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Table 1 Frequency ratio value calculation by rationing landslide percentage to area percentage

From: Effect of Landslide Factor Combinations on the Prediction Accuracy of Landslide Susceptibility Maps in the Blue Nile Gorge of Central Ethiopia

Factor Class # landslide % landslide # area % area FRV =
   Pixels Pixels a Pixels Pixels b (a/b)
Slope (°) 0 - 5 60 0.388 38089 8.770 0.04
  5 - 10 333 2.151 87417 20.129 0.11
  10 - 15 811 5.239 102933 23.702 0.22
  15 - 20 1430 9.238 77279 17.794 0.52
  20 - 30 4195 27.099 80829 18.612 1.46
  30 - 40 4589 29.645 34095 7.851 3.78
  40 - 67 4062 26.240 13645 3.142 8.35
Aspect Flat 5 0.03 1234 0.284 0.11
  N 424 2.74 29729 6.845 0.40
  NE 1013 6.54 44175 10.172 0.64
  E 2127 13.74 64829 14.928 0.92
  SE 3136 20.26 60584 13.950 1.45
  S 2306 14.90 52443 12.076 1.23
  SW 3144 20.31 73195 16.854 1.21
  W 2366 15.28 67137 15.459 0.99
  NW 959 6.20 40961 9.432 0.66
Plan curvature - 10.7829 - - 1.7917 620 4.005 2810 0.647 6.19
  - 1.7917 - - 0.9103 1704 11.008 20924 4.818 2.28
  - 0.9103 - - 0.1111 4986 32.209 154198 35.506 0.91
  - 0.1111 - 0.1111 1724 11.137 78020 17.965 0.62
  0.1111 - 0.5882 3117 20.136 121053 27.874 0.72
  0.5882 - 1.3815 2315 14.955 49643 11.431 1.31
  1.3815 - 11.7830 1014 6.550 7639 1.759 3.72
Profile curvature - 10.9947 - - 2.3629 767 4.955 3648 0.840 5.90
  - 2.3629 - - 1.0810 1984 12.817 23076 5.314 2.41
  - 1.0810 - - 0.1154 4045 26.130 151550 34.896 0.75
  - 0.1154 - 0.1154 1332 8.605 74725 17.206 0.50
  - 0.1154 - 0.7991 3358 21.693 134940 31.072 0.70
  0.7991 - 1.9956 2737 17.681 40629 9.355 1.89
  1.9956 - 10.8837 1257 8.120 5719 1.317 6.17
Distance from river 0 - 100 5975 38.60 173853 40.032 0.96
(m) 100 - 200 3728 24.08 116838 26.903 0.90
  200 - 300 2305 14.89 63633 14.652 1.02
  300 - 400 1323 8.55 34376 7.916 1.08
  400 - 500 810 5.23 19283 4.440 1.18
  500 - 600 480 3.10 11048 2.544 1.22
  600 - 700 350 2.26 6352 1.463 1.55
  700 - 800 223 1.44 3866 0.890 1.62
  800 - 900 102 0.66 2253 0.519 1.27
  900 - 1000 49 0.32 1351 0.311 1.02
  1000 - 1100 74 0.48 748 0.172 2.78
  1100 - 1200 47 0.30 485 0.112 2.72
  1200 - 1300 14 0.09 150 0.035 2.62
  1300 - 1400 0 0.00 46 0.011 0.00
  1400 - 1500 0 0.00 5 0.001 0.00
Factor Class # landslide % landslide # area % area FRV =
   Pixels Pixelsa Pixels Pixelsb (a/b)
Distance from 0 - 200 11297 72.978 108715 25.033 2.92
Lineament (m) 200 - 400 2017 13.030 84627 19.486 0.67
  400 - 600 930 6.008 61629 14.191 0.42
  600 - 800 487 3.146 47825 11.012 0.29
  800 - 1000 236 1.525 36076 8.307 0.18
  1000 - 1200 169 1.092 26915 6.198 0.18
  1200 - 1400 175 1.130 23374 5.382 0.21
  1400 - 1600 119 0.769 18887 4.349 0.18
  1600 - 1800 42 0.271 12387 2.852 0.10
  1800 - 2000 6 0.039 7334 1.689 0.02
  2000 - 2200 2 0.013 3926 0.904 0.01
  2200 - 2400 0 0.000 1634 0.376 0.00
  2400 - 2600 0 0.000 576 0.133 0.00
  2600 - 2800 0 0.000 281 0.065 0.00
  2800 - 3000 0 0.000 101 0.023 0.00
Land use Agricultural land 7518 48.566 290914 66.987 0.725
  Sparse forest 706 4.561 10747 2.475 1.843
  Rural settlement 55 0.355 16384 3.773 0.094
  Barren land 4085 26.389 12423 2.861 9.225
  Bushes 2813 18.172 88635 20.409 0.890
  River 0 0 10049 2.314 0
  Dense forest 171 1.105 1347 0.310 3.562
  Grass land 39 0.252 1357 0.312 0.806
  Shrubs 93 0.601 999 0.230 2.612
  Urban settlement 0 0 1432 0.330 0
Lithology Quaternary soil 184 1.189 6221 1.432 0.83
  Tertiary lower basalt 7733 49.955 94821 21.834 2.29
  Mesozoic limestone 4011 25.911 129156 29.740 0.87
  Mesozoic gypsum, Mudstone and shale 1170 7.558 140797 32.420 0.23
  Mesozoic lower sandstone 2086 13.475 46758 10.767 1.25
  Paleozoic sandstone 55 0.355 12044 2.773 0.13
  Tertiary upper basalt 241 1.557 4490 1.034 1.51