Landslides Causes & Impacts

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LANDSIDE HAZARD IN MUZAFFARABAD, AZAD KASHMIR

CAUSES & IMPACTS

(A case study of village Dhanni)

Nasir HameedSiratuallah

Nadir Mahmood

Supervised by: Prof. Dr. Mahmood-ul-Hassan


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Landslides, defined as the mass movement of rock, debris or earth

down a slope (Cruden, 1991).

Landslides form a significant component of the natural hazards that

affect most of the hilly regions round the globe. Recent studies on

global landslide disasters indicate that some of the highest risklandslide disaster zones are located in Colombia, Tajikistan, India,

Pakistan, China, and Nepal where the estimated number of people

killed per year per 100 sq. km area was found to be more than one.

It has also been observed that casualties resulting from landslides

hazards are not evenly distributed throughout the world, but are

more concentrated in developing countries, partly due to their

higher population densities and lack of preparedness.

Introduction:


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Source: NDMA

Risk Assessment Matrix for Azad Jammu & Kashmir


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Source: Dunning et al, 2006Hattian Bala rock avalanche, >1000 fatalities, 2005 earthquake.


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Justification of study:

Landslides in the study area are recurrent phenomena which causelosses of life and property, damage to natural resources and

infrastructure including roads, bridges, telephone / electric lines etc.this leads immobility of goods and services leading to huge loss ofrevenue to the government.

In order to reduce the losses, this study has been carried out to put

forward suggestions for the mitigation of landslide hazards.


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Research Objectives:

Followings are the objectives of the study:

To map the landslides in Muzaffarabad and the surrounding area.

To identify the major causes of landslides in the study area.

To study the impacts of landslides in the area.

To prepare the Landslide Hazard Zonation map of Muzaffarabad


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DATA

Primary data

Questionnaire survey Field survey

People perception,

About causes, impacts

General observations

(Photography) Field survey

Causes and impacts

inflicted by Landslide

Secondary data

Satellite Images

(2.5 meters)AKMIDC Department,Muzaffarabad GoAJK

Thematic layers , Rasteranalysis e.g, DEM & LSHZ

Digital Elevation Model

(DEM) 30 metersUnited States GeologicalSurvey (USGS) website

Slope, Aspect, Contours,Relief maps,

Topographical Sheets 43 F7

& 11 at 1:50,000 ScaleLand Use Planning Dept,

Muzaffarabad GoAJK.

Layers e.g, settlements

roads, hydrology, etc

Geological Sheets

43 F7 & 11 at 1:50,000 ScaleNCEG, University ofPeshawar, Peshawar

Lithology, Faults etc

High resolution images Google earth

Detail investigation of thestudy area

Research articles, Reports Internet, Institute s library

Causes and EffectsLSHZ

Climatic dataMeteorological Department,

Muzaffarabad, GoPK.

Rainfall and temperature

of study area

Damages data, DCRDeputy commissioner

Office, Mzd. AJK

Landslide effects,

Population statistics

Data collection techniques, their purpose and sources:

Key:

Data utilized

Purpose

Sources


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Data

analysisSoftware

ArcGIS

package

Digitization

Raster

analysis

3D

visualization

MS. Officepackage

Tabulation

Description

Presentation


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SPATIAL DISTRIBUTION OFLANDSLIDES AROUND MUZAFFARABAD


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Study area

general Introduction

Absolute location: Latitude3424'6.978"N to 3424'6.881"N

Longitude

7328'8.73"E to 7329'14.49"E

Area: 5 sq.km

Elevation: 2,700 feet

Population: 1,244 (projected 2010 from DCR 1998)

Avg. annual rainfall: 1363 mm (Met. Dept, Mzd)

Temperature: Mean minimum (January) 2.65 oC

Mean maximum (June) 36.75 oC

Geology: Muzaffarabad formation (Lime stone, dolomite)

silt, sand, gravel


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Pirchinasi9560 feet

Muzaffarabad2200 feet

River Jhelum

River Neelum

Domel

Physiography of the study area


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Bird eye view Village Dhanni

Image Source: Google Earth


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Major natural causes of landslides in the study area

Active seismicity Llithology and faults

Slope

Rainfall

Hydrology

Aspect


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50.0

18.6

10.0

5.77.1

5.72.9

0.0

10.0

20.0

30.0

40.0

50.0

60.0

P

ercentage

Causes

Respondents perception about causes of landslides

Source: Questionnaire survey


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Respondents response regarding season of occurrence of landsliding


27

7

63

3

0

10

20

30

40

50

60

70

Winter Spring Summer Autumn

Percen

tage

Season


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Plate boundaries in the South Asian region

Source: Encarta atlas


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Pre earthquake image

of the study area (2002)


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Post earthquake image

of the study area (2010)


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Name of Formation Lithology

Murree Formation Sand Stone, Silt Stone, Shale, with subordinate

intra formational conglomerate and lenses oflimestone

MZD Formationhard, rubbly Limestone & Dolomite, Few parts of

it also contain carbonaceous limestone and shale horizons

Hazara Formation Argillite, Slate, Phyllites, and Siltstone

overlaid by gypsum and limestone units.

Surficial deposits Loose Clay, Silt, Sand & Gravel

Kamlial FormationLimestone & Calcareous Shale with intercalations

ofMarl & Limestone

Stream Channel

/Alluvial depositsSilt, Sand & Gravel

Terrace deposits Gravel, Sand, Silt & Clayey material

Map digitized from GSP- sheets


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Crack developed in the material because of weak material lying on steep slope

Source: Field study


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Source: Field studyCracks accelerate the downslope movement of mass at the site.


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Source: USGS 30 m DEM


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0

500

1000

1500

2000

2500

2001 2002 2003 2004 2005 2006 2007 2008 2009 2010

Rainfall(

mm)

Years

Source: Meteorological Department, Mzd. AJK

Note: Muzaf farabad receives 1363mm average annual rainfall

Annual Rainfall (2001-2010)


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0

50

100

150

200

250

300

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

Rainf

all(mm)

Months

Mean monthly rainfall (2001-2010)

Source: Meteorological Department, Mzd. AJK


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Source: Google Earth

Neelum Riverfound responsible for undercutting slopes, a major cause of landsliding in the area.


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Source: Google Earth

Undercutting of slopes could be observed at different locations along the river.

Houses at risk at the top of slope.


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Source: Field studyDhanni Nala along the study area contributes to slope instability


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Source: Field study

No engineering measures observed to prevent undercutting of slopesSoil erosion could also be seen.


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Source: USGSLandslides are more at south facing slope, attributed to

windward direction during monsoon rainfall.

Aspect study area


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Major anthropogenic causes of landslides in the study area Devegetation

Road construction

Human induced vibrations


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Landslides due to road construction at front face of the study area.Source: Field study


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Source: Field study

Road construction found as dominant factor for slope instability at different locations in the area.


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Source: Field studyRapid devegetation contributes to prompt mass movement at many

locations in the area.


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Source: Field studyDeforestationfound responsible for instability of slopes in the study area.


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Source: Field studyReckless cutting bared the slopes, in the past the whole area was

under thick forest cover (Elders of the study area)


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Source: Field study

Human induced vibrations a contributory factor for slope instability

found during field study.


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Major Impacts of landslides in the study area

C lti d t E th k Di t


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Deaths Injured

Earthquake Related 247 125

Landslide Related 39 11

0

50

100

150

200

250

300

Numbers

Casualties due to Earthquake Disaster

of 2005 in Dhanni Village

Source: Deputy Commissioner off ice, Muzaffarabad


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Respondents response: Life & property damages by landslides after Earthquake 2005


79

21%

%


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EQ Related Landslide Related

Houses 135 9

Shops 5 7

0

20

40

60

80

100

120

140

160

Numbers

Source: Deputy Commissioner off ice, Muzaffarabad

Houses & Shops damage due to Earthquake Disaster

of 2005 in Dhanni Village


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(Source: Field study)Remains of the houses could be seen at margins of the terrace


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Source: Field studyAlmost all the housescollapsed at the margins of the village

during earthquake, 2005.


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Source: Field study

No land use regulations found in the study area. People still make

encroachment towards marginal lands.


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Source: Field studyAgricultural land losses are common phenomena in the marginal lands.


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Image courtesy : Mumtaz Hussain, AKMIDC

Old bridge has collapsed during the earthquake

of 2005 due to landsliding. A new bridge isunder construction that will reduce miseries of

the inhabitants that they are suffering since

more than 5 years .

(Source: Field survey)

Source: Field study


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Cable lift:

The only source to cross the river since

more than 5 years is the cable lift.

Source: Field study


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Ladslide Hazard Zonation (LSHZ) forMuzaffarabad


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Susceptibility Class Area (acres)

Low 2137Moderate 7197

High 6446

Very high 5051

10.25

34.54

30.97

24.24

Low Moderate High Very High

Shwoing Susceptibility classes % to total study area

Class

Findings & Recommendations.


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This study shows that if the landsliding and soil erosion phenomena were not

checked, the Dhanni village surrounded on three sides by the Neelum river

will ultimately be washed away from the surface.

Beside natural factors this study reveals that one of the main cause of the

landsliding is the Deforestation in the area. To reduce the frequency of sliding

deforestation should be checked strictly by the government.

Implementation of Land use regulations and Engineering measures

Awareness should be created amongst the people to avoid the sites for the

construction of houses and other installations that are vulnerable to landslides.

Establishment of Centre for Environmental Studies (particularly for landslides)

In earth science institutes.

Lack of coordination between researches and decision-making personnel in

different government and non government organization should be curtailed.

Micro hazard zonation mapping of the area


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Landslides Causes & Impacts

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