Algalbloom,knownasredtide,hasoccurredfrequentlyintheBohaiSeainrecentdecadescausinggreateconomiclossestofisheriesaswellashavingsignificantadverseimpactontheenvironment.A3-DEco-Hydraulicmodelisdevelopedtosimulatetheexplosivepropagationofdiatomanddinoflagellateasafunctionoftheconcentrationofvariousnutrients,riverinflow,tide,temperature,wind,sunshineandrainfall.Themodelisintendedtoanswerthequestionsofhowthe1998BohaiSearedtideoccurred,andtoinvestigatehowenvironmentalfactors,suchastemperature,wind,rainfall,solarradiance,seacurrentsandnutrients,affectthealgalbloomprocess.Theparametersemployedinthemodelarecalibratedwiththedatacollectedintheperiods1982-1983and1992-1993.Resultsfromthemodelindicatethateutrophicationoftheseawateristhebasicconditionforalgalbloom,andthatthe1998redtidewastriggeredbytheabnormalwarmweatherinAugustandSeptember.
