An approach for the reduction of the sediment volume transported by debris flow from the high-sloping reach of a debris-flow channel

Usual works for the reduction of the sediment volume transported by debris flows are the retention basins. Retention basins are usually built on the intermediate and low-sloping reaches of the debris-flow channels or at their end, where the terrain slope is usually not high. When the space required for trapping all the sediment volume is not available or the upper part of the basin must be protected deposition areas can be used. The deposition area is a retention basin without the downstream berm, to be placed in the high-sloping reach of a debris-flow channel. Therefore, it is proposed an approach for the progressive reduction of the sediment volume transported by debris flow: an in-series combination of deposition areas in the high-sloping reaches of the channel, and retention basins in the intermediate low-sloping reaches of the flow path.

An application of such approach is shown for the design of the control works on Ru Secco Creek at the purpose of defending the resort area and the village of San Vito di Cadore (Northeast Italian Alps).