Avalanche protection - the drift construction

An avalanche barrier is a structure designed to prevent the formation and sliding of avalanches and to protect infrastructure such as settlements, traffic routes and sports areas. As a result of human encroachment into alpine areas where the mountain forest or protective forest is insufficient or non-existent, artificial means must be used to stabilize the snowpack and prevent the sliding of snow masses. There are four main types of avalanche barriers: The drifting shoring, the supporting shoring, the braking shoring and the deflecting shoring. Today we will introduce the snowdrift shoring:

The drifting shoring prevents unfavorable deposition of snow by the wind at possible breakout points. In this way, the danger of avalanche formation can be limited. Here, even small-scale structures have a great influence. Such structures are snow fences. They are erected at wind-exposed locations in order to reduce the wind speed there. Even at half the wind speed, only one-eighth of the original amount of snow is transported. The snow is deposited on the downwind side before it is blown into an avalanche starting area, where it creates a dangerous drifting snow deposit. Snow fences are therefore used primarily on flat ridges above an avalanche slope. The efficiency of snow fences depends on their height and the degree of filling. Typical fence heights are 3 to 6 meters. The degree of filling indicates the ratio of the closed to the total fence area. The best effect is achieved when snow fences are positioned perpendicular to the wind direction and have a fill ratio of 0.5 to 0.7. Retaining structures are often used in combination with scour boards and wind nozzles. Scour boards are usually positioned on ridges. They do not retain snow, but cause more favorable deposition by creating wind turbulence. To achieve an ideal effect with drifting structures, years of observation of wind direction and snow distribution are necessary.