cookieless, no-ads, no threats canyon exploring with Michele Angileri Torrente Tullio
The canyon of Tullio creek lies at the northern border of the hill on which stands Cerreto Sannita village. It begins as relatively narrow and majestic canyon, followed by a wider gorge featuring numerous weirs.
  I remember ...Oh, weirs ... those little dams made with the intention of mitigating the effects of floods. In Italy every creeks have weirs, and many canyons too! They are not nice-looking at they are a problem for canyoneer, because rope can easily get damaged by their sharp edge. Placing bolts on a weir is often difficult, because the concrete crumbles and the stones come away. It is not uncommon to abseil down a weis that's on the verge of collapsing, sometimes eroded from below and therefore with the upper rows of stones coming loose if you place your foot or rope on them... Okay, you might say, flood mitigation is worth a few more problems for those who enjoy going down streams ...
Alas, things are not like this: weirs actually reduce the erosion of the banks by guiding the stream in one direction, reduce the risk of landslides on the slopes, but they
favor the formation of flood waves and increase the destructive power of flash floods.
These are formed, in fact, when water that flows in front goes slower than the one that follows, allowing the latter to reach it.
Thus on the flood front there is an instantaneous flow rate higher than the average of the flood itself: a wave is formed, a wall of water with a very high destructive
potential.
Ugly, uncomfortable, useless in canyons ... but now they are there, and overcoming them constitutes an important part of the descent of Tullio canyon. At least until time and floods have destroyed and swept them away. Copyright © 2002- Michele Angileri. All rights reserved. |
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