Metric measurements for optimization of forest road network alternatives in GIS-based programs

Figures & data

Figure 1. (a) Slope layer, (b) soil layer, (c) hydrograph layer of the study area.

Table 1. Weights and ratings assigned to criteria and classes for cost layer modeling by ANP.

Criteria	Importance	Class	Rating	Cost classes
Slope	0.63	0%–20%	1	Low
		20%–50%	2	Moderate
		>50%	3	High
Soil	0.29	1.14	3	High
		2.17	2	Moderate
		4.15	1	Low
Hydro	0.08	0–100 m	4	Very high
		100–200 m	3	High
		200–300 m	2	Moderate
		>300 m	1	Low

Note: The inconsistency index is 0.0904.

Figure 2. Hierarchy used to select the optimal forest road network.

Figure 3. Road network alternatives on cost layer of study area.

Table 2. Physiographical properties of cost classes.

Code	Cost class	Area (%)	Slope (%)	Soil (land code)	Distance from river (m)
1	Low	41.5	0–20	4.15		>300
2	Moderate	46.2	20–50	2.17		100–300
3	High	12.3	>50	1.14		0–100

Table 3. Passage of road network alternatives from different classes of cost layer.

Alternative	Total length (km)	High		Moderate		Low
		km	%	km	%	km	%
RN1	61.273	4.1	6.7	21.7	35.5	35.4	57.8
RN2	61.270	4.0	6.5	20.5	33.5	36.7	60.0
RN3	59.923	4.7	7.8	19.2	32.00	36.1	60.2
RN4	59.650	5.9	9.9	21.1	35.4	32.6	54.7
RN5	61.792	4.1	6.6	23.3	37.7	34.4	55.7
RN6	60.650	4.9	8.1	21.7	35.7	34.1	56.2
RN7	59.970	6.8	11.4	19.5	32.5	33.6	56.1
RN8	61.300	5.4	8.8	20.3	33.1	35.6	58.1
RN9	62.122	5.6	9.0	20.8	33.5	35.7	57.5

Figure 4. Opened areas and overlaps of road network alternatives.

Table 4. Forest openness and overlaps caused by various alternatives of the road network.

	Opened area		Gap		Overlap area
Alternatives	Hectare	%	Hectare	%	Hectare	%
RN1	2384.0	72.13	921.3	27.87	760	22.99
RN2	2023.3	62.21	1282.0	37.79	705	21.33
RN3	2301.0	69.62	1004.3	30.38	730	22.08
RN4	2359.3	71.38	946.0	28.62	760	22.99
RN5	2363.3	71.50	942.0	28.50	745	22.54
RN6	2314.3	70.02	991.0	29.98	626	18.94
RN7	2231.0	67.50	1074.3	32.50	750	22.69
RN8	2393.3	72.41	912.0	27.59	662	20.03
RN9	2287.3	69.20	1018.0	30.80	765	23.14

Figure 5. Forest stock growth capability map.

Figure 6. Road network alternatives according to corrected ton-km.

Table 5. Ton-km values for alternatives.

Alternatives	RN1	RN2	RN3	RN4	RN5	RN6	RN7	RN8	RN9
Y value	117.4	117.9	125.9	132.3	116.8	125.6	126.7	129.6	141.1

Table 6. Weights of criteria and ratings assigned to forest road network (RN) alternatives.

Criteria	RN	Rating	Criteria	RN	Rating	Criteria	RN	Rating	Criteria	RN	Rating
Opened area (0.377)	RN1	8	Ton-km (0.225)	RN1	8	Cost (0.100)	RN1	6	Overlap (0.297)	RN1	6
	RN2	1		RN2	7		RN2	8		RN2	7
	RN3	4		RN3	5		RN3	9		RN3	4
	RN4	6		RN4	2		RN4	1		RN4	5
	RN5	7		RN5	9		RN5	2		RN5	3
	RN6	5		RN6	6		RN6	4		RN6	9
	RN7	2		RN7	4		RN7	3		RN7	2
	RN8	9		RN8	3		RN8	7		RN8	8
	RN9	3		RN9	1		RN9	5		RN9	1

Figure 7. Overall priority of road network alternatives.

Figure 8. Optimum alternative 8.