基于改进的RCA水质模型对珠江口夏季缺氧及初级生产力的

热带海洋学报JOURNALOFTROPICALOCEANOGRAPHY2010年第29卷第1期：20−31://(,GD908-02-03)作者简介(1981),,,,通信作者：E-mail:[e-mail]海洋物理学RCA张恒,李适宇(,510275):,RCA(rowandcolumnofAesop),RCA,,,RCA,,,,(particulateorganicmatter,POM),,(sedimentoxygendemand,SOD)SOD,,,,,,;,,(particulateorganiccarbon,POC),SOD,,:;;;RCA中图分类号:P731;P735.125文献标识码:A文章编号:1009-5470(2010)01-0020-12AnumericalstudyonhypoxiaandprimaryproductioninthePearlRiverEstuaryinsummerusingthemodifiedRCAwaterqualitymodelZHANGHeng,LIShi-yu(SchoolofEnvironmentalScienceandEngineering,SunYat-senUniversity,Guangzhou510275,China)Abstract:TheRCAwaterqualitymodelwasincorporatedwiththesedimentmoduleandthelightshadingeffectduetothehighturbidityinthePearlRiverEstuary(PRE).ThemodifiedRCAwaterqualitymodelwasthenappliedtothePRE.ResultsshowthatthemodifiedRCAmodelcanreproducethedistributionofnutrients,phytoplanktonanddissolvedoxygen(DO)inthePREsuccessfully,whichmeansthemodifiedmodelcancapturethemainprocessesofwaterqualityinthePRE.Inthewetseason,hugeamountoffreshwaterentersthePREandresultsinariverplume.Particulateorganicmatter(POM)depositsintenselyinspecificareasofwesternandcentralshoaloftheLingdingyangEstuaryandoutsideModaomenasaresultoftheplumes.Furthermore,highdepositionrateofPOMinspecificareasleadstohighsedimentoxygendemand(SOD),whichco-incideswiththeareaswithstrongstratification.HighSODandstrongstratificationleadtohypoxia.Ontheshelfareas,pri-maryproductionincreasesasthesuspendedsedimentconcentrationdecreases,buttheincreasingprimaryproductiondoesnotresultinhypoxiaasthemarineparticulateorganiccarbon(POC)spreadsallovertheshelfandthestratificationisweak.Keywords:PearlRiverEstuary(PRE);sedimentmodule;shadingeffect;RCAwaterqualitymodel:RCA21,,(1),10524m3·s−1,80%,20000m3·s−1[1](NP)(CODBOD5),,;,,,[2−6](particulateorganicmatter,POM),(sedimentoxygendemand,SOD),POM:POM,,,SOD,POM,SOD;,,,POM1139,C1C7;.;.Fig.1SystematicmapofthePearlRiverEstuaryanddistributionoftherivergaugestations,tidalstations,waterqualitysurveystationsandcoastalpollutantsources22Vol.29,No.1/Jan.,2010,,,HydroqualDiToro,RCA(rowandcolumnofAesop)RCA,SODRCA,−(hydrodynamic-eutrophicationmodel3D,HEM3D),Pepin[7],,RCA,,RCA,,SOD,,1RCAHydroqual[7],AesopWASP(waterqualityanalysissimulationpro-gram)[8],:()RCA[9],POMPOM,(sedimentnutrientflux)RCA(1),c(mg·L−1),t(s),E()(m−2·s−1),U(m·s−1),S(mg·L−1·s−1),W(g·s−1),x,y,zRCAWASP,2;3(,,,)(,,,)xyzxyzccccEEEtxxyyzzcccUUUSxyztWxyztxyz⎛⎞∂∂∂∂∂∂∂⎛⎞⎛⎞=++−⎜⎟⎜⎟⎜⎟∂∂∂∂∂∂∂⎝⎠⎝⎠⎝⎠∂∂∂−−±+∂∂∂(1)2RCAFig.2SchematicmapofRCAwaterqualitymodel:RCA23RCA,,,ECOMSED(estuary,coastal,oceanmodelwithsedi-mentmodule)DELFT-3D,RCA,,,(2)s1(),WCGβα=(2)Ws(m·d−1);C1(mg·L−1);G(dynes·cm−2)αβ,αβ8.640.22ECOMSED,(3)1/222M,uvGKzzρ⎡⎤∂∂⎛⎞⎛⎞=+⎢⎥⎜⎟⎜⎟∂∂⎝⎠⎝⎠⎢⎥⎣⎦(3)KM;ρ;uv;z(4)b1bd1bdd1,;0,,PPττττττ=−=≤(4)bτ(dynes·cm−2);dτ(dynes·cm−2);(F)(5):rescr,res11,FFHττ⎛⎞=−⎜⎟⎜⎟⎝⎠(5)(5)Fres(g·m−2·d−1);τ(N);cr,resτ(N);H(m)3RCAFig.3SchematicmapofRCAsedimentfluxmodelPOM,DiToro[9]:e0.0520.1740.031,KNDP=++(6)(6),Ke(1·m−1);N(mg·L−1);DPOM(mg·L−1);Pa(ug·L−1)22.1ECOMSED[10],,,80m(4)2003,123×171(×),400500m34km11sigma,(4)10s,100s4(m)Fig.4Waterdepth(m)inthestudyareaandmodelgrid[1,12],M2S2K1O1,19932002,,3(1),[13],3,24Vol.29,No.1/Jan.,2010,[14]SODA(simpleoceandataassimilation),Gils[15],,NCEP(NationalCenterforEnvironmentalPrediction)199812119991231,199967RCA,120s[16]()[2,15,17]Gils[15]POCPONPOP[18−20][21−22][2,5−6,15]2.2(PearlRiverEstuaryPollutionPro-ject,PREPP)[23]199971727,1,48(),32(13139),7(C1C7),4,13139,NO3−NO2−NH4+PO43−DTNDTPSiO3ChlaDODOCCODSSC1C7,1,312.312,,(5)[5−6,14]3467;SOD8,,20%,20%,,,67,,NO3−,,,,,NH4+ChlaSS(67),,NH4+,,,NH4+;Chla,,,,,;SS,,,;,,,,67,RCA表1潮位、盐度及温度验证的相对平均误差Tab.1Relativeerrorsbetweensimulatedandobservedvaluesoftidalelevation,salinityandtemperature/%12.33()29.24()24.98()8.16:RCA25表2流速和流向在模拟值与观测值之间的相对平均误差Tab.2Relativeerrorsbetweensimulatedandobservedvaluesofvelocityamplitudeanddirection60%40%20%698584527(800)/%87.273.065.8672625570(800)/%84.078.171.2519997(a)(b)(psu)Fig.5Monthlyaveragedsalinity(psu)distributioninthePearlRiverEstuaryinJuly1999表3大面站水质因子在模拟值与观测值之间的相对平均误差Tab.3RelativeerrorsbetweensimulatedandobservedvaluesofwaterqualityvariablesatsurveystationsNO3−NH4+PO43−ChlaDOCDOSS/%30.743.737.855.135.512.351.2表4连续站水质因子在模拟值与观测值之间的相对平均误差Tab.4RelativeerrorsbetweensimulatedandobservedvaluesofwaterqualityvariablesattimeseriesstationsNO3−NH4+PO43−ChlaDOCDOSS/%26.236.434.650.130.216.341.2SOD,RCASOD,35%34,,39RCAChla,,Chla,4ug·L−1,Chla[3],Chla,12ug·L−1,Chla,67ug·L−1,,RCA,600800gC·m−2·d−1,,RCA1011NO3−,NO3−1.2mg·L−10.2mg·L−1NO3−,NO3−NH4+NH4+PO43−,26Vol.29,No.1/Jan.,20106NO3−NH4+PO43−DOCFig.6ValidationresultsofNO3−,NH4+,PO43−andDOCatsurveystationsinsurface,middleandbottomlayers.:RCA277SiChlaDOSSFig.7ValidationresultsofSi,Chla,DOandSSatsurveystationsinsurface,middleandbottomlayers.28Vol.29,No.1/Jan.,20108SODFig.8SODvalidationresultsforsurveyandtimeseriesstationsNH4+PO43−,NH4+0.1mg·L−1NH4+PO43−,NH4+PO43−,NH4+PO43−,,,0.010.04mg·L−1;,NH4+PO43−,,,,,;,,,,,,,,,[24],,,;,,,,(9RCAChla19997Fig.9Compari