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Table 2 Showing frequency ration and fuzzy membership values for different attributes

From: Landslide hazard zonation mapping using frequency ratio and fuzzy logic approach, a case study of Lachung Valley, Sikkim

Factors & attributes

Landslide grid%

Total area grid%

Frequency ratio

Membership function

Geology

    

Quartzite/Garnet Schist

11.00%

5.40%

2.02

0.181

Permafrost

0.00%

13.50%

0

0

Migmatite/Biotite gneiss

89.00%

81.10%

1.1

0.098

Soil type

    

Loam/sand

0.00%

0.54%

0

0

Rock/loam

9.50%

6.60%

1.44

0.129

Loam/rock

6.82%

20.70%

0.33

0.029

Permafrost

0.00%

4.31%

0

0

Sandy loam

68.18%

35.57%

1.92

0.172

Sandy/clay loam

14.09%

28.89%

0.49

0.044

Sandy/loam rock

1.36%

3.39%

0.40

0.035

Relative relief

    

Very low (0–30 m)

6.25%

16.13%

0.39

0.0349

Low (30–60 m)

18.75%

37.24%

0.50

0.044

Moderate (60–100 m)

50.00%

40.97%

1.22

0.109

High (100–150 m)

18.75%

5.10%

3.68

0.329

Very high (>150 m)

6.25%

0.56%

11.16

1

Slope category

    

0°-5° (Very low)

1.27%

2.03%

0.63

0.056

5°-15° (Low)

2.53%

11.70%

0.22

0.019

15°-25° (moderate)

8.86%

20.61%

0.43

0.038

25°-35° (Moderately high)

22.78%

27%

0.84

0.075

35°-45° (High)

45.57%

31.20%

1.46

0.130

>45° (Very high)

18.99%

7.46%

2.55

0.228

Aspect

    

North

4.83%

0.8%

0.16

0.015

Northwest

10.18%

3%

0.294

0.026

West

14.57%

7%

0.48

0.043

Southwest

14.76%

14%

0.94

0.086

South

10.76%

40%

3.71

0.33

Southeast

16.10%

20%

1.24

0.11

East

16.8%

8.2%

0.48

0.044

Northeast

11.98%

7

0.58

0.05

Flat

0.0017%

0

0

0

Lineament buffer

    

>200 m

56.25%

61.23%

0.92

0.082

0 – 50 m

15.00%

10.39%

1.44

0.129

50 – 100 m

7.50%

10.56%

0.71

0.063

100 m – 150 m

6.25%

9.42%

0.66

0.059

150 m – 200 m

15.00%

8.40%

1.79

0.160

Drainage buffer

    

>200 m

43.75%

78.31%

0.56

0.050

0 – 50 m

18.75%

5.41%

3.46

0.31

50 – 100 m

10.00%

5.84%

1.71

0.153

100 m – 150 m

8.75%

5.12%

1.7

0.152

150 m – 200 m

18.75%

5.30%

3.54

0.317

LULC Type

    

Fallow/Barren Land

53.75%

26.36%

2.04

0.182

Sparse Vegetation

38.25%

30%

1.27

0.113

Dense Vegetation

8%

41.40%

0.19

.017

Settlement

0

0.095%

0

0

Snow cover

0

1.65%

0

0