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Tuesday, April 24, 2012

Landslides .





Landslides - is sliding displacement of masses of rock down the slope arising from the imbalance caused by various reasons (washing away of rocks by water, the weakening of their strength due to weathering or waterlogged sediments and groundwater, systematic shocks and irrational human activities, etc.) Landslides can be on all slopes with a slope of 20 ° or more at any time of year. They differ not only by the rate of displacement of rocks (slow, medium and fast), but also its size. Slow rate of displacement of rocks a few tens of centimeters per year, medium - a few meters per hour or a day of fast-and tens of kilometers per hour or more. By rapid shifts are landslides, streams, when the solid material is mixed with water, and snow and snow-rock avalanches. It should be emphasized that only fast landslides can cause accidents with fatalities.For example, in 1911 in the Pamirs in Russia a strong earthquake (M == 7.4) caused a huge landslide. Slid about 2.5 billion m3 of loose material. Usoy village was swamped with its 54 inhabitants. A landslide blocked the valley of the river. Murghab and formed a landslide lake that flooded village Száraz. The height of this natural dam reached 300 m, maximum depth of the lake, 284 m, length-53 miles.The most effective protection against landslides is their warning. From the complex of preventive measures should be mentioned the collection and diversion of surface water, artificial transformation of the relief (in the zone of possible separation of land reduces the load on the slopes), fixing the slope using piling and construction of retaining walls.Anyone can take the following precautions:leave the danger zone;to inform authorities about the signs of approaching debris flow;in hazardous locations to move with great care;precautions are taken, leaving the first few pebbles in a dangerous cliff to see if there are already signs of impending debris flow;learn about the existence of specific plans to protect people, in order to be ready to participate in their implementation.rural individual moves, the periodic rolls up to 10 meters, so do not get down into the bed of streams after passing through the shaft of debris - may be followed by another shaft.

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