NEW METHODS TO PROTECT YEAR-AROUND OPERATION CANALS FROM SNOW

On the canals of year-around operation, severe snowdrifts concentrated on the surface of the ice cover simultaneously affect both thermal and static loads. When ice melts intensively from the lower surface in areas of accumulation of snow masses, and also due to an increase in the static load from snow, longitudinal cracks form on the ice. The snow saturated with water rising up along the cracks, and a gradual sinking of the snow-ice mass occurs. All this leads to decrease in canal capacity, and in some cases to complete blockage of the flow section by snow-ice mass. The purpose of the paper is to find new ways to protect the canal drift and create an impervious canal profile in areas heavily covered in snow. Snow deposition in the canal bed occurs gradually, starting from the edge of canal closest to the snow collection basin side, followed by an increase in the snowdrift shaft in the direction of the wind as snow blizzard arrives to the canal. We propose the method of protecting the canals from snowdrifts by changing the transverse profile of the canal in the sections highly covered by snow. The transverse canal profile is changed by adding a berm to it with a slope coefficient equal to the coefficient the leeward slope and a height equal to the depth of the canal from the leeward slope depending on exact establishing the limit position of the surface of the snowdrifts, at which the canal is blown without snow deposition, regardless of the amount of snow transfer. The proposed methods can be applied in areas of snow transfer on watering and irrigation canals designed for year-around operation.