Climate variability and change over southern africa, impacts and challenges--Alec Sithole & Cyril T.F Murewi.

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1、ClimatevariabilityandchangeoversouthernAfrica:impactsandchallenges12AlecSithole*andCyrilT.F.Murewi12DepartmentsofPhysicsandMathematics,MidlandsStateUniversity,P.Bag9055,Gweru,Zimbabwebeenobservedoverthepastfewdecades(Gonzalez,Abstract2002).Inthispaper,theinfluenceofclimateva

2、riabilityandOvermostpartsofsouthernAfrica,theEINinochangeontheenvironmentwasstudiedoversouthernSouthernOscillation(ENSO),whichgreatlycontributesAfricausingground-basedandremotelysenseddata.Atointer-annualrainfallvariability(Rautenbach&Smith,timeseriesanalysisofrainfallandte

3、mperatureanomalies2001),manifestsitselfaseitherEINinoorLaNi~nia~indicatedthattherewasahighrainfallandtemperatureevents.TheE1Ninoevents,whichusuallyresultin~variabilityintheregion.Theinfluenceofglobaltele-delayedandlowrainfall,havebecomemorefrequentconnectionsonrainfallpatter

4、nsoversouthernAfricaoverthepastthreedecades.Withmostclimatemodelshowedthatinsomeareastherewasaspatialvariationinestimatesindicatingrainfalldecreasesofupto20%intheirstrength,increasingfromwesttoeast.MapsofNDVI,manyareasoversouthernAfrica(Barnett,Dessai&from1982to2004,showedt

5、hatchangesinvegetationJones,2003),coupledwithprojectedpopulationin-coverweremoreapparentduringthedryseasonthancrease,futurewaterstressproblemsarehighlyexpectedduringthewetseason.Thestudyalsorevealedthatcli-(Blanc&Perez,2008).Inthelong-term,thesechangesmatevariabilityandchan

6、gearelinkedtodecreasingmaysignificantlyalterlandscapes,wetlandecosystemsthrainfallandhence,decreasingregionalwaterresourcesandotherbio-diversityasobservedoverthe20centuryandbiodiversityandincreasingenvironmentaldegrada-(Biggsetal.,2008).tion.Withtheregionalpopulationexpected

7、increase,thisInthisstudy,climatictrendsandvegetationcoveroverdepletionofresourcesposesthegreatestregionalen-southernAfricaandglobalteleconnectionindicatorswerevironmentalchallengetohumankind.studiedtoassesstheimpactsandchallengesofclimatevariabilityandchangeovertheregion.Ke

8、ywords:challenges,climatechange,environment,impacts,variabilityMaterialsandmethods