LANDSLIDE DISASTER IN VIETNAM

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 9 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

5 am 16Feb2012, No. 6 Highway, Mai Chau, Hoa Binh Province
2deads, traffic blocked for 10 days


April 2012

5 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, 6 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
2 people dead
10 people dead, destroyed 12 houses


September 2012

9 am 7Sep2012, Mu Cang Chai, Yen Bai Province
29 people dead


October 2012

27-28Octo2012, accompanied by Son Tinh Typhoon
1 people dead, landslide occurred along Ho Chi Minh talus road


Land Subsidence

•

Coal mine in Quang Nam: 2 dead (24/4)

•

Coal mine in Quang Ninh: 1 dead, (21/5)

•

Rock mine in Nghe An: 1 dead, 7 injured (4/7(

•

Gold mine in Tuong Duong, Nghe An: 3 dead, 7 injured

Quang Nam

(17/7)

•

Coal mine in Quang Ninh: 3 dead, 4 injured (23/7)

•

Hydropower cellar in Nam Pong, Nghe An: 1 dead, 6 injured
(19/8)

•

Metal mine in Yen Bai: 17 dead, 3 injured (7/9)

•

Rock mine in Ha Tinh: 1 dead (19/9)

Ha Tinh


Vietnam is one of the most vulnerable countries to the impacts of
climate change. Vietnam loses around 2 per cent of GDP per year as a
result of weather-related disasters. In 2011, natural disasters
Typhoons
occurrence
frequencyand infrastructure with
continued to impact
on Vietnamese
livelihoods
flooding of around 450,000 households, inundation of more than

events

350,000 hectares of rice paddy field, and 295 recorded deaths, with an

landslides
Extreme rainfall increase, even in areas whereMore
total rainfall
decreased
Number of days with Rx ≥ 50 mm (heavy rainfall day)

occurred

estimated damage bill of USD 620 million.

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).

-

3
Medium scale (100 - 1000 m ): in mining areas (tailings, soil-dumps).
Quang Ninh 2011

-

3
Large scale (>1000 m ): debris flows.

Ha Giang, 7/2008

Hai Van mountain-pass, No. 1 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. 1 (Hai Van), along Ho Chi Minh
road, along No. 4, No. 2 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. 1 (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