Akrur Singh Mahat

070MSD/352

Supervisor

Prof. Dr. Jiba Raj Pokharel

Ast. Prof. Inu Pradhan Salike

Introduction Study Area :

Rationale of the Study

Landslide hazard change,degrade,destroy heritage site-adverse Impact to OUV

High Frequency of landslide occurrence in PMZ.

Most of the Damage Monuments around the Landslide Area.

Human induce and Natural Cause both present

No Landslide study/Risk Reduction Plan

Risk to inscribe the Kathmandu Valley on the List of World Heritage in Danger.

Limitation

• Recent topographical map is unavailable.

• Detail geological map of the study area is unavailable

• Important outcrops of the study area lying at cliffs east

side of Bagmati at Suryaghat could not be accessed.

• Study limited to the risk related to Landslide and do not

consider other hazards.

• Only Physical vulnerability of Monuments is consider.

• Attributes taken for vulnerability assessment are limited

to traditional monuments

Objective

Overall Objective:

Landslide Risk Reduction Plan

Specific Objectives:

To prepare Landslide Hazard Map.

To Find the Heritage value of Monuments.

To Find the State of Conservation of Monuments.

Landslide Risk Assessment of PMZ.

To prepare Landslide Risk Reduction Plan of Action

Literature Review

Landslide Hazard Assessment (Landslide Susceptibility Analysis)

Bivariate analysis

(Dependent & Independent Variable)

(Van Westen 1997)

Frequency Ratio Method

LSI = Fr1+Fr2+…..+Frn

(Lee et al 2006,DMG,2013)

Statistical-index method

wij = ln (fij/f) = ln ((A*ij/Aij)*(A/A*))

= ln ((Aij*/A*) * (A/Aij))

Literature Review…

Assessing state of Conservation (Lazzari et al,2009)

Assessing Heritage Value Relationship between Attribute, Indicators and Value (Rits-IOE ,2012)

Vulnerability Assessment

Parameters used to cultural heritage features (Canuti et al.2009)

1. Geometric properties 2. Presence of restoration works 3. Presence or absence of coverage

(roof) 4. Presence of cracks 5. Presence of strain processes 6. Presence of humidity biological

degradation

Literature Review…

Relationship between Hazard, Vulnerability and Disaster (source:ICCROM,2010)

Risk (R) = Hazard (H) x Vulnerability (V)

S.N. Method Principle

1 Qualitative Based on risk class categorized by expert judgment. Risk class:High,

Moderate and low

2 Semi-

quantitative

Based on ranking and weights assignment by a given criteria. Risk

index: ranked values (0-1,0-10 or 0-100)

3 Quantitative Based on probabilities or percentage of losses expected. Risk value

probabilistic value (0-1) over certain amount of monetary or human loss

Method of Risk Assessment (Chowdhaury and Flentje,2003)

Risk Assessment Matrix (Alcaraz Tarragüel et al. 2012)

Methodology

Base Maps Factor Maps

Lithology map

Slope map

Aspect map

Elevation map

Land use map

Drainage distance map

Landslide distribution Map

Cross Tabulation

Weight calculation

(Frequency Ration

Method)

Overlay of factor map

Landslide Susceptibility

Map

Classification of

Hazard Map

Hazard Class

High

Moderate

Low

Landslide

Hazard Map

Susceptibility Validation

Data Input

Risk Map

Cultural Heritage

Element at

Risk(Monuments)

Heritage value/ State

of Conservation

Calculation

Vulnerability

Map

Recommendation

Plan of Action

Local Knowledge/Literature

review/Field Obs.

Existing Mng.Plan /Prog.

Improvement

Strategy

Overlay of

Hazard and

Vulnerability

Reclassification of

factor map

Susceptibility

Validation

Schematic Flow Diagram of the Overall Study

Methodology… Conceptual Framework

Landslide Risk Reduction Plan

Risk Assessment

Heritage Value (HV)

Landslide Hazard Heritage Vulnerability

State of Conservation (SOC)

Landslide Inventory

Indicator: 1. Slope Aspect 2. Slope Angle 3. Elevation 4. Drainage 5. Geology 6. Land Use

Weighting

Landslide Hazard Map

Landslide Risk Map

Indicator: 1. Historic 2. Aesthetic 3. Livingness 4. Ecological

Indicator: 1. SD 2. MD 3. LoMD

Weighting Weighting

HV Map SOC Map

Heritage Vulnerability Map

Continue next page

Cost Estimation of Landslide Risk Reduction

Methodology…. Conceptual Framework…

Cost Estimation of Landslide Risk Reduction

Landslide Inventory

Monument Restoration Landslide Stabilization

Landslide Hazard Map

Typology A. Temple B. Sattal/Pati C. Open Space

Plinth Area Rate

Cost for Monument Restoration

Cost Estimation of Landslide Risk Reduction

Landslide Class/Area

Landslide Hazard Class/Area

Details of Stabilization works

Details of Environment Restoration works

Unit Area Rate for Low, Medium, High

Unit Area Rate for Low, Medium, High

Monument Sample=290 Preliminary Inventory

SOC

Mode of Intervention

Plinth Area of Monument

Cost for Landslide Cost for Landslide Susceptible Area

Cost for Landslide Reduction

Landslide Risk Reduction Plan of Action

Monument Survey Firm:Monument Vulnerability

Methodology…

Landslide Hazard Mapping Results & Discussions

Results & Discussions…

Various Factor Maps and their frequency ratio

Sq.m. Sq.km. % Cell area Sq.Km. % Frequency

Slope

Aspect 1 N 1116 111600 0.112 11.18 1600 0.002 9.41 0.84

2 NE 1098 109800 0.110 11.00 2600 0.003 15.29 1.4

3 E 1170 117000 0.117 11.72 2300 0.002 13.53 1.16

4 SE 1453 145300 0.145 14.55 2500 0.003 14.71 1.01

5 S 1468 146800 0.147 14.70 2300 0.002 13.53 0.92

6 SW 1420 142000 0.142 14.22 1900 0.002 11.18 0.78

7 W 1263 126300 0.126 12.65 3100 0.003 18.24 1.45

8 NW 910 91000 0.091 9.11 700 0.001 4.12 0.45

0 FLAT 87 8700 0.009 0.87 0.01 0.000 0.00 0

Total 998500 0.999 17000 0.017

Slope

angle 1 > 5 3951 395100 0.395 39.57 400 0.000 2.35 0.06

2 5-15 3285 328500 0.329 32.90 5100 0.005 30.00 0.91

3 15-25 1591 159100 0.159 15.93 5100 0.005 30.00 1.91

4 25-35 726 72600 0.073 7.27 2900 0.003 17.06 2.4

5 35-45 309 30900 0.031 3.09 2100 0.002 12.35 4.21

6 >45 123 12300 0.012 1.23 1400 0.001 8.24 7.42

Total 998500 0.999 17000 0.017

Elevation 1 <1300 125 142400 0.142 14.26 200 0.000 1.18 0.08

2 1300 - 1320 4646 379000 0.379 37.96 5700 0.006 33.53 0.88

3 1320 - 1340 3790 464600 0.465 46.53 11100 0.011 65.29 1.41

4 >1340 1424 12500 0.013 1.25 0.01 0.000 0.00 0

Total 998500 0.999 17000 0.017

Drainage

Distance

1 < 25m 4441 444100 0.444 44.42 13000 0.013 76.47 1.74

2 25-50 m 2350 235000 0.235 23.50 2100 0.002 12.35 0.52

3 50-100 m 2324 232400 0.232 23.24 1900 0.002 11.18 0.48

4 > 100 m 883 88300 0.088 8.83 0.01 0.000 0.00 0

Total 999800 1.000 17000 0.017

Geology

1 Terrace Sand 7302 730200 0.730 73.12 14300 0.014 84.12 1.15

2

Lower

Terrace

Sand 1323 132300 0.132 13.25 0.01 0.000 0.00 0

3

Rock

(Calcareous

Sandstone) 997 99700 0.100 9.98 2700 0.003 15.88 1.61

4 ? (Water) 364 36400 0.036 3.65 0.01 0.000 0.00 0

Total 998600 0.999 17000 0.017

Landuse

1 Cultivation 1012 101200 0.101 10.13 600 0.001 3.53 0.34

2 Builtup area 2045 204500 0.205 20.46 0.01 0.000 0.00 0.00

3 Grass 1444 144400 0.144 14.45 0.01 0.000 0.00 0.00

4 Forest Area 5055 505500 0.506 50.58 16100 0.016 94.71 1.90

5 Building 85 8500 0.009 0.85 0.01 0.000 0.00 0.00

6 River 354 35400 0.035 3.54 300 0.000 1.76 0.49

Total 999500 1.000 17000 0.017

ClassS.N.Factor

Pixels Landslide

Cell AreaTot.no

Results & Discussions…

Various Factor Maps and their Frequency Ratio

Results & Discussions…

The Percentage distribution of the susceptibility classes and landslide occurrence

Percentage Distribution of Hazard Zone

Susceptibility Validation

0.00

10.00

20.00

30.00

40.00

50.00

60.00

70.00

80.00

90.00

100.00

0.00 20.00 40.00 60.00 80.00 100.00

Frequency Ratio

Statistical Index

AUC-is 84.19%

Results & Discussions…

Result Results & Discussions…

Results & Discussions…

Class Count

High 141

Medium 135

Low 14

Total 290

Heritage Value

Class Count

High 49

Medium 66

Low 175

Total 290

State of Conservation

Results & Discussions…

Result

Risk Assessment Matrix

Risk Matrix (quantitative)

Vulnerability

Low Medium High

Hazard 1 2 3

Low 1 1 2 3

Medium 2 2 4 6

High 3 3 6 9

Risk Matrix (qualitative)

Vulnerability

Low Medium High

Hazard 1 2 3

Low 1 Low Low Medium

Medium 2 Low Medium High

High 3 Medium High High

Results & Discussions…

Risk Assessment Matrix

Class Count

High 32

Medium 236

Low 22

Total 290

Vulnerability of Monuments

S.N.Level of

Landslide Risk

No of

Monuments

1 High 15

2 Medium 109

3 Low 166

Total 290

Monuments in Landslide Risk

Results & Discussions…

Results & Discussions…

Level of Risk High Medium Low

Priority P1 P2 P3

1 Monument Restoration 85.1 737.06 1012.84 1835

2 Landslide

2.1 Landslide Stablization 38.87 4.58 111.98 155.43

2.2 Hazard Area Conservation 88.68 36.96 32.25 157.89

Total for Landslide 127.55 41.54 144.23 313.32

Total 212.65 778.6 1157.07 2148.32

Say 213 779 1158 2150

Total

Estimated Cost for Action Plan

(NRS in Million)

Conclusions and Recommendations

Conclusions and Recommendations…

Plan of Action

Conclusions and Recommendations… 3)Plan of Action

General Plan of Action

Specific Plan of Action

Plan of Action…

Conclusions and Recommendations…

Plan of Action…

Recommendation for future Research

1. Geological and topographical survey and investigation.

2. Multi-hazard Risk Assessment of PMZ.

3. Site Response Analysis of Slesmantak Forest.

4. Risk Management of Mass gathering at Special Events.

1835

Conclusion

• Landslide Hazard -High(15%),Medium (31%) • Out of 290 Monuments, 5% (15 nos) are in high

Landslide Risk. • Total Budget require for action plan is NRs 2150 Million,

high priorities activities NRs 213 Million should immediately manage.

• More than 50% high vulnerable monuments found in Slesmantak forest (B1 area).

• The major hazard in Slesmantak forest area is Landslide, so to protect cultural heritage attributes and Environment-immediately stabilize the landslide.

• High landslide hazard area’s monuments are in higher Risk having high Vulnerability with the poor state of conservation.

5 Citation …