up a network of observation and monitoring station for early warning of natural disasters in general and of landslides in particular in the Vietnamese mountains; 5. Designing an early warning system for landslide hazard and installing a pilot network of observation and monitoring stations in some typical areas.

10 IMPLEMENTATION PHASES AND DURATION 1. Phase I: (4 years): - Investigation and warning zonation of landslide hazards in 17 Northern mountainous provinces - Implementation of a pilot network for landslide hazard observation and monitoring stations at high hazard locations. 2. Phase II (3 years): - Investigation and warning zonation of landslide hazards in 13 Central, 5 Highland and 2 Southeastern mountainous provinces; - Detail investigation at large scales (1/ to 1/2000) for high hazard areas; proposal of landside early warning system in 17 Northern mountainous provinces. 3. Phase III (4 years): - Detail investigation at large scales (1/ to 1/2000) for high hazard areas and installation of landside early warning system in the Central, Highland and Southeastern mountainous provinces.

11 Landslide inventory maping for 10 northern provinces ( ) 1. Inventory from historical records 2. Image interpretation (Stereoscopic aerial photographs) 3. Field investigation

12 Landslide inventory map

13 Case study Xop Mat village is about 183 km to the west from Vinh City, Nghe An province and about 400 km away from Hanoi (Tuong Duong District). XopMat village DEM of Tuong Duong Landslide occurs after heavy rains on 11/06/2011

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15 FACTORS TRIGGER Geological condition: Ca River Formation, lower Subformation (O 3 -S 1 sc 3 ): Slate quartz sericite, sericite schist, sandy siltstone, sandstone, medium grain small. Because of the active fault zone that runs along the Nam Non springs were crushed rocks, compression and break strongly. The cracked on the top create conditions for water infiltration into the sliding surface lubrication effect and reduces the shear strength of the soil caused movement. Topography - geomorphology: regional topography slopes from 130m altitude up to 250 m altitude is 35 o -40 o. Rainfall: >200mm/2days.

16 Monitoring and Early warning System o Inclinometers o Piezometers o Extensometers o Rain gauge o Water level sensor

17 MINISTRY OF SCIENCE AND TECHNOLOGY HYDROTECH RESEARCH INSTITUTE MINISTRY OF NATURAL RESOURCES AND ENVIRONMENT VIETNAM INSTITUTE OF GEOSCIENCES AND MINERAL RESOURCES (VIGMR) THANKS FOR YOUR ATTENTION 2014 Summer training course for slope land disaster reduction Taipei, Taiwan, Aug