Sand-duststormisaspecialnaturaldisasterthatfrequentlyoccursindesertsandtheirsurroundingareas.WiththedatapublishedonSurfaceMeteorologicalMonthlyBulletinandSurfaceChartduring1971-1996,thetemporal-spatialdistributionandannualvariationofsand-duststormsareanalyzedonthebasisofthecasestudyofatmosphericprocesses.Furthermore,thetracksandsourceareasofsand-duststormsaredeterminedwiththeaidofGIS.TheresultsshowthatexceptsomepartsofQinghaiProvinceandInnerMongoliaaswellasBeijing,sand-duststormsdecreaseapparentlyintimeandspaceinrecentdecadesinChina.Sand-duststormsoccurmostfrequentlyinspring,especiallyinApril.Accordingtotheirsourceareas,sand-duststormsareclassifiedintotwotypes,i.e.,theinner-sourceandouter-sourcesand-duststorms.Mostoftheouter-sourcesand-duststormsmovealongthenorthandwesttracks.Thenorth-trackouter-sourcesand-duststormsalwaysintrudeintoChinaacrosstheSino-MongolianborderfromHami,acityintheeasternpartofXinjiang,toXilinGol,aleagueinInnerMongolia,whilethewest-trackonesintrudeintoChinafrombothsouthernandnorthernXinjiang.Thesourcelandsofinner-sourcesand-duststormsconcentrateintheTaklimakanDesertanditssurroundingareasinsouthernXinjiang,southernpartoftheJunggarBasininnorthofXinjiang,theHexiCorridorinwesternGansuProvince,thedrydesertsofInnerMongoliaandtheQaidamBasininQinghai.
