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Table 3 Frequency ratio of factors to landslide occurrence

From: Probabilistic frequency ratio (PFR) model for quality improvement of landslide susceptibility mapping from LiDAR-derived DEMs

Factor Class Total number of pixel Landslide occurrence pixel Frequency ratio
  Numbera % Numberb %
Soil Weathered 85,091 0.84 0 0.00 0.00
Medium soil form alluvial 804,145 7.94 0 0.00 0.00
Thin soil over rock 658,226 6.50 15,979 7.80 1.20
Medium soil over the rock 2,185,002 21.57 80 0.04 0.00
Medium soil over colluvial 1,746,851 17.24 60,913 29.72 1.72
Deep soil from alluvial 111,793 10.32 5300 2.59 2.34
Fine alluvial soils 1,045,712 3.45 45,430 22.17 2.15
Thin sandy soils 349,206 31.04 1939 0.95 0.27
Rocks 3,145,180 1.10 75,275 36.73 1.18
Distance from drainage (m) 100 4,424,123 43.67 76,569 37.36 0.86
200 2,464,779 24.33 59,288 28.93 1.19
400 2,222,416 21.94 53,917 26.31 1.20
800 987,245 9.75 15,042 7.34 0.75
>800 40,237 0.40 100 0.05 0.12
Slope
(degree)
0–5 490,045 4.83 3442 1.68 0.35
5–10 669,427 6.60 12,333 6.02 0.91
10–20 2,746,384 27.09 67,408 32.89 1.21
20–30 3,200,304 31.56 67,151 32.77 1.05
30–40 2,530,305 24.96 47,358 23.11 0.94
40–50 453,592 4.47 6937 3.38 0.76
>50 48,743 0.48 310 0.15 0.31
Lithology TRem 27,679 0.27 785 0.36 1.33
PEE 536,418 5.30 2 0.00 0.00
Pn 38,776 0.38 2735 1.27 3.31
Pr 439,706 4.34 5295 2.45 0.56
PV 9875 0.10 39 0.02 0.19
Q 901,467 8.90 10,859 5.02 0.56
Q1 114,961 1.13 96,880 44.81 39.49
TR3JS 1,547,999 15.28 654 0.30 0.02
K1 M2 330,740 3.26 10,652 4.93 1.51
KM2 511,173 5.05 16,768 7.76 1.54
KV22 415,791 4.10 12,040 5.57 1.36
P1Q 277,810 2.74 0 0.00 0.00
Pd 269,380 2.66 42 0.02 0.01
TRdc 360,447 3.56 764 0.35 0.10
CM 804,135 7.94 11,461 5.30 0.67
O1 20,800 0.21 0 0.00 0.00
Factor Class Total number of pixel Landslide occurrence pixel Class
Numbera % Numberb %
Lithology E1 197,786 1.95 0 0.00 0.00
Eb 87,995 0.87 1 0.00 0.00
PEK 1,483,288 14.64 6760 3.13 0.21
J1 83,479 0.82 147 0.07 0.08
K1 309,512 3.06 1364 0.63 0.21
K11 20,444 0.20 3925 1.82 9.00
K12 697,915 6.89 10,374 4.80 0.70
kv21 614,502 6.07 13,330 6.17 1.02
river 25,575 0.25 0 0.00 0.00
lake 2424 0.02 64 0.03 1.24
Land use Agriculture land 1,467,497 14.49 78,969 38.53 2.66
Settlement 407,629 4.02 9869 4.82 1.20
Open Vegetation 2,914,371 28.77 49,777 24.29 0.84
Lake 2101 0.02 163 0.08 3.84
Grass land 1,395,207 13.77 36,045 17.59 1.28
Dense vegetation 3,385,573 33.42 30,078 14.68 0.44
Bad land 558,122 5.51 38 0.02 0.00
Distance from road (m) 50 226,534 2.23 15,779 7.70 3.45
100 223,772 2.21 14,477 7.06 3.20
200 428,101 4.22 20,930 10.21 2.42
400 784,725 7.74 30,603 14.93 1.93
800 1,344,647 13.26 31,178 15.21 1.15
>800 7,131,021 70.33 91,972 44.88 0.64
Geomorphology Debris land 255,864 2.53 15,629 7.23 2.86
Deep valley 670,098 6.61 45,181 20.90 3.16
Limestone Relief 1,373,183 13.56 3040 1.41 0.10
Moderate Relief 2,238,436 22.10 58,355 26.99 1.22
Alluvial Fan 263,711 2.60 0 0.00 0.00
Alluvial Plain 385,201 3.80 0 0.00 0.00
Alluvial Terrace 311,277 3.07 10,000 4.63 1.51
Volcano Relief 4,632,287 45.73 72,711 33.64 0.74
  1. aTotal number of pixels in the study area: 10,138,800 pixel (Without no data)
  2. bTotal number of landslide occurrence pixel: 204,939 pixel (Estimation group)