^Avalanches

^{an avalanch is a mass of snow which comes loose from a steep mountain slope and hurtles down to the valley below.it can be huge and frightening,sweeping away trees and burying houses.Or it can be quite a small slide of snow which may block a path or move a fence.Avalanches are a danger in any mountainous area with bare slopes and heavy snow.Evrey year there are thousands of avalanchs in the ALPS ,butvery few cause death or destruction.}

^{they are a particular danger after a warm spell when the snow begins to thaw.then ,one snow layer can slide over another and crash down the hillside.}

^{avalanchs are worst on bare slopes with no trees to hold back the snow.in some countries ,new forests are being planted to reduce the danger.where  slopes have been cleared for skiing or farming,walls and snow fences are built to break up any avalanches that develop.snow bridges are built over roads and railways to protect them.trained snow patrols keep a special watch and issue forecasts of avalanches in areas popular for winter sports.}

^{At the slightest danger,warnings are broadcast and roads and ski-fields are closed.sometimes,explosives are used to start off a small avalanche to prevent a larger one occurring.}