沙尘暴英语简介.ppt

A great disaster film2014 Annual masterpieceHeavy dust here! Bring your own tissue! A dust storm is a meteorological phenomenon common in arid and semi-arid regions. Dust storms arise when a gust front or other strong wind blows loose sand and dirt from a dry surface. Particles are transported by saltation and suspension, a process that moves soil from one place and deposits it in another. Strong Wind~ Loosely Dust Sand Drought or arid conditions, and varied wind causes Over-plowed, over-grazed land Effects Environmental crisis Ecosystem impacts Property damage Injuries, and deaths. Land Desertification Atmospheric Environment Etc. Tremendous! Measures Relieve pressure on pasture by captive breeding(圈养减轻草场压力） Reafforestation（退耕还林） Establish an efficient system of wind prevention and sand fixation.（防风固沙） Conserve water and soil resources.（保持水土） Emphasize on prevention and control of desertification of farmland（防止和控制土地沙漠化） Complete more water conservancy infrastructure construction.(农田水利设施建设） How to survive a dust storm? a. Put a mask over your nose and mouth Method 1 of 3: Surviving a Storm on Foot b.Protect your eyes c.Get to high ground(safe, solid, high point) d. Shield yourself from flying objects e.Wait out the storm Method 2 of 3: Surviving a Storm in a Car Outrun the storm Pull the car over and stop Take cover and stay put Method 3 of 3: Thinking Ahead for Next Time Know where dust and sand storms occur. Heed（留心） dust storm warnings. Be prepared in case of an emergency :A mask designed to filter out small particulates Airtight goggles A water supply A warm blanket Dust Bowl(1930-1936) The period began in 1931 when severe drought covered the mid-western and southern US plains. As the crops died, dust from the over-plowed and over-grazed land, whipped skyward by strong, dry winds, formed great dust storms that became known as black blizzards. In 1932, fourteen dust storms were reported in the US, but in the following year, the numb