Effects of windbreak Forest according to tree species and planting methods based on wind tunnel experiments

Figures & data

Table 1. Main data of experimental facilities.

List	Scale
Form	Closed-circuit wind tunnel
Size of experimental section	5m (W), 2.5m (H), 20m (L)
Wind velocity	0.3–13 m/s, 0.5–31 m/s
Turbulence intensity	Below 1.5%

Figure 1. Structure of small-scale simulation model set up at the 30 cm height from the ground.

Figure 2. Wind tunnel experimental arrangement including locations of trees and measurement points.

Figure 3. Spatial distributions of mean velocity by number of planting lows of Pinus thunbergii.

Figure 4. Spatial distributions of mean velocity by number of planting lows of Quercus acutissima.

Figure 5. Spatial distributions of mean velocity by planting order.

Table 2. Wind velocity and reduction ratio at each sample point for P. thunbergii.

Classification	Distance (cm)	Velocity (m/s)	Reduction ratio (%)
1 row	−10	2.300 ± 0.000^c
	100	0.931 ± 0.355^a	60
	200	1.036 ± 0.272^ab	55
	300	1.084 ± 0.276^ab	53
	400	1.132 ± 0.246^b	51
	500	1.206 ± 0.157^b	48
	600	1.210 ± 0.140^b	47
2 rows	−10	2.300 ± 0.000^b
	100	0.680 ± 0.487^a	70
	200	0.708 ± 0.344^a	69
	300	0.763 ± 0.281^a	67
	400	0.815 ± 0.227^a	65
	500	0.835 ± 0.205^a	64
	600	0.864 ± 0.177^a	62
3 rows	−10	2.300 ± 0.000^b
	100	0.570 ± 0.444^a	75
	200	0.600 ± 0.345^b	74
	300	0.610 ± 0.328^b	73
	400	0.600 ± 0.309^b	74
	500	0.627 ± 0.286^b	73
	600	0.668 ± 0.241^b	71

Table 3. Wind velocity and reduction ratio at each sample point for Q. acutissima.

Classification	Distance (cm)	Velocity (m/s)	Reduction ratio (%)
1 row	−10	2.300 ± 0.000^b
	100	1.134 ± 0.868^a	51
	200	1.104 ± 0.835^a	52
	300	1.092 ± 0.753^a	53
	400	1.115 ± 0.651^a	52
	500	1.143 ± 0.585^a	50
	600	1.165 ± 0.497^a	49
2 rows	−10	2.300 ± 0.000^b
	100	0.722 ± 0.525^a	69
	200	0.680 ± 0.493^a	70
	300	0.673 ± 0.462^a	71
	400	0.680 ± 0.472^a	70
	500	0.727 ± 0.396^a	68
	600	0.788 ± 0.320^a	66
3 rows	−10	2.300 ± 0.000^b
	100	0.611 ± 0.784^a	73
	200	0.615 ± 0.750^a	73
	300	0.582 ± 0.682^a	75
	400	0.572 ± 0.634^a	75
	500	0.784 ± 0.401^a	66
	600	0.950 ± 0.208^a	59

Table 4. Wind velocity and reduction ratio at each sample point for mixed structures of P. thunbergii and Q. acutissima.

Species	Classification	Distance (cm)	Velocity (m/s)	Reduction ratio (%)
P. thunbergii  + Q. acutissima  + P. thunbergii	3 rows	−10	2.300 ± 0.000^b
		100	0.675 ± 0.580^a	71
		200	0.581 ± 0.616^a	75
		300	0.558 ± 0.587^a	76
		400	0.557 ± 0.520^a	76
		500	0.565 ± 0.463^a	75
		600	0.613 ± 0.370^a	73
Q. acutissima  + P. thunbergii  + Q. acutissima	3 rows	−10	2.300 ± 0.000^b
		100	0.717 ± 0.507^a	69
		200	0.707 ± 0.426^a	69
		300	0.697 ± 0.395^a	70
		400	0.675 ± 0.419^a	71
		500	0.717 ± 0.359^a	69
		600	0.768 ± 0.292^a	67