沙尘暴英语ppt

Pleaselookatthesepictures.Howbeautifultheyare!Butonedaysomethinghappened.Itisasandstorm.Itisveryfrightening.2020/4/215Whatissandstorm?ThereasonforsandstormDamageandpreventionOutlineWhatissandstorm?Sandstormisameteorologicalphenomenoncommonlyfoundinaridandsemi-aridregions.Itisresultedfromconvectioncurrentscreatedbyintensiveheatingoftheground.Thesecurrentscancreatewindupto120km/handAppearasasolidwallofdustasmuchas1,525mhighwhichblowoveralongdistance.2020/4/21TopographicalfactorAtmosphericfactorsExcessivecultivationoffarmland:DeforestationOver-grazingIneffectiveprotectionofconstructivesitesThereasonofsandstormTheaffectofsandstorm1.strongwind2.sandburial3.soildrifting4.airpollutionStrongwindSandburialSoildriftingAirpollutionMeasures1)Protecttheenvironment2)Protectthevegetation3)Developmentofenvironmentalprotectioninfrastructure4)Controllingpopulationquantity,improvingpopulationqualitySometipsWhensandstormcoming:1)Lessgoout,closeyourwindowwell2)Keepindoorhaverelativehumidityandclean3)Ensuresufficientsleep,drinkmorewater,andwashyourhandsfrequently4)Wearamask2020/4/21ThedaybeforeyesterdayYesterdayTodayInordertoweallhaveabeautifulenvironmenttolive,pleaseprotectourenvironment.Becauseit’sourduty.