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本文提出了一种计算树木减小丘陵山区浅层滑坡的影响范围的方法。数字成像的计算机工作法用来研究小山坡的航片,在该照片上可以看到大范围栽植的树木和滑坡断痕。得出了侵蚀面积平均比率及其同树木距离的曲线图,由图推算出了树木影响范围的平均值和受树木保护,没有发生滑坡的地面面积,还估算了在其它地方栽植树木有可能保护山坡不发生滑坡的土地面积。为了证实这一方法,用一在大暴雨期间发生过滑坡的小山坡作了研究。计算得出的侵蚀面积平均比率及其同树木距离的曲线图说明,有滑坡趋势的地方距离树木较远。由于树木不是事先有意地栽植在不大可能出现滑坡的位置,因而,有人推断这种选择是由于树木的某种作用所致。这种作用随着与树木的距离增大而减低,在距树11米(36英尺)处已很微弱。暴雨使研究区20.9%的面积直接失去发展草场的生产潜力,这种破坏作用或者是由滑坡,或者是由泥石流堆积,或者是由二者共同造成的。该研究方法预测,如果没有这些白杨树,受破坏的面积将可能是24.2%,也就是说,研究区3.3%的面积免于直接的生产损失。因此,这些树木使暴雨的破坏损失减少了13.8%。如果树木是以10米的间隔作网状配置,并全部成活,则暴雨的破坏损失最少可降低70%。
This paper presents a method of calculating the effect of trees to reduce the impact of shallow landslides in hilly areas. The computerized method of digital imaging was used to study aerial photos of small slopes where large areas of trees and landslides were visible. The average erosion area ratio and its distance from the tree are plotted and the average of the trees affected by the tree and the area of the ground protected by trees without landslides are estimated from the figure and it is estimated that planting trees elsewhere may be possible Landslide landslide area does not occur. In support of this approach, a small hill where a landslide occurred during heavy rainfall was studied. The calculated average erosion area ratio and its distance from the tree plot show that landslides tend to be further from the trees. Because the trees were not planted in advance in locations where landslides are not likely to occur, one has inferred that the choice was due to some kind of tree effect. This effect decreases with increasing distance from trees and is very weak at 11 m (36 ft) from the tree. Heavy rains caused 20.9% of the area in the study area to directly lose the productive potential of developing pastures, either by landslides or debris flows or by both. The research method predicts that without these poplar trees, the damaged area will likely be 24.2%, which means that 3.3% of the area in the study area is free of direct production losses. As a result, these trees reduced the damage to rainstorms by 13.8%. If the trees are reticulated at 10-meter intervals and survive entirely, damage to the storm can be reduced by at least 70%.