外文翻译 - 基于网络的交互式平台的设计与实现

0外文原文Designandimplementationofaweb-basedplatformtosupportinteractiveAbstractAweb-basedplatformtosupportinteractiveenvironmentalplanninginSouthernCaliforniaiscurrentlybeingdeveloped,aspartoftheGreenVisionsPlanproject.Themaingoalistoprovidetoolsformunicipalitiesandcommunity-basedgroupstoidentifycandidateprojectsitesthatcan:(1)promotemoreequitableparkandopenspaceaccessforlocalresidents;(2)protectandrestorebiodiversity;and(3)protectandenhancewatershedhealth.TheInteractiveParkAnalysisTooloperatesattheparcellevelandprovidesestimatesofpotentialparkuserdemographicsinaseriesofcustomizedreports,asillustratedinthisarticle.TheInteractiveParkAnalysisToolandsupportingmapviewerplatform(liketheothertools)utilizesaclient/serversystemarchitecturethatprovidesuserswithaccesstolarge,detailedgeospatialdatasets.Thesystemarchitectureandimplementationisdescribed,andacasestudyillustratessystemfunctionality.Workisnowunderwaytoexpandtheplatformtoincludeadditionalonlinetoolstofacilitatetheevaluationofbiodiversityandwatershedhealthwithinthestudyarea._2009ElsevierLtd.Allrightsreserved.1.IntroductionTheSouthernCaliforniametropolitanareaisoneofthefastestgrowingurbanareasintheUnitedStates,characterizedbysocialandeconomicpolarization,anddisparitiesinpublicserviceoldercommunities,especiallycommunitiesofcolorandlowincomeneighborhoods,areindesperateneedofnewparksforrecreationalpurposes.SomemunicipalitiesandcommunitybasedorganizationshaveshiftedtheirfocustoGeographicInformationSystem(GIS)analyticaltoolsandgeospatialdatatopromoteequitableaccesstoparksandopenspaceinthepastfewyears.Inaddition,theWorldWideWebhasfacilitatedandnurturedtheuseofGIStechnologiestosupportavarietyofdecisionmakingtasksatthelocalandregionalscales.Duetothegrowingneedsandinterestsofenvironmentalplanners,many1effortshavebeenlaunchedtodevelopandimplementweb-basedenvironmentalplanningtools.Thedevelopmentofonlineenvironmentalplanningtoolshasbeenreportedextensivelyintheliterature.Manyoftheseplanningtoolshavebeendevelopedtosupportdifferentenvironmentalgoalssuchaswatermanagement,soilmanagement,ecosystemandforestmanagement,habitatplanning,andnativevegetationmanagement.Hence,Zhu,McCosker,Dale,andBischof(2001)havedevelopedanonlineinformationsystem,VegMan,tosupportsustainableregionalvegetationmanagementintheCentralHighlandsregionofQueensland.TheCenterforAgricultural,ResourceandEnvironmentalSystemsattheUniversityofMissouriColumbiahascreatedseveralweb-basedspatialdecisionsupportapplicationstoprovideuserswithaccesstohabitatinformationandhydrologicdata,andtohelpwiththemanagementoflivestock,woodlandsandagriculture.Dymond,Regmi,Lohani,andDietz(2004)presentedaspatialdecisionsupportsystemthatintegratedhydrologic,economicandfish-healthmodelsinasingleweb-enabledinterface.Sugumaran,Meyer,andDavis(2004)proposedaweb-basedenvironmentaldecisionsupportsystem(WEDSS)toidentifyandprioritizelocalwatershedenvironmentalsensitivityintheCityofColumbia,andBooneCounty,Missouri.Karnatak,Saran,Bhatia,andRoy(2007)proposedaweb-basedenvironmentalplanningsystemtopromotebiodiversityconservationinIndiathatfeaturedmulti-criteriaspatialdecisionanalysistools.Raoetal.(2007)describedaweb-GISdecisionsupportsystemtoassisttheUSDAinplanningandmanagingConservationReserveProgram(CRP)enrollment.Culshawetal.(2006)proposedanEnvironmentalInformationSystemforPlanners(EISP)toassistlocalauthoritiestodealsystematicallyandefficientlywiththelanduseplanningprocessintheUK.Finally,Sim,Densham,andHaklay(2008)presentedaweb-basedspatialdecisionsupportsystemtohelpplanners,stakeholdersandthepublicidentifyandplanwindenergyprojectsinEngland.Thesesystemsaregenerallyusedbyenvironmentalplannersandmanagers,environmentalanalysts,thedecisionmakerswithinlocalgovernment,thepublicandotherinterestedparties.Alloftheaforementionedonlineenvironmentalplanningtoolsaredesignedbasedontheclient/servertechnology.Withthesetools,dataquerying,geoprocessing,andspatial2decisionanalysisareimplementedattheserverside,whereasuserinteraction,dataandmapdisplay,andreportgenerationaretheendprocessesexecutedattheclientside.Moreover,dependingonthedistributionoftheprocessesbetweenclientandserver,theclientiseitherathinorthickclient.Athinclient(Dymondetal.,2004)isoftenlimitedtodata/resultpresentationwithasimplewebinterface.Ontheotherhand,thickclients(Zhuetal.,2001)supportmorefunctionalitysuchasgroupdecisionmakingandmulti-criteriaevaluation,inadditiontodatapresentation.Varioustechnologiesareusedtodeveloptheclientsandserverswiththeaforementionedsystems.Tobespecific,clientsareimplementedusingwebtechnologiessuchasJavaapplets,JavaScript,HTML,ActiveXcontrols,andbrowserplugins.Ontheotherhand,server-sideprocessesaremainlyimplementedontopofArcIMSserver,ArcGISserver,OGCcompliantwebmapservices,Javaapplications,ActiveServerpages,JavaServertechnology,andotherserver-sidescriptinglanguages.Inthisarticle,wepresentaweb-basedplatformtosupportinteractiveenvironmentalplanninginSouthernCalifornia.TheplatformandInteractiveParkAnalysisTool”thatisshowcasedhereinarekeypartsoftheGreenVisionsPlanfor21stCenturySouthernCalifornia”project,hereafterreferredtoastheGreenVisionsproject(Wolch,Wilson,&Longcore,2009).Oneoftheprimaryaimsofthisongoingprojectistoproduceasuiteofweb-basedGISplanningtoolswhichcanbeusedtohelpguidefutureinvestmentsthatreduceinequitiesinrecreationalopenspace,promotehabitatrestorationandconservation,andimprovenaturalhydrologicfunctioninsouthernCalifornia.Amongallmultipurposeweb-basedenvironmentalplanningsystemsreportedintheliterature,theGreenVisionsProjectPlatform(GVPP)describedinthisarticleisthefirstonlineplanningtoolwhichwill,whenitiscompleted,supporthabitatconservation,watershedhealthandrecreationalopenspaceplanningsimultaneously.TheGVPPservesregionalgeospatialdatasets,includinghydrologicinformation,landcoverandlanduse,wildlifespecies,transportationnetworksandmunicipalboundaries,demographicsandhumanhealthrisks,tonameafew.TheGVPPisfullyaccessibletothegeneralpublicandishostedononeoftheUSCGISResearchLaboratoryservers(GVP,2009).Theplatformisimplementedusingtheclient/serverarchitecturewithathinclient,similartotherelatedwork3discussedearlier.Theimplementedsystemhasafour-tieredconfigurationconsistingofawebclient(Tier1),theIISwebserver(Tier2),theArcIMSMapServer(Tier3),andArc-SDEincombinationwithMSSQLServerasthespatialdatabaseserver(Tier4).Theinnovativepartofoursystemistheabilitytoworkataveryfineresolution.Fewstudieshavedevelopedweb-basedanalyticalsystemsthatoperateatsucharesolution.Allofthewebtoolspresentedundertherelatedwork,forexample,aredesignedforlowresolutionanalysisonuserselectedstudyareasratherthanhighresolutionparcel-basedanalysis.Thesearchitecturesaresuchthattheycannotaffordaveryfineresolutionforsubsequentanalysisanddecision-makingtasks.Thepresentedarticledescribesthedevelopmentofawebbasedplatformthatsupportsuniqueinteractive,on-the-fly”analysesattheparcellevel.UsingtheInteractiveParkAnalysisTool,forexample,ausercanconvertoneormoreparcelsintocandidateparksandvisualizethechangesinpotentialparkuseorpressure.Thistoolthereforeprovidesuserswithaneasywaytoinstantlycalculatedisparitiesinparkaccess,andtheeffectsofaddingoneormorenewparksonsuchdisparities.Theintendedusersaremunicipalities,community-basedorganizationsandenvironmentalplannerswhowanttoidentifypotentialparklocationsthatwillreducethepressureexperiencedbyexistingparksinpark-poorneighborhoodsintheGreenVisionsPlanstudyarea.Theremainderofthearticleisorganizedasfollows.Theoveralldesignandsystemarchitectureoftheweb-basedenvironmentalplanningtoolwillbediscussedinSection2.BysimulatingtheimpactsofanewparkinSection3,thecharacteristicsoftheInteractiveParkAnalysisToolwillbepresentedindetail.Then,theadvantagesandshortcomingsofthedevelopedsystemwillbepresentedfollowedbysomethoughtsforextendingtheplatforminthefinalsection.2.Designandimplementationofweb-baseddynamicanalysissystemTheweb-basedanalysistooldesignsarebasedonaclient/servermodeldividedintofourlevelsoffunctionality.1.ThesefourlevelsconsistofaWebInterface,WebServer,ApplicationServerandSpatialDatabaseServer.TheInteractiveParkAnalysisToolisintegratedwithintheGVPP,whichbeganasabasicmapvieweroriginallycreatedbytheCaliforniaDepartmentofFishandGame(DFG,2007).Basedonpreviousexperience4implementingwebmappingprojects(i.e.Ghaemi,Swift,Goldberg,Swiftetal.,2004;Zimmermann,Bardet,Ku,Hu,&Swift,2003),theinitialDFGmapviewerwascustomizedtodeliverasuiteofmulti-facetedanalyticaltoolsandaccompanyinggeospatialdatasets.Asanonlineenvironmentalplanningtooltoassistenvironmentaladvocates,planners,andmanagersindecisionmaking,theGVPPrequiresthefollowingfeatures.First,thesystemneedstoprovidedataqueryingandextensivenativegeoprocessingcapabilities.Second,itneedstoaffordafastonlinerenderingoflargevectorandrasterdatasetsregardlessofusernetworkbandwidth.Third,itneedstosupportmultipleconcurrentusersandtheresultsfrominteractivetoolsliketheInteractiveParkAnalysisToolshouldbeprovidedinrealtime.Wedescribenexthowtheproposedsystemarchitectureandchosensoftware(ESRIsArcIMS,ArcSDE9.2andMicrosoftsSQLServer2005)satisfytheaforementionedrequirements.2.1.SystemarchitectureTheclientsideisconsideredthefirstlevelwithinthesystem,providingauserinterfacethatacceptsrequests,performsamultitudeofmap-centrictasks,anddynamicallydisplaystheresultsintablesandHTMLformattedpopupreports(Fig.1).TheGVPPprovidesdirectaccesstoapproximately80geospatialvectorandrasterdatasetsgeneratedaspartoftheGreenVisionsproject(Wolchetal.,2009).Theclientfront-endprovidesamaintoolbarthatallowsuserstoperformbasicGISoperationssuchasnavigatingaroundthemapview(zoomin,zoomout,panmap,andzoomtotheextentoftheactivelayer),performingqueriesagainstlayerstoretrieveattributeinformationfordownloadintabularformat(Fig.2),andprintingcustomizedmapviews.Fig.2providesanexampleviewoftheGVPPviewer,andshowstheavailablegeospatialdatalayersintheLayerList”ontheleft-handside,andthebasicmapviewertoolbuttonsinthemaintoolbaracrossthetop.TheLayerListcontrolslayervisibilityandselection,suchthatthedatasetselectedbyauserisreferredtoastheActiveLayer”,thelayeracteduponbythetoolsinthetoolbar.Theclientinterfacealsoprovidesmetadataandlayerpropertiestools,andallowseachusertosaveuniquemapviewsasBookmarks”toberetrievedwhenevertheuservisitstheGVPP.Inaddition,aconvenientDataCatalog”toolhasalsobeenimplementedtofacilitatesearchingforandloadingproject-specificdatalayers5intothemapviewer.DatalayersaregroupedwithintheLayerListbasedondatatypecategories(i.e.GreenVisionsProjectDatalayers,BaseLayers).TheClientsidewasoriginallydevelopedusingJavascript,ActiveServerPages(ASP)andHTML(DFG,2007).Theserversidearchitectureisathree-tieredconfigurationcomprisedoftheTier1WebServer”,Tier2ApplicationServer”,andTier3SpatialDatabaseServer”(Fig.1).MicrosoftInternetInformationServer,IISV.6isutilizedastheWebServer.Whenauserinitiatesarequest,theIISpassesthedatabetweentheclient-sideWebBrowserandtheApplicationServer.TheApplicationServercurrentlyconsistsofthreemainmodules(Fig.1):theMapServer,GVPPapplications,andtheInteractiveParkAnalysisTool.Uponarequestbyauser,oneofthesemodulesislaunchedinordertoexecutetheclientrequestandreturntheresultstotheclientswebbrowser.ThesemodulesarediscussedindetailunderInteractiveParkAnalysisTool”.Whenauserchoosesatoolfromthetoolbarandclicksonthemapview,forexampletogenerateormanipulateit,theWebServerinterpretsthisasauserrequestanddirectstherequesttotheMapServer.TheMapServerexecutesthemappingrequest,launchestheavailablemapserviceintheserviceregistryandsendsapictureofthemapinJPEGformattotheWebServer.ESRIsArcIMSfunctionalitiescomprisethecoreInternetMapServerintheGVPP.ArcIMSServerprovidesbuilt-instandardGIStoolsthatsupporttheservingofGISdata,advancedquerying,focusedGISapplicationdevelopmentviaopenInternetprotocols,andpowerfulmapvisualizationcapabilities.Moreimportantly,ArcIMSServerprovidesfunctionalitybeyond2Dmapvisualization,suchasadvancedgeoprocessingservices,sincethesegeoprocessingserviceswererequiredtoimplementtheinteractiveanalysistoolsliketheInteractiveParkAnalysisToolshowcasedinthisarticle.TheGVPPDatabaseServerhandlestheGreenVisionsPlangeospatialdatasetsorlayers”whichinclude:Baselayerssuchas3-Ddigitalelevationmodels,trails,roads(localstreetsandhighways),naturalandman-madelandmarks(schools,hospitals,airports,etc.),andmunicipalboundaries._Hydrologicdata(updatedstreamnetworks,watersheds,subwatersheds,and6catchments;Sheng&Wilson,2008)._Parcels._Landuse/landcover._Parks(includingforestsandbeaches)._NDVIimages._Census2000demographics._Targetspecieshabitatlayers(includingamphibian,bird,insect,invertebrate,mammal,reptile,andaquaticspecies,targetspe-ciesdensity,andmeasuresofcost-distancethatcapturetheeaseofmovingacrossthelandscapeforasubsetofurban-adaptedtargetspecies).MostofthesegeoreferencedvectorandrasterdatasetsarestoredinMicrosoftSQLServer2005,whilesomelargergridsarestoredinserverdiskspace.ArcSDE9.2isbasicallyagatewaybetweentheApplicationServerandtheDatabaseServer.Itefficientlymanagesspatialdataintheformoftables.ArcSDEprovidessomekeybenefitssuchastheabilitytoservemanyconcurrentusersandnolimittothesizeoftheSQLServerdatabasewhichsupportsthemultipleconcurrentusers,oneofthemainrequirementsofGVPP.Inaddition,thebasicandcustomizedGIStoolsthatworkdirectlywithdatabasetablesratherthanotherformatssuchasshapefiles,greatlyimprovesthesystemperformanceoftheinteractiveelementsliketheInteractiveParkAnalysisToolandmakesitareal-timeservice.2.2.CustomizedGIStoolsTosupportinvestigationofexistingconditionscapturedwiththeGVPPdatalayers,asetofdatareportswasneededwhichwasnotavailableintheinitialsetupoftheDFGmapviewer.Therefore,wehavedevelopedacustomreportingmechanisminASP.Thesereportingapplicationsallowuserstogeneratedynamicpop-updatareportsfromGVPPdatalayers.AtpresentASPreportmodulesarelinkedtotheparks,parkserviceareas,quartermilenetworkbuffersaroundparks,streamnetworks,subwatersheds,andwatersheds.Ausermayselectoneoftheselayers,choosetheIdentifytoolbutton(i”button,Fig.2),thenclickonanyfeatureofinterest.Datafeatures”arerepresentedaspolygons(i.e.parks),lines(i.e.streamsegments)orpoints(i.e.schools).Clickingonafeaturewill7automaticallydisplayalistofoneormorerecords(polygons,linesorpointsandcorrespondingattributes)associatedwiththeselectedlayerinthepanelbeneaththemapview(Fig.2).Forexample,ifauserselectstheParkslayerandthentheIdentifytoolbutton,clickingonaparkofinterestwillgeneratealistofoneormoreparksclosesttothepointorgeographiclocationoftheclick(Fig.2).Apop-updatareportformattedinHTMLcanbegeneratedforanyparkinthelistbyclickingonaParkReport”linkundertheattributeheadingFeatureDetails”.Thegeneratedparkreportincludessomeinformationabouttheparksuchascommunityandculturalfacilities,activeandpassiverecreationfacilities,landscapefeatures,parkcondition,safetyfeatures,andtargetspeciesaswellasaphotogallery.Whilemanyofthesereportssimplyaffordusersanopportunitytoqueryexistingdatalayers,othersreporttheresultsofsomeformofinteractiveanalysisthatenablesuserstoaskwhatif”kindsofquestionsrelatedtoparkprovisionandpressurealongwithhabitatandwatershedconservationandrestoration.TheInteractiveParkAnalysisToolisshowcasedinthenextsectiontoillustratethesetypesofcapabilities.2.3.InteractiveParkAnalysisToolThistoolisanelaborationoftheworkofSister,Wolch,etal(2007),whereinamethodologywasdevelopedforcharacterizingpotentialparkandopenspacecongestionintheGreenVisionsPlanarea.Sister,Wilson,Wolch,Swift,andGhaemi(2007)provideacompellingpictureofthedisparitiesbetweenthelocationofparkresourcesandthelocationsofdisadvantagedpopulations,suchaspeopleofcolorandthepoor,whichessentiallylaidthegroundworkforthisphaseoftheGreenVisionsPlanproject.AparkanalysisgeoprocessingtoolwasdevelopedoutsidethemainshellofthebasicDFG(2007)mapviewerapplicationreproducedinFig.2.ThenewInteractiveParkAnalysisToolassistscommunityorganizationsandmunicipalities(planners,engineers,politicians,etc.)inidentifyingnewparksiteswithintheGreenVisionsPlanstudyareathatwouldreduceexistingdisparities.Usingthistool,userscanselectspecificparcels(e.g.brownfieldsorvacantlands)ascandidatesitesandconvertthemintonewparks.Consequently,theycaninstantlyquantifyhowthenewconfigurationresultingfromtheconversionoftheparcelsto8parkschangespotentialuseorpressure(i.e.demand)forexistingparkintheimmediateneighborhoodofthecandidatesite(s).Therichdemographicdatasetwithinthistoolfacilitatesexplorationofthespatialrelationshipsbetweenparkfacilitiesandsocio-economiccharacteristicsofpopulations(i.e.income,race/ethniccomposition,andagedistribution).TheoveralldesignoftheonlinetoolisbasedontheParkServiceAreaconcept”thatwasdescribedbySister,Wolch,etal.(2007)andcanbesummarizedasfollows.AParkServiceAreaisdefinedasthearea(polygon)surroundingapark(Fig.3).Assumingthateveryoneusesthenearestparkatsomeuniformrate,wecanassigneachpersonintheregiontoaparkbygeneratingThiessenpolygons(similartowhatPearce(2000)didwhendefiningschoolcatchmentareasforcomparisonwithcensusdataintheUK).TheThiessenpolygonofaparkistheareasurroundingtheparksuchthateverypointinsidetheareaisclosesttothecorrespondingpark(BurroughGahegan&Lee,2000).Consideringthatresidentsaremorelikelytoutilizeparksincloserproximityonamoreregularbasis,eachThiessenpolygoncanbeviewedasaParkServiceArea(PSA),witheachparkatthecenterservicingthepopulationwithintheboundsofthepolygon.Sinceapark,initself,isapolygon(andnotapoint),weutilizedtheverticesaroundtheperimetersoftheparksasthepointsfromwhichtheThiessenpolygonswouldbegenerated(Fig.3candd).SincethisstepresultsinmultipleThiessenpolygonsforeachpark(giventhateachparkpolygoniscomposedofmultiplevertices),thepolygonsbelongingtothesameparkarethenaggregated(Fig.3d).ThegeometricresultisalatticeofPSAswitheveryspaceintheregionassignedtotheparkclosesttoit.Thepotentiallevelofparkcongestionforeachparkserviceareaisthenestimatedasthetotalnumberofresidentsperparkacre(orhectare)insideagivenPSA.ThetotalnumberofresidentsperPSAwasestablishedbyintersectingtheLandScan(Bhaduri,Bright,Coleman,Bhaduri,Bright,Coleman,&Urban,2007)populationrasterwiththePSApolygons.TheLandScanpopulationrasterwasgeneratedusingavarietyoflayersdescribingthebuilt”environmentanddasymetricmappingtechniqu