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

Geoenvironmental Disasters

Table 2 Representative combinations of factors from each group giving the best landslide susceptibility maps using frequency ratio method

No.	Selected frequency ration maps	Prediction accuracy (%)	# of landslide factors used	# of possible combinations	Min LSI (b)	Max LSI (a)	Difference (a-b)
1	sl+as+pr+pl+li+lu+dl+dr	87.6	8	1	2.54	38.95	36.41
2	sl+as+pr+pl+li+dl+dr	86.2	7	8	2.46	29.73	27.27
3	sl+as+pr+pl+li+lu+dl	87.7*			1.58	36.59	35.01
4	sl+pr+pl+li+lu+dl+dr	87.6			2.37	37.74	35.37
5	sl+as+pr+pl+li+lu+dr				2.36	36.03	33.67
6	sl+as+pr+pl+lu+dl+dr				2.41	36.66	34.25
7	sl+as+pl+li+lu+dl+dr	87.7*			2.04	32.80	30.76
8	sl+as+pr+li+lu+dl+dr	87.7*			1.92	32.76	30.84
9	sl+as+pr+pl+li+lu	86.9	6	28	1.4	33.67	32.27
10	sl+pr+pl+li+dl+dr	86.1			2.29	28.70	26.41
11	sl+as+pr+pl+li+dr	84.9			2.36	26.81	24.45
12	sl+as+pr+li+dl+dr	86.3			1.79	23.90	22.11
13	sl+as+li+lu+dl+dr	87.6			14.42	26.61	25.19
14	sl+pr+pl+li+lu	86.8	5	56	1.29	32.20	30.91
15	sl+as+li+lu+dr	87.0			1.24	23.69	22.45
16	sl+as+li+dl+dr	86.2			1.28	17.79	16.51
17	li+sl+dl+dr	86.1	4	70	1.17	16.34	15.17
18	li+sl+lu+dr	86.8			1.07	22.46	21.39
19	li+sl+pr+lu	87.0			0.67	26.03	25.36
20	sl+as+pl+lu	86.4			0.77	25.21	24.44
21	sl+li+lu+dl	87.7*			0.27	22.78	22.51
22	sl+pl+li+lu	86.9			0.79	26.05	25.56
23	sl+as+li	85.3	3	56	0.28	12.09	11.81
24	sl+dl+li	86.3			0.27	13.57	13.30
25	sl+as+dr	84.7			1.07	13.42	12.35
26	Sl+li+lu	86.9			0.17	19.86	19.69
27	li+sl	85.0	2	28	0.17	10.64	10.47
28	sl+dr	84.3	2	28	0.04	11.13	11.09

Note: sl=slope, as=aspect, pr=profile curvature, pl=plan curvature, li=lithology, lu=land use, dl=distance from lineament, dr=distance from river, LSI=Landslide Susceptibility Index, *=Highest prediction accuracy. a = Max LSI = maximum landslide susceptibility index, b = Min LSI = minimum landslide susceptibility index.