導賞點 5
小小排水溝可以保護天然山徑?
Can a small drainage protect a nature trail?
下雨時,雨水在山坡會由高向低流,也會沿著山徑流下,帶走天然山徑上的泥土,當水越多或越集中,衝力就越大,泥土的流失也就越多,嚴重時甚至形成凹陷的沖溝。
When it rains, rainwater flows down hillsides and mountain trails, from high to low areas catching loose soil in the process. When the runoff generates enough momentum, soil erosion becomes greater. In severe cases, gullies form immediately.
要緩減水土流失,其中一個方法就是在山徑不同的段落上興建排水溝,分散水的衝力。
One method of reducing soil erosion is to build drainage ditches on different sections of the mountain trail, to disperse and impede the water’s momentum.
以「手作步道」工法造的排水溝變化多樣,會依實際需要選點及設計,其中一個常用做法是以石頭或木頭鞏固排水溝兩側,並於底部鋪上碎石緩阻水流的速度,務求將水分散並緩緩地引向山徑旁邊的植被或土壤排走。
According to the “hand-made trail” manual, there are various methods to make drainage ditches. However, the natural surrounding usually dictates the design and construction process. A typical example is to reinforce the sides of the drain with rocks or logs. Then cover the base with pebbles to slow down rainwater and make sure runoff disperses to the trail’s edges where there is vegetation or soil.
不論用什麼物料建的排水溝,假若它積著垃圾、沙泥、枯葉或雜草,就會「廢了武功」,因此定期清理淤塞的排水溝,把裡面的淤塞物清走,保持排水溝暢通無阻,也是山徑保養的重要一環。
No matter what kind of material is used to build the drainage ditch, if the ditch accumulates with garbage, foliage, sand or soil, it would be rendered useless. Hence regular ditch maintenance which includes clearing out blockages is essential to a mountain’s overall conservation.