Beachnourishmentprojects,practices,andobjectives - PDF document

Beachnourishmentprojects,practices,andobjectives—aEuropeanoverviewH.Hanson,A.Brampton,M.Capobianco,H.H.Dette,L.HammC.Laustrup,A.Lechuga *Correspondingauthor.Fax:+46-46-222-4435.E-mailaddress:Hans.Hanson@tvrl.lth.se(H.Hanson).www.elsevier.com/locate/coastalengCoastalEngineering47(2002)81–111 particularorder,describingthepresentsituation.Foreachcountry,thegeneralsituationisbrieflydis-cussedtogetherwithanoveralldescriptionofprojecttypes,objectives,design,andevaluation.Intheconcludingsectionofthispaper,acomparisonbet-weenthedifferentcountriesispresented,wherecommonfeaturesaswellasdifferencesaredis-cussed.Thisincludesthemoredetaileddesignas-pects–methods,considerations,constraints,filltypes,methodologies,andequipment.ThepaperalsogivesabriefdescriptionofthebeachnourishmentsituationinothercountriesoftheEuropeanUnion.2.BeachfillsinGermany(DE)Germanyhas1900kmofcoastline.Ofthis,justunderonethirdconsistsofsandybeaches,whichinmanycasesareexposedtocoastalerosion.Upuntil1950,shoreprotectioninGermanywasmainlyachievedthroughhardstructures.Thefirstfillinmoderntimeswasperformedin1951ontheIslandofNorderney.Sincethen,therehasbeenagradualchangefromhardtosoftprotectionmeasuresinsandycoastalzones.Afterthefirstfill,morethan130fillshavebeenperformedin60differentsites(Fig.1)addinguptoatotalfillvolumeofabout50Mm.AppendixAliststhebeachlengthsandnourishmentvolumesforprojectswherethesenum-berscouldbeestablished.2.1.ProjecttypesandobjectivesThemainlandoftheGermanNorthSeacoastisprotectedbyseadykes.BeachfillsarecarriedoutinsandybeacheswhicharepredominantontheEast-frisianIslands(FederalStateofLowerSaxony)andontheNorthfrisianIslands(Schleswig-Holstein)intheNorthSeaandalongthecoastlineoftheBalticSea(Schleswig-HolsteinandMecklenburg-Vorpom-mern).Theprotectionoftheislandsisofhighprioritybecausetheirpresenceisconsideredasalarge-scalenaturalbarrierthatprotectsthemainland.NotonlybecauseofthedifferentcoastalconditionsbutalsobecausethefederalstatesinGermanyhavedifferentprotectionpolicies,theprojectobjectivesmayvarydependingonlocation:1.Softprotectionofseawallsandrevetmentsagainstlocalscourthroughtoenourishments,mainlyontheIslandsofNorderney,Sylt,Fo¨hr,andAmrum.Theeffectivetotallengthis10kmandsofar,11.5Mmofsandhavebeenfilledfrom1962to2.Strengtheningofdunesandbeachesinordertokeepshorelinesattheir1992positionsintroduced Fig.1.DocumentedbeachnourishmentsitesinGermany.H.Hansonetal./CoastalEngineering47(2002)81–111 asalegalinstrumentintheislandofSyltalong30kmofdunesandcliffaddingupto22Mm1983to1996,andmaintainingacritical,minimumbeachprofileinfrontoftheduneatLangeoogalong3kmwithatotalvolumeof2.9Mm1971to1994(Dette,1998)3.Seawardandlandwardextensionofnaturaldunesashighwaterandfloodingprotectioninordertoprovide,atalltimes,aminimumnaturaldunewidthof40–45malongtheBalticcoastlinewithaneffectivelengthof144kmin36sites.4.Erosionmitigation,i.e.raisingandwideningofthebeachandthenearshoreunderwaterbermprofilealongtheBalticcoastlinewithatotaleffectivelengthof50kmin20sites.Totalvolumeaddsupto7.8Mmofsandfrom1968to1994.5.Compensationoflee-erosioncausedbycoastalstructuresinSylt,withaneffectivelengthof2.5km.Totalfillvolumesofaris2Mmfrom1995to1997.Also,atWarnemunde,BalticSea,withaneffectivelengthof2.2kminninerefills,atotalvolumeof1.0Mmwasfilledfrom1972toThesefivetypesofprojectsarecarriedoutintheframeworkoflegalcoastalprotectionbycoastalauthorities.Inaddition,localcommunitiestakeinitiativestoimprovetheirbeachesforrecreationalpurposes.Type2abovewasaresultofachangingpolicyovertimefromnoprotectionmeasurestomanmadeinterferenceandthefavouringofbeachnourishmentinsteadofcontinuousmaintenanceofhardstructures(seawallsandrevetments).ThispolicywasintroducedintothelegalframeworkforSyltintheearly1990s.2.2.Execution,designandevaluationThedesignmethodsinordertomeetthevariousobjectivescanallbeclassifiedintothecategoryofgenerictemplates.Refineddesignstagemethodsareattheverybeginningofbeingconsideredasdesigntools.Maximumstormsurgelevels(i.e.noover-toppingofdunesandnobreaching)andlongshoretransportratesarethemajordesignparameterstakenintoconsideration.Waverun-upanddepthofclosurearenotconsidered.Nootherdirectdesignconstraintsaretakenintoaccount.Environ-mentalconcernsareonlyraisedinthelicensingofoffshoreborrowareas.Recreationaldisruptionsinhighseason(July–September)areavoidedbytim-ingtheexecutioninthemonthsofApriltillJune.Aeoliantransportinfrontofresortsisminimisedbyinstallingfencesorbushes.Thereisageneralambitiontouseatleastthesamegrainsizeasthenativeone,butpreferablyacoarserone.Structuralsupportsincombinationwithafill,forexampleageotextilebarrierinthefillbodytoreduceerosionduringmajorstormsurgesorunderwatersillstoreducewaveenergyimpactonthebeachfill,havebeeninvestigated.However,thesearestillfarfrombeingacceptedassupportingtools,partlyduetothementalreasonsoftheauthor-itieswhoarguethatifstandardfillpracticeiswellproved,whychange.FortheprotectionoftheWesterlandseawallinSylt,threeunusualdesigntypesweredeveloped(DetteandGa¨rtner,1987)including(1)asuccessfulspit-typefillwhichextendedseawardsmorethan350mfromtheseawall,(2)alesssuccessful,linear,1-kmlongfillto3maboveMHW,and(3)thecombinationofbothpreviousdesignscalleda‘‘girland-type’’fillwithsatisfyingresults.Innearlyallfillsites,initialprojectshavebeencarriedoutwithanexpectedrenourishmentperiodof5–7years.Profileandbermnourishmentsarethetypicalfilltypes.Offshoremoundshavesofarnotbeencarriedout.Bermnourishmentfillprofilesincorporateacertainprecautionaryvolume.Withrespecttoaninitialoverfillration,sofar,noadequatedesigntoolshavebeeninitiatedbytheauthorities,probablyduetothephilosophythateachamountofsandisabenefitforthefillsiteandfortheneigh-bouringareas.Hopperdredgerswithtrailingsuctionandload-ingcapacitiesofupto8000marethetraditionalequipmentforoperationinnearshoreborrowareas.Stationarydredgerswithdeepsuctionandsinkerlinesattachedtothebeacharemostlyusedinshelteredareas.Afterusingtrailingsuctionduringthefirstyears(1985–1988),excavationofborrowmaterialindeeperwater(e.g.morethan15m,likeoffSylt)laterturnedouttobemoreeffectivethroughdeepsuctiondredgerwhichwereanchoredH.Hansonetal./CoastalEngineering47(2002)81–111 duringthetimeofloading.Problemsanddisadvan-tagesduetoroughsea(wavesbetween1and2m)atfirst,expectedfromthe‘‘stationary’’deepsuctiondredging,werenotexperiencedwiththeanchoreddredgers.Ingeneral,coastalprotectioninGermanyisdonewithinawell-developed,long-termstrategyforactionsalongthecoast.Formostprojects,theres-ponsibleauthoritiesareimplementingfollow-uppro-grammes.However,seriousoverallperformanceevaluationprogrammesarestillnotusedtoanyextent,andonlyusedinspecialcases.Almostallofthewell-documentedprojectsarelocatedontheislandofSylt.2.3.LegalandfinancialaspectsGermancoastalprotectionisregulatedbytheconstitutionallawintermsoftheConflictingLegis-lationAct.Thenationalgovernmentmayapplythisright,ifamatterisnotregulatedeffectivelybyfederallaworifthelegislationofonestateinterfereswiththelegislationofotherstatesorthatoftheentirenation.Thefivecoastalfederalstateshaveformulatedspecialregulationsforcoastalprotectionintheirfederallegislation.Althoughtheseregula-tionsdifferincertainaspects,thenationalgovern-menthasnotyetmadeanyuseoftheConflictingLegislationAct.Thenationalgovernment,beingawareofitsover-allresponsibility,financiallysupportsthecoastalprotectionworksofthecoastalfederalstates.Thissupportissubsidiary,i.e.nationalfundsareonlygrantedifmatchedbyfundsfromtheconcernedfederalstates.In1969,Article91awasamendedtotheCon-stitutionalLawof1949.Inthisarticle,thecooper-ationbetweenthenationalgovernmentandthefederalstateswaslegallyestablishedbymeansof‘‘jointtasks’’.Suchtaskshavetobeclassifiedasbeingofnationalimportanceandasbeingnecessaryforimprovingthestandardofliving.Coastalprotec-tionhasbeenidentifiedassuchjointtaskand,thus,wasincludedinArticle91a.Thenationalfinancialshareinthesetaskswasfixedat70%.Theprotectionofsandycoastlinesagainststormsurgesanderosionbymeansofrepeatedbeachfillsandnourishmentsishandledindividuallybythecoastalfederalstatesintermsofthe‘‘generalpro-tectionguidelines’’orsitespecificmasterplans.Since1950,morethan95%ofallnourishmentsitesinGermanyhavebenefitedfromthoseregulations.Therest,e.g.smallfillprojectsmostlyforrecrea-tionalpurposes,arefinancedbylocalauthoritiesonthebasisoftheirowninterest.Withinthislegalscheme,theeconomyofcoastalprotectionprojectsisnotconsidered.Sofar,economicjustificationoroptimisation(designvs.cost)ofsuchprojectsisnotcompulsory,partlybecausethereisyetalegalorpublicpressuretodoso.Afternearly50yearsofexperience,themethodofactivecoastalprotectionbymeansofrepeatedfillsisastandardtoolwitheverincreasingimpor-tance.However,thenextsteponhowtominimisetheregularrefillsandbythesemeansreducetheexpenditurestillliesaheadandispresentlyunderdiscussion.3.BeachfillsinItaly(IT)Italyhas7500kmofwhichjustunderhalfconsistsoflowlyingalluvialbeds,particularlyexposedtocoastalerosion.Anideaontheimpor-tancethatItalyattachestoitsproblemsincoastlineengineeringcomesfromthenorthernAdriaticbeaches,holidaydestinationofmorethan90milliontouristsfromItalyandnorthernEurope.Theannualrevenuefromatypicalsquaremetreofbeachfromtourist-relatedactivitiesapproachesUS$3200,whichisroughlyequivalenttothecurrentmarketvalueof1ofapartment.InItaly,modernbeachfillshavebeenpractisedsince1969.Duringthisperiod,about50fillshavebeenperformedin36sites(Zaggia,1998)uptoatotalfillvolumeofabout15Mm(Fig.2)Alargemajorityofthesefillsaresmall-sizeinter-ventionsaround100–150.Theexceptionsare(1)fourlargeinterventionsatCavallino,abarrierbeachintheLagoonofVenice,andPelles-trina,abarrierbeachinfrontofVenice(7.6Mm(2)RavennainthePoriverdelta(1.4Mm),(3)OstiaclosetoRome(1.4Mm),and(4)BergeggiontheItalianRiviera(2Mm).AppendixBliststhebeachlengthsandnourishmentvolumesforprojectswherethesenumberscouldbeestablished.H.Hansonetal./CoastalEngineering47(2002)81–111 3.1.ProjecttypesandobjectivesAlmostallprojectscompriseofacombinationofsandnourishmentandhardstructures(Benassaietal.,1997).Thesedifferentprojectsmaybeattrib-utedtooneofthefollowinggeneralobjectives:(1)erosionmitigationatlocalscale,(2)enhancedrecreationataverysmallscale,and(3)insouthernItaly,thereisoftenaneedtosafeguardthecoastalrailway.Theseinterventionsmay,almostgenerally,beregardedasremedial(counteractive)ratherthanpreventive(proactive)measures,i.e.emergency-typeactionsaretakenasproblemsareidentifiedalongthecoastwithoutanylong-termplanningoroverallstrategy.3.2.Execution,designandevaluationMostprojectsarebasedonagenericdesignwithacombinationofhardandsoftstructures.Mostminorprojectsaredesignedbysimplescopingmethodsutilisingcrudeevaluationsofshorelineretreatratetogetherwithanevaluationoftheequilibriumslope.Inlargerprojects,thesomewhatmorerefineddesignmethodsareused,whereacrudeevaluationofthelongshoresedimenttrans-portrateiscombinedwithdetailedcomputationsofthevolumebudget.Inaddition,theDutchmanualisconsultedindetermininglong-termtrends,renourishmentintervals,etc.Physicalmodeltestsarequitecommonforlargerprojects.However,numericalmodelsarenotused,withtheexceptionofthePellestrinaandCavallinoprojectswhere,tosomeextent,suchmodelswereused.Theseprojectswere,however,undertakenintheparticularframeworkoftheSpecialLawfortheSafeguardofVenice.Ingeneral,monitoringisonlylimitedornotdoneatall.Also,thereisnoestablishedmethodologyformaintenanceschemes,andnoactualperformanceevaluationismadefortheprojects. Fig.2.DocumentedbeachnourishmentsitesinItaly.H.Hansonetal./CoastalEngineering47(2002)81–111 3.3.LegalandfinancialaspectsInItaly,coastalwatersandbeachesareState-owned.ThismeansthatinitialcostshavegenerallybeenattributedtotheState,whiletheregionalgovern-mentsareresponsibleforthemaintenanceandasso-ciatedcosts,atleastformally.Exceptionstotheattributionofthemaintenancecostsaretherules,typicallybasedontheoccurrenceofextremeeventsthatrequirethesupportofemergencymeasures(withfundscomingfromtheState).Revenues,however,gotothemunicipalities.Inthepast,therewerehardlyanycost–benefitanalysesofprojects.Whatismostevidentis,thus,thediscrepancybetweenwhoispayingandwhoisreceivingthebenefits.Thesitua-tionisanticipatedtochangeinthefuture.TheLawof1907distinguishedbetweentwotypesofcoastaldefences:thosetoprotectbuilt-upareasandthosetohaltbeacherosion.Concerningtheformer,thelocalplanningauthorityisinchargeandcanobtainfinancialsupportfromtheMinistryofPublicWorks,onceitsoperativesectionshaveconsideredtheworkstobetechnicallyfeasible.Inthesecondcase,boththemunicipalityandtheportauthoritycanapplyforfinancialsupportfromtheMinistryofPublicWorksinordertobuildupthedefences.TheDecreeLawof1985restricteddevelopmentto300minlandfromthehighwatermark.Theregionswererequestedtoissueterritorialandlandscapeplansaimedatregulatingtheusesoftheseareasandensuringtheirsustainableexploitation.Stabilisationofdunesinordertoprotectthehinterlandisnowbeingconsidered.Newlegislativedevelopmentsareexpectedbytheapplicationoftheso-called‘‘coastalplan’’,currentlyunderpreparationbytheMinistryoftheEnvironment.Othernewlegislativedevelopmentsthatcouldeven-tuallymoveinthedirectionof‘‘coastalzonema-nagement’’arealsoexpectedfollowingthepossibleadoptionofthestrategicenvironmentalassessmentforthecoastalzoneandthetransferofcompetencefromtheStatetotheregions(Lawof1997).4.BeachfillsintheNetherlands(NL)IntheNetherlands,modernbeachfillshavebeenpractisedsince1970.Duringthisperiod,about200fillsandrefillshavebeenperformedinabout35sitesaddinguptoatotalfillvolumeofabout110Mm(Fig.3).Since1991,theaveragefillvolumeamountstoabout6Mmperyear.TheNetherlandshasstruggledformanycenturiestosafeguarditsterritoryfromflooding.Thewesternpartofthecountryisbelowmeansealevel.LargeportionsoftheDutchcoastarerecedingsincelong.Historically,thisrecessionhasbeenstoppedatsomeplaceswithdykes,whereasatothervariousplaces,nostrictmeasureshavebeentaken,ortherecessionhasmerelybeensloweddownwithgroinsandfences.Thus,ingeneral,thepolicywaspreviouslyoneofselectiveretreat.Thedisastrousfloodingin1953oflargepartsofthesouthwesternpartoftheNetherlandsledtoachangeinthispolicyandtothelegislationconcerningminimalsafetystandardsforthecoastagainstflooding.Afurtherstepinthisdirectionwastakenin1990whenthepolicyofdynamicpreservationwasadopted(Anonymous,1990).Thiswasbasedonthepresump-tionthatitistechnicallyandeconomicallypossibletocompensatenaturalerosionofsandycoastsbynour-ishment.Priortothispolicy,nourishmentswerecarriedouttoreinforcedunesagainstbreachingaspartofthesafetylegislation.Asanexample,Appen-dixCliststhebeachlengthsandnourishmentvolumesforvariousprojectsthathavebeensubjecttoan Fig.3.DocumentedbeachnourishmentsitesintheNetherlands.H.Hansonetal./CoastalEngineering47(2002)81–111 evaluationofnourishmentperformance4.1.ProjecttypesandobjectivesAfteradoptingthedynamicpreservationpolicy,theoverallobjectivehasbeentopreservethe1990coastlinelocationthroughnourishmentsonana-tionalscale.Thus,policyimpliesthatthefuturecoastlineshouldnowherebelandwardofthe1990position.Whenrequired,sandisnourishedtowarrantthelatter.Throughthisprocedure,thelegalsafetystandardsareexpectedtobemetautomati-callyinmostplaces.4.2.Execution,designandevaluationTheresponsibilityforcoastalprotectionintheNetherlandsisdividedbetweennational(Rijkswa-terstaatwhichalsohavelocaloffices)andregionalauthorities,withtheso-calledwaterboards.AlocalRijkswaterstaatbodydesignsthenourishmentandproducesablueprintcoveringallaspectstobetakenintoaccountbyacontractor,suchasplaceofsandmining,shapeofthenourishedprofile,i.e.howmuchsandhastobeplacedineachprofile,inwhichtimeframetheworkshouldbeperformed,etc.Thus,thedesignisverystrictwithlittlevariationfromsitetosite(CUR,1987).Theprin-cipaldesignparametersare(1)nourishmentvol-ume,dependingontherateofautonomouserosionandtherequestedlifetimeand(2)effectivenessfactorofnourishedsand.Thelatterisdefinedastheratiooftheautonomouserosionratebeforetotheactualerosionafterimplementationofthenourishment.Thecoastlineisdefinedbyameasuredsandvolume(derivedfromannualcross-shoreprofiles,seebelow)ratherthanfromanobservedhorizontallinesuchastheMLW.Beachnourishmentsaredesignedtocompensateforthenaturallossofsandinacoastalstretchforadefinedperiodoftimetocome.Theamountofsandtobefilledis,thus,calculatedbymultiplyingthedesignlifetimewiththeannuallossderivedfromtheregressionovertheprevious10years.Theamountisthencorrected(byadding10–20%)forthesite-dependenteffec-tivenessfactortoaccountforthepossibleslightlyincreasederosionrateafterthenourishment,com-paredtotheautonomousone.Insomespecialplaces,anotherposition,moreseawardthantheactualone,hasbeendeliberatelydefinedasthe1990criterion,inordertoensurethatthesafetyofthecoastwillbeautomaticallywarrantedaslongasthecoastlinemeetsthe1990criterion.Inaddition,safetyagainstfloodingischeckedeveryyear,onthebasisofmeasuredprofiles.Theevaluationofnourishmentsisbasedonannualsurveys,performedalongtheentireDutchcoastsince1965,withcross-shoreprofiles200–250mapart.Duringoperations,thetreatedsectionsofthenourishmentsitearesurveyedbeforeandsoonaftertheirtreatment,inordertoachievepropernourishmentvolumevalues.Selectednourishmentshavebeenevaluatedbasedonthefollowingcriteria:effectivenessfactor=ratiooferosionratebeforeandafternourishment;preser-vationfactor=ratioofactuallifetimeanddesignlifetime;recreationfactor=ratioofbeachwidthafterandbeforenourishment;naturalvaluesfactor=ratioofactualanddesignlifetimeofdunefootstabilisa-tion;floodprotectionfactor=ratioofactualanddesignlifetimeinmaintainingtheduneprofile.4.3.LegalandfinancialaspectsThenewSeaDefenceLawof1996regulatestheresponsibilityformaintainingthesafetyagainstfloodingandthedivisionoftasksbetweengovern-mentandregionalauthorities.Maintenanceoftheprimaryseadefencesishandledataregionallevel,throughthewaterboardswhoaresupervisedbytheprovinces.Becauseofthenationalinterestinsafety,theMinisterofTransport,PublicWorks,andWaterManagementhastheoverallsupervision.Fordunesystems,alargepartoftheprofileisconsideredtomakeuptheprimarydefence,fromtheshorefacetothelandwardsideofthefirstdune.Thelocalwaterboardsareinfirstinstanceresponsiblefortheduneswhilethegovernmenthastomaintainthecoastline.Thisapproachobviouslyrequiresclosecollaborationbetweenthetwolevels,whichtakesplaceonaprovinciallevelintheso-calledprovin-cialconsultativebodies(POKs),eachconsistingofrepresentativesfromtheprovincialgovernment,thelocalwaterboard(s),andtheRijkswaterstaat.TheH.Hansonetal./CoastalEngineering47(2002)81–111 provincialauthoritieschairthePOKstoensurethatcoastalmanagementisinlinewiththeregionalplanningpolicy.AccordingtotheSeaDefenceLaw,theduneprofilesaremeasuredatleastonceayearandwheneverthestandardsarenotmet,measureswillbetakenwithhighpriority.ThelocalRijkswaterstaat’sauthorityisalsores-ponsiblefornumerouspermitsneeded.Theyhavetobegrantedbylocalmunicipalities,waterboards,etc.Theyconcern,interalia,permissiontoworkintheareas,suchasinstallingpipelinesandpumpingstations.Theremayberegionaldifferences.Forexample,inoneprovince,thebeachhasremainedunderthejurisdictionofRijkswaterstaat,forthespecificreasonofcontrollingthepermitstoworkthere,whileinanother,ithasbecomepartofthewaterboard’sresponsibility.Fortunately,withthepresentdayexperience,obtainingthesepermitsisaroutineoperation.Inthepolicyofdynamicpreservation,theMinisterofTransport,PublicWorks,andWaterManagementhastoinformtheparliamentevery5yearsontheresultsofthispolicy.Afirst(interim)reportwasprovidedin1993;afirstfullreportin1995,whilethenextonewasduein2000.Thepolicywillbecontinuedforthetimebeing.Withthemaintenanceschemebuiltintothelegalstructure,littleeconomicjustificationisnecessaryforindividualprojects.5.BeachfillsinFrance(FR)ThetotallengthofcoastlineinmainlandFranceisestimatedatabout5500kmincludingsome1960kmofsandybeaches.Coastaldefenceworksarequitesignificantbutnourishmentisonlyamarginaltechniqueadoptedtocontroltheerosion.Arecent(Hammetal.,1998)showedthatmodernbeachfillshavebeenpractisedsince1962.Duringthisperiod,about115fillsandrefillshavebeenperformedin26sitesaddinguptoatotalfillvolumeofabout12Mm(Fig.4).ThisverylimitedquantityreflectsthatmostcoastaldefenceworksinFrancestillcomprisetheconstructionofgroynes,seawalls,anddetachedbreakwaters.FrancehasacoastlineborderingboththeAtlanticOcean,withextremetidalvariationsinsomelocations,andtheMediterraneanSeawithlittleornotide.5.1.ProjecttypesandobjectivesTheFrenchapproachtobeachnourishmentistraditionallytocoupleitwithhardstructuresassupportingmeasurestominimisesandlossesandmaintenance.Inaddition,inthemostimportantnour-ishmentprojects,thenourishmentoptionwaschosenonthebasisofthedesiretogetridofavailablesanddredgedtomaintainnavigabledepthsinanearbyharbour.Aslightchangeinpolicymaypossiblybereflectedintworecentprojects(ChatellaillonandFromentine,southandnorthofLaRochelle,respec-tively,inFig.4)representinganewapproachwithmuchlesssupportingmeasuresandallowanceofanannuallossofmaterial,implyingsomeperiodicrenourishment.Projectmotivationsincludethecreationofrecrea-tionalbeaches,coastaldefence,dunerestoration,and,asmentionedabove,theuseofdredgedsandfromharbourextensionsormaintenance.Nodifferenceismadeinpracticebetweenprotectionagainstfloodingandstabilisationoftheshoreline.Ingeneral—asinItaly—themeasuresmaybeclassifiedasremedialratherthanpreventive.TheinventoryissummarisedinAppendixD.Atotalof24siteshavebeendocumentedincluding:–Nineartificialbeachesmadeofsandorgravel.Theterm‘‘artificialbeach’’isusedheretopointoutthattheshorelinehasbeenmovedseawardtoapointneverbeenreachednaturallybeforeduringthelastcentury.Suchbeacheshavebeenbuiltforrecrea-tionalpurposesbetween1962and1978.–Elevensiteshavebeennourishedinordertocontrolbeacherosion.Amongthesesites,thecaseofthebeachofAngletisunusualbecauseofthetechniqueadopted(shorefacenourishment)andofthelargevolumeofsanddepositedthere(8.2Mm1974and1992).–Oneshinglebeachhasbeennourishedperiodicallysince1969toavoidfloodingofthelow-lyingareas(LesBas-Champs).Inaddition,dunerestorationworkswerecarriedoutalongtheGulfofLionontheMediterraneancoastsince1984particularlyinthreesites(LesOrpellieres,Maguelonne,andLaGracieuseSpit)tocontrolflooding.H.Hansonetal./CoastalEngineering47(2002)81–111 Intotal,1Mmofshingle,0.3Mmofgravel,and10.5Mmofsandhavebeenusedatthesesites(totalof11.8Mm).Formostofthem,thetotalquantitywaslessthan0.1Mm(elevencases)orbetween0.1and0.3Mm(eightcases).Fivesiteshavereceivedmorethan0.3Mmintotal,andthreeofthemareregularlynourished(Bas-Champs,Anglet,andArcachonbasin).Thesethreesitesrepresent82%ofthematerialplacedonFrenchbeaches.5.2.Execution,designandevaluationDesignmethodsofcoastaldefenceworksareratherwelldevelopedinFrance.Thesurveyofthecompletedprojectshasshownthatdetaileddesignstudieshavebeenperformedfor15cases.Atypicaldesignstudyincludesthedeterminationofthedesignwaterlevelsandwaveclimate,fieldinvestigationtogetinformationonthebathymetryandbottomsedi-mentdistribution,andafirstassessmentofthepastandpresentsituationfromamorphodynamicview-point.Inasecondstep,thebeachfillitselfisdesignedincludingthehardstructuresthatwillguaranteealowlossrate.Suchadesignisbasedonclassicalcoastalengineeringconcepts1984)butalsoincludesenvironmentalconsidera-Asmentioned,manyoftheprojectsaremotivatedfromtheperspectiveofgettingridofdredgedmaterialmainlyfromportareas.Thus,grainsizevariesfromshingletofinesanddependingonthelocationprovid-ingamaterialthatmaybemoreorlesssuitableforbeachnourishment.Theuseoffinesandinseverallocations(e.g.CavalaireandAnglet)ledtomajor Fig.4.DocumentedbeachnourishmentsitesinFrance.H.Hansonetal./CoastalEngineering47(2002)81–111 losses.Thefillmaterialisgenerallyplacedonthebeachbytrucksinthecaseofshingleandpebbles,andhydraulicallyinthecaseofdredgedsand.Dunerestorationmakesuseofavailablesandonthebeach.ForthemainprojectatAnglet,ashorefacenourish-mentschemewasused.Detailedstudiesarecommonlycarriedouttoprovideamorphodynamicevaluationofthebeachtobenourished.Amobile-bedscalemodelhasbeenthetraditionaltoolinFranceinperformingmorphody-namicimpactinvestigationssincethe1950s.Scalemodelswereusedinninecasesinthe24sitesincludedintheinventory.Shorelinenumericalmodelsarealsobeingusedinrecentyearstostudylarge-scaleevolutions.Inseveralcases,insitutestshavebeenperformedtocheckthedesign.However,monitoringafternourishmentisinmostcasesnotsystematic.Themonitoringprogramisnotplannedinadvanceandisoftennotcomprehensive.Topographicsurveysarequitefrequentlycarriedoutforduneandbeachnour-ishments,butaretypicallynotcomplementedbybathymetricsurveys.Thewaveclimateisseldomrecordedbutinternationaldatabases(weatherships,satellitedata)aswellashindcasttechniquesareused.Theinventoryalsoshowedthatthekeyperform-anceindicatoristhevolumelossofsandinmostcases.AnotableexceptionisthecaseofAngletbeachwhereperiodicshorefacenourishmentsweremadeinordertomaintaintheshorelineposition.5.3.LegalandfinancialaspectsTheLawof1807specifiesthattheMinistryofPublicWorksshallcertifythenecessityofcoastaldefenceworks.Allcostsincurredforcoastaldefenceworksshallbebornebytheprotectedlandownersinproportiontotheirinterests,exceptincaseswherethegovernmentdecidesthatsubsidiesfrompublicfundswouldbeadvisableoraremerited.Inpractice,suchsubsidieshaveusuallybeenextremelysmall,owingtothelimitedfinancialresourcesgenerallydevotedtocoastaldefenceworks.Thislawalsosetsoutguide-linesfortheso-called‘‘compulsory’’associationsthatareresponsibleforhavingtheseworkscarriedoutandmaintained.Ithasalwaysbeendifficulttoputtheselawsintoeffect,whichgaverisetothesaying,‘‘Francehasnocoastaldefencesystem,onlyex-penses’’(DeRouville,1954)Since1970,thelocalgovernmentrepresentativeprovidescertificationwithpossiblefunding(10–30%)incasesofthedefenceofurbanareas.Suchfundingis,however,exceptional.TheLawof1973allowslocalcommunitiestotakeinitiativesinthisareawhencommoninterestsarethreatened.Inprac-tice,localmunicipalitiesarenowadaysinchargeofcoastaldefenceworkswithpossiblepartialfinancialsupportfromregionalauthorities.Asaconsequence,thereisnonationalcoastalmanagementinFranceandnonationalstandardforbeachfilldesignandevalua-tion.Eachprojectismanagedaccordingtoprevailingandlocalconditions.Ontheotherhand,mentalitiesareslowlychangingandmanyregionalfundersarenowbecomingawareofthenecessitytothinkregion-allybeforefundinglocally.TheLawof1977wasaimingattheprotectionofnatureandinstitutesanenvironmentalimpactassess-mentstudywhenthebudgetofworksexceeds1MECU.Furtherlegaltextsimprovedtheaccreditationprocedureincludingpublicinquiries,concertation,andadministrativeprocedureswhentheworksoccupyasurfaceover2000m.Inpractice,thefinancialthresholdisnotreachedandthesurfaceareathresholdisdifficulttodefine.Thus,nourishmentprojectsescapethislaw.Afurthertextof1979requiresanadministrativeaccreditationwhencoastalstructuresarebuiltonthecoastalpublicland.Itisworthtomentionherethatcoastaldefenceworksinthislawcovershardstruc-turesonly.So,inpractice,accreditationproceduresareseldomineffectfornourishmentoperationsinTheso-calledLittoralLawof1986extendstheconceptofcoastaldefenceworkstonaturalsiteswithanaccreditationprocedurewhenthebudgetofworksexceeds0.15MECU.Italsoforbidsnewartificialbeachdevelopmentsandprotectsthenaturalstateofthecoastline.Furthermore,thecoherencebetweentheearlierlawsandthenewenvironmentallawsneedsimprovements,whicharereportedtobeinprogress.6.BeachfillsinSpain(ES)PracticallytheentireSpanishMediterraneancoastconsistsofsandybeaches(Lechuga,1994).TheprincipalcauseoferosionalongthiscoastistheH.Hansonetal./CoastalEngineering47(2002)81–111 interruptionofthesandtransportbynumeroushar-bourinstallations.Modernbeachfillshavebeenpractisedonlysince1983.Duringthelast5yearsalone,morethan600fillsandrefillshavebeenperformedinabout400sitesaddinguptoatotalfillvolumeofabout110Mm(Fig.5).ThevastmajorityoftheprojectsarealongtheMediterraneancoast.AppendixEliststhebeachlengthsandnour-ishmentvolumesforprojectswherethesenumberscouldbeestablished.6.1.ProjecttypesandobjectivesBeachfillsareusuallydonewithoutanysupportingstructures.Insomecases,detachedbreakwatersareused.Inquiteafewcases,existingdetachedbreak-watershavebeenremovedinconnectionwiththenourishmentproject.Beinganationwhereasignifi-cantportionoftheincomeisbasedontourism,theoverallobjectiveofthesenourishmentsisconnectedtotherecreationalspaceratherthantotheexactpositionoftheshorelineortotheconcernsaboutflooding.Thus,theobjectivemaybestated:thedrybeachwidthmustexceed60matalltimesforrecreationalreasons.AsfortheFrenchandItaliancases,themeasuresaremostlyremedialratherthan6.2.Execution,designandevaluationTheoverallSpanishdesigntypemaybeclassi-fiedasprofiletranslation.Numericalorphysicalmodelshaveonlybeenusedinafewimportantprojects.Similarly,follow-upstudies,includingan-nualbathymetryandgrainsizestudies,areonlyperformedforthesemajorprojects.Inthedesignprocess,environmentalconcernsseemmoreimpor-tantthantheengineeringaspects. Fig.5.DocumentedbeachnourishmentsitesinSpain.H.Hansonetal./CoastalEngineering47(2002)81–111 6.3.LegalandfinancialaspectsThefinancialprocessesinvolvedinbeachnourish-mentareregulatedbytheShoresActof1989,accordingtowhichallbeachesinSpainareState-owned.Thisactstatesthatworkswithinthejurisdic-tionsofthecentralgovernmentshallbefinancedbyproperbudgetaryappropriationsand,ifapplicable,withcontributionsfromtheregionalgovernments,localgovernments,internationalorganisations,andprivateparties.TheShoresActimposessevererestric-tionsonbuildinganddevelopmentina‘‘protectionzone’’100–200mlandwardfromthebeach.Inpractice,almostallnourishmentsarefinancedbythecentralgovernment,because,accordingtotheShoresAct,thecoastaldefenceisstrictlyitsrespon-sibility.Insomeprojects,withamoredevelopmentalratherthatpureprotectivecharactersuchasbeach-frontpromenades,regionalandlocalgovernmentsmaycontributefinanciallyjointlywiththecentralgovernment.Inthenearfuture,moreofthecoastalworksaregoingtobeconsideredaspartofanintegratedcoastalzonemanagementprocess.AfirstexampleofthiscouldbethemanagementoftheCastelloncoastalzoneproject.7.BeachfillsintheUnitedKingdom(UK)IntheUnitedKingdom,theuseofbeachnour-ishmenttocomplementtraditionalformsofcoastaldefencebeganinthe1950s.Regionalfloodprotec-tionauthoritiesalongeasternEnglishChannelnour-ishedshinglebeachesinfrontofseawalls,usingshingle(sand,gravel,andpebbles)collectedfromaccretingbeachesfurtherdown-drift.Thisformof‘‘recycling’’ofbeachsedimentshasbeensuccessfulinextendingthelifeofseawallsforover40years(Fig.6)Nourishmentofbeachesusingsanddredgedfromthenearshoreseabedstartedin1972.Theschemesallowedanincreaseinrecreationalusageofthebeaches,aswellasprotectingexistingseawalls.Between1970and1994,atotalof3Mmofsandand4.25Mmofgravelhasbeenused,correspondingtoanannualrateofabout125,000mofsandand170,000mofgravel.After1995,rateshavein-creasedto2.5Mand550,000m/year,respectively.ThesuccessofbeachfillschemesintheUKhasledtoaneverincreasingrequirementforsandandgravelinfutureprojects.TheanticipateddemandofEnglandandWalesfortheperiodbetween1995and2015isestimatedat209Mmofshingleand224Mmofsand.ThelargestnourishmentschemesofarundertakenintheUK,onthecoastofLincolnshire,hasbylate1998involvedtheplace-mentof7.8Mmofsanddredgedfromoffshore,overalengthofsome24km.Thisvolumeisexpectedtoincreaseto9.4Mmoverthenext5yearstoallowforpresentandfuturelossesford,1998).AppendixFliststhebeachlengthsandnourishmentvolumesforprojectswherethesenum-berscouldbeestablished. Fig.6.DocumentedbeachnourishmentsitesintheUnitedH.Hansonetal./CoastalEngineering47(2002)81–111 7.1.ProjecttypesandobjectivesBeachmanagementschemesintheUK,includingnourishment,haveusuallybeencarriedouttoprotectthelandagainstfloodingorerosion.Benefitssuchasincreasedopportunitiesforrecreationandaestheticimprovementswillinfluenceratherthandominatetheselectionofanappropriatecoastaldefencescheme.Factorssuchastheinitialcost,futuremaintenancerequirements,andtheachievablestandardofprotec-tionmayindicatethatbeachnourishmentisnotthebestdefencetypeinsomesites.Thefactthatnourish-mentislikelytoimproveratherthandamagebeachesfurtherdown-driftisalsoanimportantconsiderationinEnglandandWales,wheresomuchofthedevel-opedcoastlineisalreadyprotectedbycoastaldefen-Beachnourishmenthasalsobeencarriedout,inafewcases,toreducedamagecausedbylandrecla-mationorharbours.Suchmitigationworkshavebeenrequiredbycoastaldefenceauthoritiesasaconditionforsuchdevelopmentstobegrantedwithplanningpermission.Inveryrecentyears,thedesiretomakebestuseofdredgedmaterialshasledtoseveralexperimental‘‘beachfill’’schemes.Inthese,awiderangeofsediments,frommudandsiltstogravel,hasbeenplacedonerodingintertidalmudflatsinestua-riestohelpbuildupforeshorelevels,andhenceprotectsaltmarshesandfloodembankmentsalongtheshoreline.7.2.Execution,designandevaluationInthepast,manycoastaldefenceschemesrelocatedratherthansolvedfloodingorerosionproblems,andtoavoidthis,anationalstrategyforplanningandinstal-lingdefenceshasnowbeenintroduced.Asafirststep,foreachcoastal‘‘cell’’,ashorelinemanagementplanhasbeendrawnup.Thisdrawstogetherrelevantinformationonthecoastline,onitsattributesanditsprocesses.Afterconsultations,appropriaterecommen-dationsaremadeeitherforthemaintenanceoradvance-mentoftheshoreline,orforitsretreat,whethernaturalorassisted.Whereitisdecidedthatsomeformofinterventionisdesirable,moredetailedplanningandstudyoftheparticularsiteisundertakentodecideonthemosteffectiveformofworks.Sometypeofbeachmanage-mentisalwaysconsideredatthisstage,usuallyincludingpossiblebeachnourishment.Themajorfactorsindecidingonthebesttypeofdefenceare(1)benefit/costratio(B/C),(2)feasibilityandlikelyeffectivelifetime,(3)standardofdefencethatisappropriate,e.g.thereturnperiodoffloodeventsthattheschemeisdesignedtoprevent,and(4)environ-mentalimpactsofanyproposedscheme,bothlocallyandatadistance.Asaninitialstep,averywiderangeofdefenceoptionsisconsidered,withonlythemostinappropri-atebeingrejected.Therewillthenbefurtherassess-ment‘‘rounds’’,consideringtheeconomic,engineer-ing,andenvironmentalaspectsofalltheremainingoptions.Ateachstage,thedesign,costs,andperform-anceofthevariousdefencetypeswillberefined,withsomealternativesbeingrejected,untilthebestoptionisidentified.Thedesignofabeachnourishmentschemestartsbyexaminingnearbybeaches.Thisallowsanestimatetobemadeforthecross-sectionofabeachthatwouldbe‘‘stable’’,assumingasimilarsedimenttype.Thevolumeofsedimentneededisthencalculated,andthecostsestimatedusingpastschemesandknowledgeoflocalsedimentresourcesasaguide.Asmoredetailedconsiderationofapossiblenourishmentschemepro-ceeds,themajorissuesarenormallyasfollows.(1)Theavailabilityandcostofsuitablematerialsforbeachfill.Atthisstage,discussionsareoftenstartedwithcontractorsthatmightbeabletosupplysuitablematerial.(2)Theheightandwidthoftheproposednewbeachprofile.Theseparametersareusuallycalculatedwithnumericalmodels,whichforshinglebeachesareofanempiricaltype.(3)Thelikelyrateoflongshoredriftandfutureshorelinechanges,bothlocallyandalongadjacentstretchesofcoast.Thelastoftheseconsiderationsisoftenthecriticalconcern.IntheUK,thepotentialeffectsoftidalcurrentsaswellasthewavesmayneedtobeconsidered,especiallynearthemouthsofestuariesandtidalinlets.Beachnourishmentschemeshaveusuallybeenaccompaniedbytheconstructionofhardstructures,usuallygroynes,designedtoreducethelossesofthematerialthatwasplaced.Noveltypesofbeachstructuresincludingdetachedorshore-linkedbreakwatershavealsobeenused.Thedesignofnourishmentschemeswithorwithoutstructuresisusuallycarriedoutusingnumericalmodels,todeter-H.Hansonetal./CoastalEngineering47(2002)81–111 minetheirperformanceunderstormconditionsandtheir‘‘farfield’’effects.Sometimesphysicalmodelsarealsousedtooptimisethedesignofhardstructures,especiallywheretheexistingshorelinehasacomplextopography.Thenourishmentofshinglebeacheswasinitiallyperformedwiththematerialeitherbeingdeliveredbyroadorbyseausingbottom-openingbarges.Shingleisnowalsopumpeddirectlyonshorethroughfloat-ingpipelinesorbythe‘‘rainbow’’method,wherematerialispumpedthroughatubeoverthebowofadredgerwhichitselfistakenascloseinshoreaspossibleandgrounded.Shinglebeachfillvolumeshaverangedfromaslittleas2000upto1.5MmSeafordin1987).Theprimarysourcesofbeachfillforsuchschemeshavebeenexistinginoffshoreextractionareas,originallydevelopedbyandlicensedtocompaniesdredgingforsandandgravelforuseintheconstructionindustry.Asthenumberofbeachfillschemeshasin-creased,alternativesourcesofinexpensivesedimenthavebeensought.Inlandsourceshaveincluded‘‘asdug’’sandandgravel,i.e.withnosorting,gravelthatwasnotrequiredbytheconstructionindustrybecauseitwastoolargeortoosmall,andevencrushedrock.Althoughmostnourishmentschemeshavebeenonthe‘‘opencoast’’,therehavebeenrecentexamplesonmuddyestuarialcoastlinesas(CIRIA,1996b)Somerecentnourishmentschemesrelyonaprogrammeofregularrecyclingtopreservetherequiredbeachlevels,ratherthancontrolstructures.Shingleorsandiscollectedfromthedown-driftendofthebeachandreturnedtotheup-driftcoast.Insomecases,asinglelarge‘‘terminalgroyne’’hasbeeninstalledtofacilitatetheseoperations.Itseemslikelythatthosetypeof‘‘active’’beachmanage-mentwillbecomemorecommoninthefutureasfindingsuppliesofsedimentforrechargebecomesmoredifficult.ArecentreviewofthemethodsusedintheUKispresentedintheBeachManagement(CIRIA,1996a)Oncecompleted,beachnourishmentschemeshaveusuallybeenmonitoredbyregularbeachsurveys,initiallyatshortintervalsbuttypicallyreducingtosix—monthlyorannuallyafterafewyears.Suchsurveysarecarriedoutusingland-surveyingmethods,nowincludingtheuseofGPS,sometimescomplementedbyboatsurveysoftheunderwaterbeachprofile.Aerialphotogramme-tryisusedtosurveylargeareas.Thechangesinbeachprofilesareanalysedtocalculatethetotalvolumeofmateriallost,andthisprovidesasimplequantitativemeasureofthelongevity(andcosts)ofthescheme.7.3.LegalandfinancialaspectsCoastaldefencepolicyissetbythegovernment,andthe‘‘strategyforfloodandcoastaldefenceinEnglandandWales’’(MinistryofAgriculture,Fish-eriesandFood,1993)providesadetailedviewofthepolicyframework.Thestatedaimofthepolicyistoreducetheriskstopeopleandthedevelopedandnaturalenvironmentfromfloodinganderosionby(1)encouragingtheprovisionofadequateandcosteffectivefloodwarningsystems,(2)encouragingtheprovisionofadequate,technically,economicallyandenvironmentallysoundandsustainablefloodandcoastaldefencemeasures,and(3)discouraginginap-propriatedevelopmentinareasatriskfromfloodingorcoastalerosion.CoastalprotectioninEngland,ScotlandandWalesmaybecarriedoutundertheCoastProtectionAct(1949)bylocalgovernmentauthorities.Theyarerequiredtoconsultovermajorconstructionorrecon-structionschemeswiththeenvironmentagency,neighbouringcouncils,conservationorganisations,harbourauthorities,andfisheriesbodies.Approvalsand/orlicencesmayalsoberequiredfromvariousgovernmentaldepartmentsandotherbodies.Thedepartmentresponsibleforcoastaldefenceineachregionwillgiveultimateapprovalandmayassistfinanciallywithascheme.Landowners,railwayown-ers,highway,andharbourauthoritiesmayalsounder-takecoastalprotectionworks.Suchbodiesmustnormallyconsulttherelevantcoastalprotectionauthoritybeforecommencementofworks.SeadefenceinEnglandandWalesmaybeunder-takenbytheenvironmentagencywhohastheoverallsupervisorypowerstoprotectagainstflooding,undertheWaterResourcesAct(1991).Consentfromtheappropriategovernmentaldepartmentisrequiredtoobtainfinancialassistancefromcentralfunds,andthereisastatutoryrequirementtoadvertiseanyschemeandtocarryoutanenvironmentalimpactassessmentifH.Hansonetal./CoastalEngineering47(2002)81–111 appropriate.Seadefenceworksmayalsobeundertakenbycouncilsorbyinternaldrainageboards,undertheLandDrainageAct(1991),andownersmayundertakeworksontheirownproperty.Seadefenceworksmayonlybeundertakenwiththeconsentoftheenviron-mentalagency.Fundingformostcoastaldefenceschemescomesfromthecentralgovernment,theenvironmentalagency,andlocalgovernmentauthorities.However,schemesaresometimesundertakenbythecoastallandownerswhowillprincipallybenefitfromdefen-ces.Insomecases,financialcontributionstoworksassociatedwithcoastaldefenceschemesmaybemadebytheEuropeanRegionalDevelopmentFund,byspecialinterestgroupssuchastheSportsCouncilorbycharities,suchastheNationalLottery.8.BeachfillsinDenmark(DK)TheDanishcoastlineis7400kmlong.Roughlyspeaking,therearethreedifferenttypesofcoast:(1)tidalcoastprotectedbyseadykes,(2)highlyex-posedNorthSeacoast,and(3)lessexposedcoastsoftheBalticSeaandtheKattegat(Fig.7).About100yearsago,thedunesontheNorthSeacoastwerestabilisedbymarramgrassplanting.Atthesametime,harboursandgroingroupswerebuiltwhichresultedinseriousdown-drifterosion.Thecombinedresultofthestabilisationofthedunesandtheerosionwasthatin1982,theduneshaddis-appearedorwereweakalong50kmofthecoast.Soin1982,itwasdecidedtoimplementacoastalprotectionscheme.Asaprimaryoption,theduneswerereinforced.Wherethatwasnotpossible,arevetmentwasbuilttoprotecttheremainingdune.Onhighlyexposedstretcheswhereerosionshouldbestopped,lowdetachedbreakwaterswereusedincombinationwithnourishment.Anincreasingvolumeofnourishmenthasbeenappliedsince1982.In1998,thetotalnourishmentvolumeontheNorthSeacoastswas3.6Mmandthetotalvolumeappliedsince1974was31Mm.OnthelessexposedbeachesoftheBalticSeaandtheKattegat,onlythreebeachfillprojectshavebeencarriedoutwithatotalvolumeof100,000mAppendixGliststhebeachlengthsandnourishmentvolumesforprojectswherethesenumberscouldbe8.1.ProjecttypesandobjectivesAbout97%ofthenourishmentvolumewasap-pliedonastretchoftheNorthSeacoastwheredunesprotectthelowhinterlandagainstflooding.Theback-groundforthisisthepolicythatwasformulatedin1982.Theheadlinesofthispolicywere(1)torees-tablishandmaintainasafetylevelagainstfloodingofaminimum100-yearreturnperiod,(2)tostoptheerosionwheretownsaresituatedclosetothebeach,and(3)toreduceerosiononpartsofthecoastwhereerosioninthenearfuturewouldreducethesafetyagainstfloodingtolessthan100years.Themaindesignobjectivesoftheindividualprojectsarecoastalprotection,dunereinforcementandmaintenanceofaprotectivebeach(LaustrupandMadsen,1994).Theterm‘‘coastalprotection’’meansthatthelossinsedimentisreplacedinordertostop Fig.7.DocumentedbeachnourishmentsitesinDenmark.H.Hansonetal./CoastalEngineering47(2002)81–111 orreducethegeneralretreatofthecoastalprofile.However,sofar,onlythelossesabove6mhavebeencompensated.Ascouldbeexpected,thishasledtothesteepeningoftheprofilesingeneral.Ifandhowfarthissteepeningprocesswillcontinueisbeingstudiedatpresent.Onstretcheswherethedunesareweak,newdunesarebuiltortheexistingdunesarereinforced.Itisimportanttomaintainabeachwithwidthandvolumesufficienttoprotectthedunesagainsterosionandtopreventerosionbelowacriticallevelatthefootofarevetment.InDenmark,thereisnoneedtobuildwiderbeachesforrecreationalpurposessincethenumberandtotallengthofgoodqualitybeachesarehighcomparedtothenumberofpotentialusers.8.2.Execution,designandevaluationTheprincipaldesignparametersaretheautonomouserosion,therequestedlifetime,andtheeffectivenessfactorofthenourishmentsand.Thecalculationoftheautonomouserosionisbasedonaregressionanalysisoftheerosioninthedifferentsegmentsoftheprofiles.OntheNorthSeacoast,astormwithareturnperiodof1yearmaylowerthebeachsomuchthatthebeachnolongerservesitspurposeasaprotectivebeach.Con-sequently,thepolicyistorenourishthebeachonceayear.Ifalargervolumeisplacedonthebeach,itmayaffectthequalityofthebeachinanegativeway.Full-scaletestshaveindicatedthatcoastalprotectionoftheshoreface-partoftheprofilemaybeachievedwithnourishmentprojectswithalifetimeintheorderof3Theeffectivenessofthenourishmentsandiscalcu-latedusingtherenourishmentfactor(James,1975)Thenextstepwillbetoaccountforadifferenceineffectivenessasaconsequenceofinitiallossesduetoshaping,positioning,andvolumeofthenourishment.Theerosionbetween4and6iscompensatedbyshorefacenourishment.Abuffervolumeatthedunefootisneededtopreventerosioninthedune.Sandtobeplacedonthebeachispumpedonshorethroughasubmergedpipeline.Insomecases,thesandispumpedoverthebowbythe‘‘rainbow’’methodmentionedabove.Sandontheforeshoreisplacedeitherbydump-ingorbypumpingoverthebow.Theevaluationofthenourishmentisbasedonsurveysnormallycarriedoutannuallyatcross-shorelinesatadistanceof200m.ThegeneraleffectofthenourishmentprogramisevaluatedusingsurveyscarriedouteverysecondyearalongtheentireNorthSeacoast.Here,thedistancebetweenthelinesis1km.Thesafetylevelofthedunesisrecalculatedevery5yearsbymeansofaerialphotogrammetry.8.3.LegalandfinancialaspectsOntheNorthSeacoast,theactualpolicyforsafetyassessmentanderosioncontrolisestablishedthroughagreementsbetweenlocalauthoritiesandthenationalgovernmentbasedonDanishcoastalauthorityrecom-mendations.Theagreementsarerenegotiatedevery5years.Thecostsaresharedbetweenthegovernmentandthelocalauthorities.Thegovernmenttypicallypays50–70%.Insomestretches,thegovernmentpays100%.IntheBalticSeaandKattegatcoasts,coastalprotectionisregulatedbyanactpassedin1988.Accordingtothisact,thecountiesareresponsiblefortheadministrationofcoastalprotectionprojects.Sincethecountiesdonothaveanycoastalengineer-ingexpertise,thecoastalauthorityprovidesassistanceattheplanningstageandconsultingfirmsprovideassistanceattheprojectstage.Thegeneralpractiseisthatthereisnopublicfundingforcoastalprotectioninthisregion.Here,theindividuallandownershavetocoverallcosts.Thecoastalauthorityisresponsibleforissuingpermitsforcoastalprotectionandotherstruc-turesinthecoastalzone.9.OthercountriesOfBelgium’sonly65kmofshoreline,35kmareprotectedbybeachesincombinationwithseawalls,3kmbybreakwaters(coastalharbours)andtheremain-ingpartbybeachesanddunes.Modern,large-scalebeachfillswerefirstcarriedoutin1968.Sincethen,17.2Mmofsandhavebeenusedonseverallocationsforoveratotalcoastallengthof19.5km.Tocom-pensateforbeacherosiondown-driftofZeebruggeharbour,aninitialfillof8.5Mmwasplacedover8kmofbeachin1977–1979(Kerchaertetal.,1986)Sincethen,twosmaller-scalerefillswerenecessaryin1986and1998,respectively.H.Hansonetal./CoastalEngineering47(2002)81–111 InGreece,beachnourishmentisnotacommonpracticetofightcoastalerosion.Themajorityoftheprojectsarehardmeasuresforcoastalprotection,whilethereareafewcasesofsmall-scalenourishmentcombinedwithhardstructures(jetties,groynes,etc.).Inthesecases,thevolumeofsuppliedmaterialisintheorderofafewthousandsupto10,000mInIreland,therehaveonlybeentwosignificantbeachnourishmentssince1993andverylittlepriortothisdate.ThelargestofthesewasRosslareStrand,Wexford,whichreceivedanapproximatequantityof160,000mofsandbetween1994and1996.ThesecondcasewasDonabateBeach,Dublin,whichwasnourishedbetween1993and1998withaquantityofapproximately75,000mofsand/gravelmaterial.ThefirstnourishmentinPortugalwasperformedin1950atEstoril,nearLisbon,withthedeploymentof15,000mofsand.Thefirstlarge-scaleinterventionwasdoneatAlgarveinvolvingabout0.9Mmofsand.Between1950and1997,morethan29fillswererecordedin12differentsites,addinguptoatotalfillvolumeofabout6.6Mm.About2/3ofthesevolumewasplacedalongthePortugueseSouthcoast(lowtomoderatewaveenergy)withonlyabout170km,ascomparedtothe830kmoftheWestcoast(highwaveInSweden,beachnourishmentsareveryunusualforcoastalprotection.Inthesecases,thevolumeofsuppliedmaterialisintheorderofafewthousandsupto15,000m.Inalmostallcoastalerosioncases,revetmentsorgroyneshavebeenused.EventhoughoutsideofEurope,theconditionsintheUnitedStates(US)willbeverybrieflydescribed.Thisismainlybecauseoverthepast75years,beachnourishmenthasbecomethepreferredalternativeforshoreprotectionintheUS.Asaresult,theUShasbecometheleadingcountryintheworldintermsofexperience,numberofprojects,aswellasvolumes(Basco,1999).Here,forbeachnourishmentprojectsjointlyfundedbythefederalgovernment(throughtheCorpsofEngineers)andthelocalsponsor(Stateand/orCountygovernment),theonlybenefitthatcanbelegallycalculatedtothebenefit/costratioisthestructuraldamagemitigationbenefitofwidenedbeaches(IWR,1996;Basco,personalcommunica-tion).Thestormdamagereductionisevaluatedusingnumericalmodelsforasetofdesignstormevents.Thus,focusismoredirectedtowardstheprotectivefunctionofthebeachratherthanonthebeachsystemitself.Other‘‘benefits’’cannotbeincludedinfederalprojectstocalculatetheB/Cratioatthistime.Eachsite-specificcaseintheUSisevaluatedseparatelyandmustmeetitsowntestofwhetherornotthebenefitsexceedthecosts.Thereis,however,alargebacklogintheCorpsofEngineersprojectswith�B/C1butstillnotfundedduetopoliticalandbudgetreasons.Thus,abeachmanagementplanfortheentireUSisbadlyneeded.Asaresultofthis,somestates,especiallyFlorida,haveestablishedtheirownseparatefundingsourcesforbeachnourishmentprojectswheneverandwhereveritmakeseconomicsensetodosointhelongrun.TheydonotwaitforthejointprojectofthefederalgovernmentandtheCorpsofEngineers.10.Comparativeresults10.1.RatesandvolumesTherearebigdifferencesinnourishmentratesandvolumesbetweentheinvestigatedcountries.Table1showsthenumberoffills,fillratesandvolumesforthe Table1Beachfillnumbers,ratesandvolumes(yearstarted)TotaloffillsofsitesAverageAverageFR(1962)12115261040.54.4IT(1969)1536364200.41DE(1951)50130603850.82.1NL(1970)110150307333.75ES(1985)1106004001830.31.5UK(1954)2035325700.61.1DK(1974)31118132632.49.1H.Hansonetal./CoastalEngineering47(2002)81–111 respectivecountriestogetherwiththeyearwhenmod-ernbeachnourishmentswereintroducedonamoreregularbasis.SpainandtheNetherlandsarebyfarthebiggestnourishingcountriesinEurope.ThemostdistinguishingdifferencebetweenthetwoisthatthesandintheNetherlandsisplacedonrelativelyfewlocations,whileinSpain,thesandisportionedoutoveralargenumberofsmallersites.Table2showsthepresentannualfillratesforthesecountriesandestimatesofcorrespondingvaluesforsomeothercountriesaroundtheworld.Thus,thetotalannualrateoftheEuropeancountriesaddsuptoabout28Mm,whichisaboutthesamevolumeasthatforthefederalprojectsintheUSA,i.e.wheretheUSArmyCorpsofEngineersareinvolved.IntheUSA,thereisanestimatedadditional20–30Mmperyear,ifprojectsfundedbytheState,localgovernments,andprivateinterestsareincluded.Lookingabitmoreondetailrevealsanumberofinterestingfeatures.Table3showsestimatesofnationalaveragevaluesonbeachnourishment-relatedparametersforEuropeandtheUS,where=numberofyearsofmodernbeachfills(exceptforNLwhereonlytheperiodafteradoptingthedynamicpreserva-tionpolicyisconsidered);=totalfillvolumeovertheseyears(10);LN=kmofbeachsubjecttobeachnourishmentoutofthetotalkmofsandybeaches(km)(here,eachspecificbeachsectioncountsonlyonceeventhoughitmayhavebeennourishedmanytimes);LP=totallengthofallnourishmentprojectssummedup(km)(here,thelengthofeverybeachnourishmentiscountedevenifmanyofthemareonthesamebeach);LS=totallengthofsoft(sandorgravel)materialboundaryoftheentirecountry(km);AVN=annualfillvolume(m/m/year)permofbeachnourishment=;AVP=averageunitvol-ume(m/m)forallfillprojects=/LP;AVS=annualfillvolumeperkmoftotallengthofsandybeach=;ANF=averagenumberoffillsonaparticularprojectsite=LP/LN;ARI=averagerenourishmentinterval(years)=/ANF;RUV=rangeofunitvol-umes(m/m)foreachfillproject.Themoststrikingvariationbetweenthecountriesisthelengthofcoastsubjecttonourishment(LN)relativetothetotallengthofsoftcoastline(LS).In Table2AnnualfillratesforselectedcountriesCountryAnnualfillCountryAnnualfillFR0.7UK4IT1DK3DE3JapanNL6SouthAfricaES10AustraliaUSA(Federal)Approximatenumbersbasedonoralinformationfromalargenumberofinitiatedpersons. Table3Nationalaveragevaluesonbeachnourishment-relatedparametersItemFRITDENLESUKDKUSA=numberofyearsoffills3337481013442446=totalfillvolume(10)12155060.21102031144LN=lengthofcoastlinesubjecttonourishment(km)3573128152200n/a80350LP=totallengthofallnourishmentprojects(km)19085313291525n/a515n/aLS=totallengthofsoft(sandandgravel)coastline(km)196036206022921760367050061,400AVN=annualfillvolumepermofcoastlinesubjecttonourishment(m/m/year)=10.45.61039.642.3n/a169AVP=averageunitvolumeforallprojects(m/m)=/LP63176210207210n/a60n/aAVS=annualfillvolumepermoftotallengthofsoftcoastline(m/m/year)=0.190.111.720.64.8n/a2.60.05ANF=averagenumberoffillsonaparticularprojectsite=LP/LN5.41.22.41.92.6n/a6.4n/aARI=averagerenourishmentinterval(years)=/ANF6.131.819.65.24.9n/a3.7n/aLN/LS(%)1.82.021.352.111.4n/a160.6RUV=rangeofunitvolumesforindividualprojects(m/m)3.3–40019–51130–50031–59670–450n/a10–100n/aOnlyfortheperiod1991–2000(afteradoptionofNationalDynamicPreservationpolicy).OnlyCorpsofEngineersprojects,Alaskanotincluded.H.Hansonetal./CoastalEngineering47(2002)81–111 NL,morethanhalf(52.1%)ofthesoftcoastlineissubjecttonourishmentwhereasintheUS,itislessthan1%(0.6%).InothercountriesinEurope,FRandITalsoshowlownumbers,indicatinglittlenourishmentactivityandlongsoftcoastlines.WithregardtotheAVNvalues,NLandESfillonanaverageabout40m/yearalongcoastlinessubjecttonourishmentwhereasothercountriesfillaround10/year(novalueforUK).ThiscouldindicatethatNLandESarelosingmoreoftheirfillsorthattheyaremorepersistentincompensatingalllossesofmaterial.AsimilarpictureisshownintheARIvalues,wheretheaveragereturnintervalinNLandES,togetherwithFRandDK,isabout5years,whereasthecorrespondingnumbersfortheothercountriesarearound25.AsopposedtoNLandES,however,FRandDKfilllessineachprojectasindicatedbytheirlowerAVPvalues.Allcountriesstudiedshowaverywiderangeofunitvolumesforindividualprojects.10.2.DesignparametersTables4and5showanattempttoclassifythedesignparameterstakenintoaccountintherespec-tivecountries.Table4indicatesthewave-andsedi-ment-relatedconditionsthatareincludedinthedesignprocess,wheretheparameterslistedarestorm=stormsurgelevels,=longshoresedimenttransportrates,run-up=run-uplevels,=depthofclosure,waves=waveheight(anddirection),sed.dist.=spatialdistributionofsedimentgrainsize,andaeoliantransp.=lossesofsedimentduetoaeo-liantransport.Table5showsthefillpropertiesandproceduresthatareexplicitlytakenintoaccountinthenourishmentdesign,where=bermheight,=bermwidth,overfill=theuseofoverfills,vol./m=volumeoffillpermofbeach,transi-tion=theuseoftransitionsatthelateralends,=grainsizeofborrowmaterialrelativetothenaturalsedimentgrainsize,structures=theuseofsupportingstructures,ren.period=calculatedrenour-ishmentperiod,follow-up=theuseoffollow-upprograms,andperf.eval.=theuseofperformanceevaluationprograms.11.OverallconclusionsanddiscussionOverthelastdecades,therehasbeenagradualchangefromhardtosoftcoastaldefencetechni-ques.Periodicartificialnourishmentiswidelyregardedtodayasanenvironmentallyacceptablemethodofbeachandduneprotectionandrestora-tionforshort-termurgencies(viz.storm-inducederosion)aswellaslong-termissues(i.e.structuralerosionandrelativesea-levelrise).Thepresentpaperhighlightsthefactthatsuchtendencyisneithereasytosustainnorwellestablished.Italso Table5DesignelementsintherespectivecountriesElementFRITDENLESUKDKYYYYYYYYYYYYNOverfillYYNYNNNVol./mYYYYYYTransitionNYYYYN�11�11�11StructuresYYNNY/NYNRen.periodNN5–75n/aNFollow-upNNYYY/NY/NYPerf.eval.NNY/NYNY/NY=bermheight;=bermwidth;overfill=theuseofoverfills;vol./m=volumeoffillpermofbeach;transition=theuseoftran-sitionsatthelateralends;=grainsizeofborrowmaterialrelativetothenaturalsedimentgrainsize;structures=theuseofsupportingstructures;ren.period=calculatedrenourishmentperiod;follow-up=theuseoffollow-upprograms;perf.eval.=theuseofperformanceevaluationprograms.Forsandybeachesonly.Forshinglebeachesoften1. Table4Designconsiderationsforcoastlinemaintenanceintherespectivecountries(Y=yes,N=no)ParameterFRITDENLESUKDKStormYYYNNYNYYYNYYNRun-upYNNNNYNYNNNYNYWavesYYNYYNSed.dist.YNNYYNAeoliantransp.NYNNNNConsideredforsafetynourishment,notforcoastlinemanage-H.Hansonetal./CoastalEngineering47(2002)81–111 highlightsthefactthatalargevarietyofsituationsandexperiencesexistinEurope.Parametersusedinthedesignprocessaresum-marisedandcompared.However,theyarehardtoevaluate,astheystillonlypresentwhichparametersaretakenintoaccountandnothow.Countries,suchasItaly,thatconsidermoreparametersmayseemtoperformamorethoroughdesignthanothersdo.However,itcouldalsoindicatethatthesecountriesimprovisemorefromcasetocasethanothers,suchastheNetherlands,whichhasamoreconsistentdesign.Also,thenumberofparametersthatneedstobetakenintoaccountcertainlyreflectsthedegreeofvaryingconditionsfromsitetosite,whichisofcoursesmallerintheNetherlandsthaninItalyor11.1.BeachfillpracticeThereare—asexpected—significantdifferencesbetweentheinvestigatedEuropeancountriesregard-ing(1)engineeringmethodsandevaluationproce-dures,(2)overallcoastalmanagementstrategies(whichareverydevelopedinsomecountriesandvirtuallynonexistentinothers),and(3)legalandfinancialframeworks.Thefollowingmorespecificremarkscanbemadeconcerningthedifferentnationalcharacteristics:–NLandDKaretheonlycountriesthathaveaseriousoverallperformanceevaluationprogramintegratedintotheirlegalframework.–NL,DE,DK,andUKhavedevelopedalong-termstrategyforactionsalongthecoastandthethreeformerarealsoimplementingthoroughfollow-upprograms.–EShasafairlywell-developedorganizationandalong-termphilosophyfortheiractionsbutanticipatesrunningintoproblemsoffindingsuitableborrowareasinthenearfuture.–ES,IT,andFRallapplyastrategyofremedialratherthanpreventivemeasuresandseemtosufferfromalackofoveralllong-termstrategy,coastalmanagement,regularmonitoringofthecoastline,aswellasacomprehensivesurveyofavailableborrowareas.–ITandFRsufferfromlackoffinancialsupportforregularrenourishments.–ITexperiencesunclearcommitmentsandsharingofresponsibilitiesbetweentheMinistryofEnviron-mentandtheMinistryofPublicWorks.–Allinvestigatedcountriesforeseeacontinuedtransferfromhardtosoftmeasuresandregardbeachnourishmentsasaneffectivemeansofcoastlinepreservation.–AnnualfillvolumepermofcoastlinesubjecttonourishmentisconsiderablyhigherinNLandES(around40m/m/year)thanintheothercountries(around10m/m/year).–TheaveragerenourishmentintervalisconsiderablylongerinITandDE(around25years)thanintheothercountries(around5years).–Nourishmentsareexpectedtocontinueoverforesee-ablefutureinallparticipatingcountries.ThepresentstudyshowsthatitwouldbeveryprofitableforsouthEuropeancountriestolearnaboutthenorthEuropeanpractices,particularlyregardingthelong-termcoastalmanagementandtheregularmonitoringofthecoastalmorphology.Ontheotherhand,therecentDutchexperiencehasshownthattheirlegalsystemisabitrigidleadingsometimestoalmostautomaticlocalrenourishmentsthat,strictlyspeaking,areunnecessaryinreachingtheglobalobjective.Fortunately,theystillservetopreservethecoastlineofawiderarea(Roelse,1996)TheUKexperienceofbeachnourishmentusingmixedsediments,includinggravel,maybeofinter-estelsewhereinEurope.Inconclusion,thecountriesinEuropehavealottogiveandtakefromoneanotherregardingbeachnourishmentpolicy,strategy,andmethodology.Eventhoughcontrollingconditionsarequitediffer-entbetweencountries,itwouldbeverybeneficialtoestablishaEuropeanstrategyandaEuropeanmethodologyforbeachnourishments.EventhoughtheEuropeancountriesthatdohaveanourishmentstrategyhavequitedifferentpolicies,theyallseemtobebasedonaninherentbeachpropertywhetheritisbeachvolume,drybeachwidthorshore-linelocation.Asacontrastandbriefcomparison,theconditionsintheUSarequitedifferent.There,beachnourishmentsaremainlymotivatedfromastormdamage-reductionbenefitperspective,eventhoughrecreationbenefitsarealsoconsidered.Thus,focusismoredirectedtowardstheprotectivefunctionoftheH.Hansonetal./CoastalEngineering47(2002)81–111 beachsystemratherthanonthebeachsystemitself.TheUSsystemseemsmoredynamicandflexibleinthatitismoreadaptabletolocalandvaryingcondi-tions,whereastheEuropeansystemsaremorerigid.Ontheotherhand,thesimplerrulesinsomeEuropeancountriesareeasiertoimplementonawiderscale,whichinthelong-termperspectivemaybemorecost-AcknowledgementsThisworkisundertakenaspartoftheSAFEprojectpartlyfundedbytheEuropeanCommission/DirectorateofScience,ResearchandDevelopment(DG-XII),ContractNo.MAS3-CT95-0004andbyMinisteredel’Equipement,desTransportsetduLogement/DirectiondelaRechercheetdesAffairesScientifiquesetTechniques/ServiceTechniquedesPortsMaritimesetdesVoiesNavigables(France),SubventionNo.97M/3.ContributionsabouttheconditionsintheirrespectivecountrieshavebeensuppliedbyMr.J.Casey,DepartmentoftheMarineandNaturalResources(Ireland),Mr.O.Ferreira,UniversityofAlgarve(Portugal),Mr.S.Christopou-los,AristotleUniversityofThessaloniki(Greece),Mr.P.DeWolf,MinistryoftheFlemishCommunity(Belgium)andProf.D.R.Basco,OldDominionUniversity(USA),andaregratefullyacknowledged.TheauthorswouldalsoliketoacknowledgethereviewofProf.Bascowhosecommentswereofgreathelpandimprovedthequalityofthispaper.DisclaimerFactsandfiguresgiveninthispaperarebasedoninformationavailabletoandprovidedbytheauthorsanddonotnecessarilyexpresstheopinionoftheEuropeanCommissionorthenationalgovernments.AppendixA.DetailsonselectedGermansitesA.1.Location:syltThemainaim:erosioncontrolforpreventionofunderscourat3-kmlongstretchofembankments.Hardstructures:seawallsandrevetments.Dredgers:trailinghopper(1984)andsuctionhopper(since1990).Dumpingdistances:2000m(1000-msinkerlinefromhoppertoshoreand1000malongbeach).Designsupportmethod:conclusionsfromdetailedmonitoringofpreviousfills.Performance:satisfac-tory.A.2.Location:IslandofNorderney/NorthSeaAim:from1855to1950,revetmentsincombina-tionwith30groynes,extendingnowadaystoover6kmwerebuiltinordertoprotectaresortvillagebehindthedunes.Theretreatoftheshorelinecouldbestoppedbutnottheerosionofthebeachwithinthegroins.In1950,ataskforceconcludedthatabeachraisedaboveMHWatthetoeoftherevetmentwouldbethebestsecuritymeasureforthestructure.Aninitialfillof1.25Mm(approximately200m/m)wasrecommended;furthermore,ayearlyreplenishmentof90,000mistobereplacedbyrefillsin5–10-yearintervals.ThiswasthebeginningofactivecoastalprotectioninGermany.Inover42years(1952–1994),atotalof4.3Mmofsandweredumpedonthebeach.Thisisequivalenttoanaverageyearlyfillrateof80,000mforthefirstthreedecadesand165,000mforthelastdecade(1984–1994).Theincreasecanbedirectlyrelatedtoanincreaseinstormsurgefre-quency.Stationarydredgers:cutter(1976–1984)andsuc-tion(since1989).Dumpingdistance(sinkerlinefromdredgertobeach):800–2800m.Dailydump-ingrate:15,000–30,000m.Designsupportmethod:analysisofaminimumprofileequivalenttoamini-mumvolumeof50m/maboveMLWinfrontofthestructure.Belowthisvolume,therisksofstructuraldamagesincrease.Performance:satisfactoryrelatedtocurrentefforts;refillintervalisunpredictablebecauseitisdependentonstormsurgefrequency.Highinitiallossesfromfillvolumeofmorethan200–70m/mwithin1to2yearswereexperienced.Optimizationoflosseswithoutsupportingmeasuresattheseawardgroinlimit(e.g.underwatersillsinordertotranslatethegroinfieldsinclosedunits)toreducecontinuoussandlossesduringnormaltidesresp.onlyslightlyraisedwaterlevelsintoadeeptidalgullyextendingalongthegroinheadslessH.Hansonetal./CoastalEngineering47(2002)81–111 TableA.1BasicinformationonnourishmentsonSyltLocationYearLengthVolumeFilltypePurpose/%remaining/no.ofyearsWesterland1972900100011000.35/0.44SpitIncreasebermTerrestrial–25/61978169010005900.35/0.44LinearfillIncreasebermTerrestrial–17/61984139010307400.35/0.35GirlandIncreasebermOffshore–33/61990149012008050.35/0.35GirlandIncreasebermOffshore–50/3199621407453500.35/0.50FlatspitIncreasebermOffshore–n/aNorthernpart1985480519754100.29/0.50HighbermRecessionOffshore–15/5199019009905200.29/0.40LowerbermOffshore–50/219875203005800.29/0.54SpitHousingOffshoreGeotextile199611502402100.29/0.51BarSupp.sandbagbarOffshoreArtificialSouthernpart198418403201750.38/0.29BermRecessionOffshore–10/31987288014405000.38/0.42BermRecessionOffshore–25/3199629404001350.38/0.51BermRecessionOffshore–n/an/a=notavailable.Thirtypercentlossesinfines(0.20mm)duringdumping(notincludedinfillvolumelist). TableA.2BasicinformationonnourishmentsinNorderneyandEastFriseanIslandsLocationYearLengthVolumeBorrowsiteSupporting%remaining/no.ofyearsNorderneyandEastFriseanIslands1951–1952600012502000.21/0.11BermFillinggroinWaddenarea–5/16196720002401200.21/0.20BermFillinggroinForeshore–7/9197610004004000.21/0.20BermFillinggroinTidalshoal–7/6198215004703100.21/0.20BermFillinggroinTidalshoal–10/2198417004102400.21/0.20BermFillinggroinTidalshoal–18/5198918004502500.21/0.17BermFillinggroinTidalshoal–24/3199221005002400.21/0.20BermFillinggroinTidalshoal–24/2199413003202500.21/0.20BermFillinggroinTidalshoal–n/an/a=notavailable.H.Hansonetal./CoastalEngineering47(2002)81–111 AppendixB.DetailsonselectedItaliansites TableB.2InventoryofnourishedbeachesalongtheThyrreniancoastinItaly(1991–1997)LocationYearLengthVolumePerformance/S.MargheritadiCaorle19911600130810.18/0.13n/an/aFromlandGroins+submergedLandSourcellino199611,00020001820.19/0.22n/an/aDredging32groins+submergedIsoladiPellestrina1995–1997900046005110.19/0.22n/an/aDredging18groins+submergedPortoCorsini–CasalBorsettI1988–1993600350140n/an/an/aFromland10groins+submerged(continuedonnextpage) TableB.1InventoryofnourishedbeachesalongtheAdriaticcoastinItaly(1968–1997)LocationYearLengthVolumePerformance/BorgoPrino1968–19696005083n/an/an/an/a–n/aBergeggi1970–1973n/a2000+n/an/an/an/an/a–n/aPietraLigure1971–19725004590n/an/an/aFromland–n/aLavagna197250080160n/an/an/aBypassTwogroinsn/aPortoCanalediViareggio1980–19851500400267n/an/an/aBypass–n/aLeGorette199025007430n/an/an/aFromlandSixgroins+submergedbarrierCecinaMare1987–19911433155108n/an/an/aFromlandFourgroins+submergedbarrierOstia199030001400467n/an/an/aFromlandSubmergedbarriern/aNettuno1970350031089n/an/an/aBypass–n/aTerracina1993900050056n/an/an/aDredgingSevengroins+submergedbarrierS.FeliceCirceo1995–199750002000400n/an/an/aFromlandSubmergedbarriern/aSabaudia1988–1991n/a250n/an/an/an/an/a–n/aFormia19911200200167n/an/an/aFromlandOnegroin+submergedbarrierMinturno-Scaurin/an/a100n/an/an/an/an/aOnegroin+submergedbarrierPaolaS.Lucido199357001100193–/0.35n/an/aDredging18groins+submergedbarrierCalaGonone1994–19971700170100n/an/an/aFromland–n/an/a=notavailable.H.Hansonetal./CoastalEngineering47(2002)81–111 TableB.2( LocationYearLengthVolumeLidoDante–Marinadi1988–19914500900200n/an/an/aFromland17groinsn/aFoceFiume1988–19912500350167n/an/an/aFromland25groinsn/aCesenatico198480065+81n/an/an/aFromlandTwogroins+submergedRiccione198610007575n/an/an/aFromlandSubmergedMisano(FO)19841600180113n/an/an/aFromland26groins+submergedFiumeEsino–FossoRubiano1984680n/an/an/an/an/an/aThreegroins+submergedPortoRecanatin1983–198470016230.14/0.20n/an/aFromlandTwogroins+submergedGrottaSeaarea1983–1984120023190.1/1.0n/an/aFromlandSixgroins+submergedS.BenedettodelTronton19845503156n/a/1.0n/an/aFromlandThreegroins+submergedn/a=notavailable.AppendixC.DetailsonselectedDutchsites TableC.1SelectednourishedbeachesalongtheDutchcoastLocationYearLengthVolumeFilltypePurpose/SupportLifetimeAmeland-1980600022003670.16/0.18SeawardduneenforcementSafetyChannelWesterpad-Jan199046009702110.16/0.19SeawardduneenforcementSafetySeabottom–n/aAmeland-199213002301770.16/0.19DuneenforcementSafetySeabottom–5Ameland-1992810014421780.16/0.20BeachnourishmentCoastlinepreservationSeabottom–5Eierland1979560030895520.16/0.20BeachnourishmentSafetySeabottom–5DeKoog1984587030215150.20/0.19BeachnourishmentSafetySeabottom–10Eierland1985500028495700.20/0.18BeachnourishmentSafetySeabottom–5Eierland1990501025435080.20/0.18BeachnourishmentSafetySeabottom–3H.Hansonetal./CoastalEngineering47(2002)81–111 LocationYearLengthVolumeFilltypePurpose/SupportLifetimeDeKoog1991527020093810.20/0.30BeachSeabottom–5Eierland1994280013314750.21/0.30BeachSeabottom–5Callantsoog19767753424410.20/n/aDuneenforcementSafetySeabottom–10Callantsoog197916504702850.25/0.18DuneenforcementSafetySeabottom–10Callantsoog1986290012424280.25/0.18BeachSafetySeabottom–15Callantsoog1986300782600.25/0.27DuneenforcementSafetySeabottom–15Zwanenwater1987434517464020.25/0.27BeachSafetySeabottom–15Zwanenwater19873140168540.25/0.27DuneenforcementSafetySeabottom–15n/a=notavailable.TableC.1( TableC.2SelectednourishedbeachesalongtheDutchcoastLocationYearLengthVolumeFilltypePurpose/SupportLifetimeCallantsoog199130005381790.25/0.27BeachSeabottom–5Petten199121803711700.22/0.30BeachSeabottom–5DenHelder19926500615950.22/0.30BeachSeabottom–5DenHelder199324002801170.24/0.30BeachSeabottom–5Kopvan1987240019748230.24/0.30Beachn/aChannelmaintenanceWestenschouwen1991543026724920.22/0.22Beachmaintenance–n/aWestkapelle-Joossesweg198481090111n/a/0.21SeawardduneenforcementSafetyChannelmaintenance–n/aBoerenhof1988990230232n/aBeachn/aChannelmaintenance–n/aJoossesweg198829075259n/aSeawardduneenforcementn/aChannelmaintenance–n/aZoutelande19881000153153n/aSeawardduneenforcementn/aChannelmaintenance–n/aWestkapelle-Zoutelande1990129210581n/aBeachSafetyChannelmaintenance–n/aWestkapelle-Zoutelande19914100788192n/aBeachmaintenance–n/aVijgeter19921900192101n/aBeachmaintenance–n/an/a=notavailable.H.Hansonetal./CoastalEngineering47(2002)81–111 TableD.1InventoryofnourishedbeachesalongtheAtlanticcoastofFrance(1962–1995)LocationYearLengthVolumePerformancelesBains19786002003330.2/0.5Beachn/aDredgedTwobreakwatersNourishmentonlyintheareabyBWlesBains19885001603200.2/0.5Beachn/aDredgedThreebreakwatersBas-Champs1969/199440009009n/a/shingleBeachn/aBeach51groynesEffectivedevelopmentof4kmCriel1979/199450015020n/a/shingleBeachn/aBeachFiveBeachincriticalstate1978900160180n/aBeachn/aDredgedOnemaintainedbetween1978and1983LaNoveillard-197220040200n/aBeachn/aDredgedTwoSatisfactoryPlagedes1996200840n/aBeachn/aMarineTimberFromentine1989500501000.24/45Beachn/an/aWoodenfences+11,500msince1989LaRochelle/lesMinimes1967300n/an/an/a/0.77Beachn/aDredgedTwoBeachisstillinplaceChatelaillon1989–199110003503500.15Beachn/aMarineOneSandlossesaretailingoffBourcefranc1993125011793n/a/0.31Beachn/aDredgedFourbuiltbeforeMaximumof2.4mArcachonwest1976/1991150052623n/aBeachn/aDredged–RenourishmenteveryyearArcachonnorth1978/9180010110n/aBeachn/aDredged–n/aAnglet-Bayonne1974/9212008200380n/a/0.22Shore-facen/aDredgedSix1980shallownourishment,verypositiveSaint-Jean-1971–73750801070.33/n/aBeachn/aBeachTwogroynes+breakwatersThesandhasbeenwashedawayn/a=notavailable.AppendixD.DetailsonselectedFrenchsitesH.Hansonetal./CoastalEngineering47(2002)81–111 AppendixE.DetailsonselectedSpanishsites TableE.1SelectednourishedbeachesalongtheMediterraneancoastofSpainLocationYearLengthVolumePerformance1990600145241n/aBermDeltarecessionn/an/an/a(continuedonnextpage) TableD.2InventoryofnourishedbeachesalongtheMediterraneancoastofFrance(1962–1995)LocationYearLengthVolumesPlage1982–1983n/a16n/an/aBeachn/aBeachNoneErosionstabilisedafternourishmentLesOrpellieres1984–198580045n/aDunen/aBeachWoodenfences+Localbeachwidening;generalMaguelonne1986–199011,000373.3n/aDunen/aBeachWoodenfences+SchemeresistedstormswellLaGracieuse1988–199340005012.50.18/n/aDunen/aBeachWoodenfences+ThespitisnolongersubmergedLePrado1975–19901300150115n/aBeachn/aTerrestrialThreebreakwatersNoadditionalsupply;redistributedbeforeLaCiotat1975–19777003144n/aBeachn/aTerrestrialTwogroynes+twobreakwatersRidgeredistributedbeforesummer;sandaccumulatedLeMourillon197710005050n/aBeachn/an/aTwobreakwaters+submergedbreakwaterAygulf1989500200400n/aBeachn/aDredgedThreebreakwaters10timesmorebatherscanbeaccommodatedCavalaire1968/197130050550.2/n/aBeachn/aDredgedThreegroynesDepositiononanotherbeach:materialnotLaCroisette1962–196410401251200.25/n/aBeachn/aTerrestrialThreegroynes1stmaintenanceresupply(2400min1989LeLarvotto1965–196745080180n/aBeachn/aTerrestrialThreebreakwaters5000mplacedin30years+transfersn/a=notavailable.H.Hansonetal./CoastalEngineering47(2002)81–111 LocationYearLengthVolumeTorroxBeach,19911700476280n/aBermErodingduneswithhousesn/an/a199070012001714n/aBermErosionn/an/an/a19901500415276n/aBermErodingbeachwithhousesn/an/an/a199025001700680n/a/0.4–0.6BermErodingbeachwithhousesOffshore,25mdepthbreakwater199142001000238n/aBermErosionn/an/an/a19912200700318n/aBermn/an/an/an/an/a=notavailable.TableE.1( TableE.2SelectednourishedbeachesalongtheAtlanticcoastofSpainLocationYearLengthVolumenative/borrowPerformanceCastroUrdiales1988600326543n/a/0.1–0.8BermNewbeachn/an/an/aOranBeach,LaCorun19891450510352�n/a/1BermWidenslowlyerodingbeachn/an/an/aSanCosme,n/a1000400400variableBermErosionn/an/an/aLaAntilla19842500400160n/aBermWidenerodingn/an/an/a199585011001294n/a/0.33BermNewbeachSea15kmn/a=notavailable.AppendixF.DetailsonselectedsitesintheUnitedKingdom TableF.1InventoryofnourishedbeachesalongthecoastofUnitedKingdom(1972–1998)LocationYearLengthVolumeSupportingPortobello19721500160120n/a/1.35BayReactionDredged(nearshore)Sixgroynes80%leftby1988H.Hansonetal./CoastalEngineering47(2002)81–111 G.1.Location:LønstrupA1.1-kmstretchwithavillageontopofa25-mhighsand/claycliff.Theaveragecoastalretreatrateis1.4m/year.Theinitiationofthecoastalprotectionschemewasanincreasingriskforanumberofthehouses.Duringastormin1981,5–15mofthecliffwaserodedwhichacceleratedthefinaldecision.Theobjectiveoftheprojectwastostoptheretreatofthecliffinstantaneouslyandtomaintainthissituationinthefuture.Aninitialbeachnourishmentof58,000mperformedin1983(53m/m)infrontofarevetmentbuiltin1982.Inthefollowingyears,renourishmentprojectsofabout20,000m(18m/m)peryearwereimplemented.Theaveragewas0.315mm.Theheightofthebeachtodayisthesameasintheinitialsituation,whichmeansthattheaverageannuallossesareequaltotheaverageannualnourishment,inagree-mentwiththeprojectionsestimatedinthedesign(LaustrupandMadsen,1994)Prefillmonitoringcomprisedprofilesfromclifftoptoabout20mdepthwithanintervalofabout1kmmeasuredatleasteverysecondyearsince1970.Postfillmonitoringwasperformedsince1983,afterwhichthebeachhasbeensurveyedfourtimesperyearatlineswithamutualdistanceof25m.Inthesameperiod,abathymetricsurveywithalineintervalof100mhasbeencarriedouteveryyear.G.2.Location:Fjaltring–TorsmindeTheprojectsiteislocatedontheleesideofalargegroynesystemwithanaveragecoastalretreatrateofabout10m/year.Apartofthestretchisanarrowlandspitwithapotentialbreachrisk.Thebackgroundforthedifferentcoastalprotectionschemescarriedoutsincethelate1970swastheerosionriskforsomehousesandfarmsandthebreachriskforthesanddikeonthelandspit.Theobjectiveoftheprojectwastostopthecoastalretreat.Nourishmentprojectswithincreasingvolumeshavebeenimplementedsincetheearly1980s.Intheperiod1993–1996,anEU-spon-soredprogramwiththeobjectiveofcomparingabeachwithashorefacenourishmentwasimplementedonthestretch.In1997and1998,a2-Mmshorefacenourish-mentwascarriedoutat5–6mdepthontheouterbar(400m/m).Theaveragewas0.4mm.Initialandfurtherlosseshavenotbeenanalysedyet.Alargenumberofbathymetricsurveyshavebeencarriedoutonthestretchsince1938givingadetailedpictureofthenaturaldevelopmentpriortotheproject.Postfillmonitoringwasperformedthroughbathymetricsurveysandsedimentsamplingevery2monthsinlineswithamutualdistanceof200m.TableF.1( LocationYearLengthVolumePortobello1988150010067n/a/1.35BayTopupDredgedSixgroynesn/aSeaford198714502500580n/a/1.0LinearReactionDredged(offshore)Terminalgroyneand&#x-163;&#x.500;100%leftafter10yearsHurstspit19963000300100n/a/1.0LinearReactionDredgedRecyclingn/aSandBay1983/842200320145&#x-163;&#x.500;n/a/1LinearReactionDredged(offshore)SandfencingNolossafter7yearsandlittlesincethenMablethorpe1996/199824,0007500312n/a/0.3LinearReactionDredged(offshore)n/an/an/a=notavailable.AppendixG.DetailsonselectedDanishsitesH.Hansonetal./CoastalEngineering47(2002)81–111 Anonymous,1990.ANewCoastalDefencePolicyfortheNether-lands.MinistryofTransportandPublicWorks,Rijkswaterstaat.103pp.Basco,D.R.,1999.OverviewofbeachengineeringintheUnitedStatesofAmerica.FinalReport,OldDominionUniversity.Benassai,E.,Gentilomo,M.,Ragone,A.,Setaro,F.,Tomassichio,U.,1997.Littoralrestorationbymeansofprotectedbeachnour-ishment—recentItalianworks.PIANCBulletinNo.94,PIANC,pp.43–55.CIRIA,1996a.BeachManagementManual.In:Simm,J.D.,Brampton,A.H.,Beech,N.W.,Brooke,J.S.(Eds.),Report,vol.153.ConstructionIndustryResearchandInformationAsso-ciation,London.448pp.CIRIA,1996b.In:Humphreys,B.,Coates,T.,Watkiss,M.,Harri-son,D.(Eds.),Beachrechargematerials—demandandresour-ces.Report,vol.154.ConstructionIndustryResearchandInformationAssociation,London.174pp.CUR,1987.ManualonArtificialBeachNourishment.CentreforCivilResearchCodesandSpecifications,Recommendation,vol.1.Rijkswaterstaat/DelftHydraulics,TheNetherlands.DeRouville,A.,1954.Remarquesgeralessurlesmemoirespresentespourladefensedescotes.Proc.5thInt.Coast.Eng.Conf.,ASCE,432–440
 Dette,H.H.,1998.BeachfillpracticeinGermany.SAFEReport,2ndAnnualWorkshop.CommissionoftheEuropeanCommun-ities,Sylt,Germany.Dette,H.H.,Ga¨rtner,J.,1987.ErfahrungenmitderVersuchssand-lungvorHo¨rnumimJahre1983.DieKuste,Heft45(inHamm,L.,Billard,N.,Viguier,J.,l’Her,J.,1998.Lesrecharge-mentsdeplageenFrance.InternalreportSogreahIngenierieno.518904R13.Grenoble,France(inFrench). TableG.1StatisticsforallnourishmentprojectsalongDanishNorthSeacoastin1998LocationYearLengthVolumenative/borrowSkagen199830005518n/a/0.4Beachn/aLandn/an/aLonstrup199811003532n/a/0.31Beachn/aBeachn/an/aAggerTange19983700438118n/a/0.4Shorefacen/aOffshoren/an/aAggerTange199830030115n/a/0.4Beachn/aOffshoren/an/aTange1998370026171n/a/0.4Beachn/aOffshoren/an/aVristFerring1998410037591n/a/0.4Beachn/aOffshoren/an/aVristFerring1998110010091n/a/0.4Shorefacen/aOffshoren/an/aTransTorsminde19983700768208n/a/0.4Shorefacen/aOffshoren/an/aTorsminde1998610021836n/a/0.3Beachn/aMaintenancen/an/aN.HolmslandTange1998230016070n/a/0.45Beachn/aOffshoren/an/aS.HolmslandTange19988400953113n/a0.4Beachn/aOffshore+n/an/an/a=notavailable. TableG.2StatisticsforallnourishmentprojectsalongDanishBalticSeaandKattegatcoastsin1998LocationYearLengthVolume19983002583n/aBeachn/aOffshoren/an/a199810003131n/aBeachn/aBeachn/an/aHorn-baeck19983001343n/aBeachn/aBeachn/an/an/a=notavailable.H.Hansonetal./CoastalEngineering47(2002)81–111110 Hamm,L.,etal.,2002.ASummaryofEuropeanexperiencewithShorenourishment.CoastalEngineering47,237–264(thisissue).IWR,1996.AnanalysisoftheU.S.ArmyCorpsofEngineersshoreprotectionprogram.InstituteofWaterResources,IWRReport96-PS-1,U.S.ArmyCorpsofEngineers,FortBelvoir,VA.James,W.R.,1975.Techniquesinevaluatingsuitabilityofborrowmaterialforbeachnourishment.ReportTM60,USArmyCorpsofEngineers,CoastalEngineeringResearchCenter,Vicksburg,Kerchaert,P.,Roobers,P.P.L.,Noordam,A.,DeCandat,P.,1986.ArtificialbeachnourishmentonBelgiumeastcoast.J.Waterw.PortCoast.OceanEng.,ASCE112(5),560–571.Laustrup,C.,Madsen,H.T.,1994.Designofbreakwatersandbeachnourishment.Proc.24thInt.Coast.Eng.Conf.,ASCE,1359–1372.Lechuga,A.,1994.Littoraldynamicsandshorelineerosion:se-lectedSpanishcases.U.S.–SpainWorkshoponNaturalHaz-MinistryofAgriculture,FisheriesandFood,1993.StrategyforfloodandcoastaldefenceinEnglandandWales.MAFF/WelshOffice,MAFFPublicationsPB1471.Posford,D.,1998.ReviewofLincshorenourishmentstrategystudy.ReportPreparedfortheEnvironmentAgency,AnglianRegion,October1998.Roelse,P.,1996.EvaluationofsandnourishmentsattheDutchcoast1975–1994.ReportRIKZ-96.028,NationalInstituteforCoastalandMarineManagement/RIKZ,pp.72(inDutch).SPM,1984.ShoreProtectionManual,2nded.U.S.ArmyCorpsofEngineers,CoastalEngineeringResearchCenter,USGovern-mentPrintingOffice,Washington,DC,2Vols.Zaggia,R.,1998.AnalisicriticadegliinterventidiripascimentoinItalia.DegreeThesis,UniversitadiPadova,FacoltadiIngegne-ria,DipartimentodiIngegneriaIdraulica,MarittimaeGeotecn-ica,pp.160(inItalian).H.Hansonetal./CoastalEngineering47(2002)81–111111