外文翻译---台湾地区的水土保持生态工程方法

附录EcologicalengineeringmethodsforsoilandwaterconservationinTaiwanHuei-LongWuaandZheng-yiFengbaSoilandWaterConservationBureau,CouncilofAgriculture,NantouCity540,TaiwanbDepartmentofSoilandWaterConservation,NationalChungHsingUniversity,Taichung402,TaiwanAbstract:ThispaperdescribesthedevelopmentofTaiwan'slocalizedecologicalengineeringmethodstomakethemitigationworksmoreeffective.Tostrengthenthesoilandwaterconservationandprotectionoftheecologicalenvironment,comprehensivemitigationplanningisnecessarywithconsiderationsthatincludebalancingthesafety,ecology,andlandscape,andtreatingthewholewatershedasaunit.TodemonstratetheachievementofthepromotionoftheecologicalengineeringmethodsinTaiwan,thispaperillustratestwocompletemitigationexamplesforadebrisflowtorrentandastream.Mostofthemitigationworkshavesurvivedandarestillstable(withsomeminordamages)afterthetwostrongtyphoonsof2004.WeshowthatthedevelopedecologicalengineeringmethodsareverysuitableinmitigationandworthwhileforfurtherpromotionforTaiwan'secologicalenvironment.Keywords:Waterandsoilconservation;Ecologicalengineeringmethods;Hazardmitigation;Habitat;ErosioncontrolArticleOutline1.Introduction2.Ecologicalengineeringmethodsandhabitats2.1.Thefunctionsofecologicalengineeringmethods2.2.Thefunctionsoftheecologicalcorridor2.3.Somedrawbacksofconventionalengineering3.Planninganddesignofstreammitigationusingtheecologicalengineeringmethods3.1.Fundamentalconcepts3.2.Theprinciplesofintegrateddesignforstreams4.SelectedexamplesoftheecologicalengineeringmethodsofTaiwan5.InspectionoftheecologicalengineeringmethodsinTaiwan6.IntegratedmitigationfordebrisflowTorrent—anexampleofHua-shanCreekinGu-kengCounty,Taiwan7.Integratedmitigationforastream—anexampleofDing-zi-lan-kengCreekinTaipeiCounty8.ChallengeforpromotingecologicalengineeringmethodinTaiwan9.ConcludingRemarksAcknowledgements1.IntroductionOneoftheimportantmeasuresinsoilandwaterconservationinTaiwanistheecologicalengineeringmethod.Itcanbeanindexofprotectionandrestorationforecology.In2001,theSoilandWaterConservationBureau(SWCB)inTaiwanbegantopromotetheinnovativeecologicalengineeringmethods.Disasterprevention,ecologicalconservationandrecreationhavebeeninterwovenbytheadoptionofecologicalengineering.Ecologicalengineeringmethodsaresuitableforregionswithmediumsizefloodingpotentials.Theycanbeusedtoregulatestreamcourse,guidedangerouscurrenttofloodplainordetentionpondsforsafety,andreducesomesweepingforcesofrapidcurrents.Themethodshouldnotbeconsideredacompletefloodcontrolmeasure.Withdebrisflowtorrentsorveryrapidstreamflow,conventionalengineeringmaybeinevitabletomaintaintheoverallstabilityofareasvulnerabletolandslidesordebrisflow,andtocontrolanydebrisoverflow.Ifthemuchstrongerconventionalstructuressuchasslitdamsandcheckdamsareindicated,environmentfriendlyconsiderationsshouldbemadeasmuchaspossiblewhilebuildingthem.Whentheunstablehazardzoneisproperlyprotectedbyconventionalworks,theriskofwashout/failureofthemuchmoreflexibleecologicalengineeringmethodscanalsobereduced;andthefunctionsofecologicalengineeringmethodscandevelopfasterandhelptheenvironmentandhabitatstorestoregradually.Thisislikean“ecologicaltherapy”tonursetheoncedamagedenvironment.Forecologicalengineering,twomajorapproacheswereadopted:developnewtechniquesandapplynewlydevelopedecologicalengineeringmethods.Thetasksforpromotingecologicalengineeringmethodsincludethedevelopmentofreferencedrawingsforecologicalengineeringmethods,ecologicalinvestigations,habitatimprovement,establishmentofecologicalindexes,developmentofvegetation\nmethodsinlandslideareas,andholdingaseriesofconferencesforecologicalengineeringmethods.Themethodsarecreatedtosuitthedomesticbiologicalandenvironmentalconditions.Themeritsofecologicalengineeringmethodslieintheemphasisofcomprehensiveconsiderationsinallaspectsforsoilandwaterconservationtasks.Thispapershowsthatecologicalengineeringcanbeproperlyappliedtomitigationofwatersheddisasters,protectionandrestorationofecology.Inaddition,recreationinfrastructures,ruralcommunity,andagriculturaleconomiccanbesimultaneouslydeveloped.2.Ecologicalengineeringmethodsandhabitats2.1.Thefunctionsofecologicalengineeringmethods(1)Improvingtherevivalabilityofecosystem(forlargescalehazardssuchaslandslideanddebrisflow):Ecologicalengineeringmethodscanbesuitableformitigationoflargescalenaturalhazardsiftheworksaredesignedtoprovidetheabilityofrevivificationforthenaturalenvironment,ecosystem,andthecorrespondingperipheralcharacteristics.(2)Improvingtheprotectiveabilityofecosystem(formediumscalehazardssuchasscouringofstreambankandstreambed):Themethodsshouldconsiderporousmaterialsthatwillformmanyvoidstoprovideshelterandprotectionforbothaquaticandterrestrialanimals.Themitigationshouldconsideroverallcharacteristicsofwatershedsandmaintaintheconnectionstotheoriginalnaturalstreamenvironment,andavoidchangingthecurrentecosystemorasinglepurposeconstruction.(3)Improvingtherecoverabilityofecosystem(forsmall-scalehazardssuchassurfaceerosion):Originallocalmaterialssuchaslocalstones,localwoods,andlocalplantsshouldbeadoptedformitigationandthemethodsshouldhavetheabilitytoimprovetherecoverabilityofecosystem.(4)Improvingthefunctionsofstreams(forthestreamswithmitigationdone):Designofstreammitigationandrehabilitationshouldconsiderincorporatingthelocalenvironment,potentialpurposeofrecreationandcompatibilityoffutureresidentialconstruction.Thefunctionsofstreammitigationscanbeimprovedwiththeincorporationoftheecologicalengineeringmethodssuchasbuildingrecreationalarea,scenicstreambank,andecologicalbufferzone.2.2.ThefunctionsoftheecologicalcorridorTheobjectiveofcreatinganecologicalcorridoristoretainorrebuildthemajorroutesforlocalfauna'sneedsforsurvival,breeding,food,andmigration.Theroleoftheecologicalcorridorincludesconduit,habitat,filter,barrier,source,andsink(Noss,1991).SomeexamplesofecologicalcorridorsinTaiwanarediscussedbelow.(1)ImprovementoflongitudinalecologicalcorridorIn2003,atLiu-chungCreekinTainanCounty,alongitudinalecologicalcorridor(afishpassage)aswellasasedimentcontrolcheckdamwereconstructedupstream.Acensusoffishspecieswasconductedatpre-construction,during-construction,andpost-construction.Thepre-constructioninvestigationshowsfewerfishesexistedintheupstreamdueto1.3 mgapinthecreek,whichpreventedfishfrommigratingupstream.Afterthecorridorwasimplementedwithafishpassage,thenumberoffishintheupstreammeasurablyincreased.Inaddition,fishappearedmoreactive.Thismaybebecausetheswimmingspacehasexpandedandthechanceofinbreedinghasbeenminimized.(2)ConstructionoflongitudinalcorridorHou-fan-zi-kengCreekislocatedinTaipeiCountyinnorthernTaiwananditisabundantwithvariousspecies.InJuly2001,TyphoonNaricausedthecollapseanderosionofthebanks.Thecreekchangeditscourseandcausedseveresedimentation.Thehabitatsinthecreekweredestroyedandthesurvivalofmanyaquaticanimalswasthreatened.Inordertorevitalizetheecology,non-cementbasedecologicalengineeringmethodswereused,includingwood-logpileshoringforbankprotectionandarc-shapestonestreambedsillforthelongitudinalcorridor.Itisalsohopedtorebuildthenaturalsceneryofthestream.Toprovideasuitablehabitat,themeanderingofthecreekwasdesignedtocreatevariousaquaticenvironmentssuchas\npool,shoal,riffle,backwater,andslack.Basedonthecomparisonofpre-andpost-constructioninvestigations,fishandshrimphavereturnedtothecreekandincreasedinlargenumbers.Theobstacle-freearc-shapestreambedsillsandtheslackshelpfishmigratingbetweenupstreamanddownstream.(3)ImprovementoflateralcorridorusinggentleslopesInthedebrisflowmitigationatChung-hoVillageinTaipeiCounty,gentleslopesofstreambankprotectionweredesignedtofitthetopographicalflatarea.Thegentleslopesserveasaninteractionbaseforbothaquaticandterrestrialanimalsensuringthecontinuityofthelateralcorridor.(4)ExampleofpitfallsduetolackinggentleslopeThebankmitigationdesignfordebrisflowofDa-tsu-kengCreekinTaipeiCountywas1:1slopingwithslitdams.Therewasnodesignatedgentleslope.Whenadeerenteredthecreekforfood,itfellintothechannelwhichis3 mlowerthanthebankandcouldnotclimbbackupbyitself.Outoffear,thedeercriedoutanddasheddowninthecreek.Withgreateffort,peoplerescuedit.Thisshouldteachusalessonabouttheimportanceofhavingagentleslopezoneandecologicalcorridor.2.3.SomedrawbacksofconventionalengineeringNaturalstreambanksallowwaterseepage.Organicmatterandmineralsinthegroundwillbecarriedbygroundwaterenteringastream.Naturalporousmaterialsenabletheexchangeofwater,whichmaintainswaterquality.Usingconcreteinpreventingfloodanderosionisconsideredsaferthannaturalstreambanks.However,itwillbreakthecontinuityofgroundwater.Also,somechannelizedstreamswerebuiltwithsmoothverticalconcreterevetments.Suchdesignwillcauseproblemssuchasdifficultyinplanting,fishmigration,andamphibiousreptiletravel.Tallslitdamswillcutofflongitudinalecologicalcorridors.Foraperennialstream,aslitdamwillblockfishmigration.Afishpassageshouldbeconsidered.Checkdamswithdropshigherthan1 mcanhinderfishmigrationalso.Forflowregulationworks,aconcretepavedstreambedwillmakepool,shoal,andriffledisappear;andwaterqualitywillbeeasilydegraded.3.Planninganddesignofstreammitigationusingtheecologicalengineeringmethods3.1.Fundamentalconcepts(1)Considerbalanceinsafety,ecologyandlandscapeConsiderthepriorityandbalancingofsafety,ecologyandlandscapeaccordingtotheregionalcharacteristics.Safetyshallbethefirstconsideredforthehillslopesnearurbanareas.Incontrast,ecologyshouldbethemajorfactorformountainhillslopeswithvariousecologicalsystems.Forotherareassafety,ecologyandlandscapeshouldevenlyconsidered.(2)DevelopsuitablemitigationaccordingtolocalenvironmentCreateintegrateddesigntobecompatiblewithlocalenvironmentssuchasregionalecologicalresources,naturalhazards,environmentalcharacteristics,landscapescenery,historicmonuments,andresidentopinion.(3)PerformintegratedplanninganddesignforwatershedsPlanhazardmitigationandrehabilitationbytakingwatershedsasawholeunitincluding,buildingnaturalecologicaldistrict,environmentalprotectionarea,improvinghabitats,andrecreationareas,etc.(4)CreateaqueousenvironmentsConstructfacilitiesforaqueousecologicalenvironmentssuchaspool,shoal,riffle,backwater,slack,flowdeflectors,fishpassage,andartificialwetland.Buildingboulderrevetmentandrearrangingexistingrocksinstreambedisanexcellentmethodtocontroltheflowspeedandtocreatetheaboveaqueousenvironments.(5)Createtheterrestrialenvironment\nConstructfacilitiesforterrestrialecologicalenvironmentssuchasvegetation,garden,andterrace.3.2.Theprinciplesofintegrateddesignforstreams(1)BuildanaturalecologicalenvironmentProvidenearnatureworkswhichhelppool,shoal,rapids,riffle,slack,backwater,andfloodterraintodevelopnaturally.(2)DesignflooddetentionpondsaccordingtolandformsInmitigationofstreamswecanuseopenareas,suchasfloodterrain,playground,wetland,agriculturalpond,terraces,asflooddetentionponds.(3)ComplywiththeoriginalcourseofstreamsItisimportanttocomplywiththeoriginalcourseofastreamforstreambankmitigationandavoidequal-widthorparalleldesignforchannel.(4)AvoidinterferingwithhabitatsTobetterpreservehabitats,necessaryconstructionshouldbeplannedawayfromecologicallysensitiveareasthatmightbeaffected.(5)DesigngentleslopesforstreambanksInordertoprovidetheecologicalcorridorforinterchangesbetweenaquaticandterrestrialanimalsagentleslopeofstreambankslessthan1V:1.5Hissuggested.(6)PutstonesinstreamcoursesandstreambankstogenerateporosityandvoidsThevoidsbetweenstonescreatesheltersandhabitatsforanimals.Foraquaticanimalstofindshelter,forage,rest,sleep,andbreed,thehabitatsconstructedbyconcretestructurecanbeimprovedbyaddingsurfacestones.(7)Obeythefollowingfiveprinciplestoefficientlyreducetheconstructionimpactsonenvironmentsa.Useporousmaterialsonstructurefacestocreateroughnessandvoidstoenhancehabitats.b.Lowerheightofdamsandminimizesizeofstructures.c.Makeslopesofstreambanksgentletocreateecologicalcorridors.d.Usenaturalmaterialsinconstructionfordiversity.e.Makeinterfacesbetweenstructuresandmakepermeablegroundforwatercirculation.4.SelectedexamplesoftheecologicalengineeringmethodsofTaiwanSelectedexamplesoftheecologicalengineeringmethodsofTaiwanareintroducedasfollowing.(1)StonerevetmentThemainpurposeofstonerevetmentistoprotectthetoeofstreambankandavoiderosion.Inparticularitcanpreventpipingcausedbyseepage.Well-constructedstone-pavedrevetmentcanbeconsideredaretainingwallthatwithstandsactiveearthpressureofstreambank.Stonesandthefinishedsurfaceshaveanaturalappearance.Thespacesandvoidsbetweenthestonesareadvantageoustohabitatsandbettervegetationthanconcreterevetment.Thebeststonesarethosewasheddownthestreaminthepastorbydebrisflows,thussavingmoneyandtimefromtransferringstonesfromsomewhereelse.Anotherbenefitofusingstonesfromastreambedelevatedbydebrisflowisthattheflowchannelcanbecleanedandthecross-sectionalareaincreased.(2)StonerevetmentwithconcreteliningWhensafetyismoreofaconcernduetorapidcurrenterosion,anditisdeemedbeneficialtoprotectthehabitats,aninnerconcreteliningisusedbehindthesurfacestonesinadditiontotheabovestonerevetment.Aconcreteliningprovidesastrongerresistancetoflooding.Althoughtheecologicalfunctionmaybesomewhatreducedduetotheconcretelining,thebackfillwithgravelbehindtheconcreteliningcandrainoffwaterintothestreambank.Thesurfacesofstonerevetmentstillhavenaturalappearanceandincrease\ntheroughnessofstreambank.ThisstrongermethodisoftennecessaryformanyrevetmentsinTaiwanduetotheextremerainfallsandfloodingduringsummer.(3)Streambankprotectionusingwood-logpilesThemethodcanberapidlyconstructedatlowcostandeasilyadaptstothesinuousgeographyofstreams.Itissuitableforslowcurrentstreamsorsectionofgentleslopes.Thecompletedrevetmentislow,anditiseasytocompletereforestationandbeautification.Thewoodpilesrotnaturallyandaredecomposedbymicroorganisms,thusbecomingmergedtotheenvironmentwithoutsacrificingtheirfunctions.Themethodcannotbeappliedtohigherosionpotentialorrapidcurrentsection.(4)Woodstakesandcoir-logrevetmentThemethodisappliedtocurrentvelocitylessthan3 m/s,andwhereurgent,temporary,andquicktreatmentsarerequired.Themethodadoptscoir-logforbackfillmaterials.Thefinishedrevetmenthasthecharacteristicsoflowerheightandpermeability.Thecoir-logrollsaremadefromplantfibersandwilldecomposeeventually.Similartowood-logpiles,woodstakesandcoir-logrevetmentwouldrotandbecomepartoftheenvironment.(5)BoxedgabionrevetmentThemethodisappliedtohigherosionpotentialandfastflowvelocitysections.Thecobblesandgravelsconfinedingabionsprovidebetterresistancethanstonerevetmentforflooding.Thepermeabilityishightoeasilydrainoffgroundwaterandrainfalls.Inaddition,whenthedeformationofrevetmentisnotuniformandexcessive,theflexibilityoftheboxedgabionscanprovidegoodcompatibilityforlargedeformation.Theporosityofthegabionsmakesitpossibleforfrogs,snails,andothercreaturestosurvivenexttostreams.(6)Arc-shapestonestreambedsillInperennialstreams,themethodcanbeadoptedtopreventthestreamfromerodingverticallyandhorizontally,tostabilizethestreambed,andtoreducevelocityofflow.Byapplyingthearchingeffect,themethodtransfersthepressureofrunningwatertothestreambank.Thereisonlycompressionpressurebetweenthestonesandnotension.Theconnectedandchainedconstructionismorestablethanasinglestone.Bythestonestreambedsills,thestreamwaterwilldescendtocreateadiversifiedwaterenvironmentsuchaspool,shoal,andslack,etc.Itwillincreaseindissolvedoxygenthusbenefittingaquaticanimals.(7)SlantstreambedsillThemethodcanreducethevelocityofflow,stabilizetheflow,preventstreambedfromscouring,andlettheflowcourseremainstable.Itadoptsconcreteandstonemattressinrapidflowsectiontoreducevelocityandregulatethegradientofstream.Italsoformsanaturallookingstonesurfacelandscape.5.InspectionoftheecologicalengineeringmethodsinTaiwanProperlydesignedecologicalengineeringmethodsareeffectiveforrestorationofecosystem.Duringplanninganddesignstagesofmitigations,thefactorssuchassafety,ecology,landscape,geomorphology,andhydrologywereconsideredbytheSWCB.Itwasfoundthattheecosystemsreinstategraduallyafterusingtheecologicalengineeringmethods.Throughthetwo-yearecologicalinvestigationsdirectedbySWCBforLiu-chungCreekinTainan,Mu-danCreekinTaipeiCounty,andTou-bain-kengCreekinTaichungCounty,withtheecologicalengineeringmethodsusinggentleslope,porousrevetmentsandreducingobstaclesinecologicalcorridors,thequantityofaquaticinsectsobviouslyincreased,andfishandshrimphavereturnedtothestreams.Inaddition,butterfliesandfirefliesliveinitafterthemitigations.Thisisthemostsolidbenefittotheecosystem.TheSWCBisproposingmoreecologicalinvestigationsforthoseareastreatedbytheecologicalengineeringmethodstostudytheeffectofthemethodstoenvironment.Theaverageannualrainfalloftheworldisabout500 mm.However,therainfallinTaiwanisfrom2500to\n3000 mmannually.DuringTyphoonMindulle(2July2004),withinonlythreedays,theabnormalhighrainfallwasmeasuredupto1159 mmincentralTaiwan,andupto2066 mminsouthernTaiwan,nearlytheaverageannualrainfallofTaiwan.On24August2004therecameTyphoonAere,whichcausedmanymitigationworksapplyingecologicalengineeringmethodstobedamaged.Therefore,itisobviousthattheecologicalengineeringmethodsimplementedinTaiwanshouldbelocalizedtocomplywiththeextremehighaverageannualrainfall.Strongerandsaferdesignswillbenecessary;thelocalizedecologicalengineeringmethodsdevelopedwillbesomewhatstrongerandsometimescanbeverydifferentfromthosedesignedinEurope,USA,andAustria([FISRWG,1998],[GrayandSotir,1996],[LiandEddleman,2002]and[Hsieh,2004]).AftertheChi-Chiearthquakein1999,theSWCBpaidmoreattentiontotheaspectofsafetyandecologyinmitigatingofstreams.Someprojects,constructedbyecologicalengineeringmethods,werestillsafeandstableduringthecalamityofheavyrainfallinTyphoonsMindulleandAere.Fieldreconnaissancedeterminedthatabouttenstreamsinwhichmitigationsusingecologicalengineeringmethodswerejustcomplete,survivedtheseverefloodingofTyphoonsMindulleandAere.Onlysomearc-shapestonestreambedsillswerelocallydamaged.AfterTyphoonsMindulleandAere,therewere821projects(atotalof390 ha)treatedwiththelandslidesourcecontrolwithstakingandwattlingmethodhadbeeninspected.Only164projectsshoweddamage(102slightdamageand62seriousdamage).Thedamageareaisabout58 ha.Therefore,theeffectivestabilizedareaismorethan85%.The15%damageareamostlyshowedlocalscouringorcollapsingcausedbythetremendousrainfalls.However,therewasnomajorhazardsuchasdebrisflowandlargescalelandslide.Thisalsoprovestheeffectivenessofthelandslidesourcecontrolmethod.differenteffectscanbeobservedforareaswithandwithoutthelandslidesourcecontroltreatment.Generally,landslideareasafterthetreatmentwillhaveafasterre-vegetationrateandbetterstability,thuscreatingmoreprotectedhabitatswithbiodiversity.6.IntegratedmitigationfordebrisflowTorrent—anexampleofHua-shanCreekinGu-kengCounty,TaiwanHua-shanCreekisnotaperennialstream.Waterflowonlyappearsduringheavyrainfallforacoupleofdays.Therefore,theaquaticlifeforminthecreekisveryrare.ThegeologicalconditioninthewatershedofHua-shanCreekisgenerallyunstablewithhighpotentialofdebrisflow.Themitigationforthecreekconsideredsafetyfirst,andecologysecond.Thedisastersofthedebrisflowsweretriggeredbyaheavyrainfalleventin2000andTyphoonTorajiin2001.Asaresult,thestreamchannelwaserodedinto50–60 mwide.Somesectionsofthestreamreachedahundredmeterswide.Thestreambedwasraisedup,rangingfromseveralmeterstomorethan20 m.Thesedimentsonthestreambedwerealsounstable.Frominvestigations,Hua-shanCreekshowsthecharacteristicsofdebrisflowtorrent,i.e.thesourcezone,transportationzone,anddepositionzone.TherearefewresidentsintheHua-shanCreekarea.Relocatingpeoplewillbethelong-termsafetysolutionbecausethereisnoomnipotentengineeringmethodthatcanensurethesafetyofpeoplelivinginadangeroushabitation.However,duetoimportantindigenousculturesandforruraldevelopment,theinhabitants,thegovernment,andSWCBconcurredtocommencetheintegrateddesignofthemitigationforHua-shanCreek.ThemajormitigationofHua-shanCreekispresentedasfollows([SWCB,2004],[Wu,2002a],[Wu,2002b],[Wu,2002c]and[Wu,2002d]):(1)Sourcezone:Fortreatmentoflandslidesourcezone,itisnecessarytoinvestigatethelocations,possibleslidingareasandvolumeofthelandslidefirst.Thelandslidesourcecontrolwithstakingandwattling\nmethodmentionedpreviouslywasadopted.(2)Sedimentationcontrol:Itisoftenfoundthatthestreambediserodedseriouslyinbothverticalandhorizontaldirectionsafterdebrisflowoccurrence.Asaresult,thestreambedcouldremainunstableandeasilyinducesliding.Itprovidesthesourceofsedimentswhichcanbetransportedtodownstreamandagainerodesthestreambed.Thescenariorepeatedfromupstreamtodownstreamperiodically.Forsedimentcontrol,seriesoflowcheckdamswereusedforapplyingecologicalengineeringmethods.Althoughtheselowdamsmaybeeasilyfilledup,theyraisedthestreambedwhichcanstabilizetoeofslopes.TheapplicationisdemonstratedintheupstreamoftheHua-shanCreek.(3)Transportationzone:Inthiszone,slitdamsandaseriesoflowcheckdamswereadoptedtoreducetheenergyofdebrisflowaswellaserosionofstreambed.ApplicationexampleisdemonstratedfortheNo.1andNo.2slitdams,stonedam,andaseriesoflowcheckdams.(4)Depositionzone:Inthiszone,theslitdamsandsedimentationbasinbasedontheecologicalengineeringmethodsweredesigned.Thevegetationwasappliedinthewide-openstreambed.Duetolimitationswhileacquiringtheland,alargesedimentationpondwasnotpossibleinthisproject.(5)Dredgingpathwayandeducationalarea:Thedebrisflowareaaftermitigationisplannedasaneducationalpark.Thesidewalkintheleftbankwasusedasrecreationalareaandforthestudyofecology.Thesidewalkwillalsobeusedasadredgingpathwayiffuturedebrisflowoccurs.Toquicklydrainrainfallwater,coarsegravelsarebuiltonthesidewalk.Also,stoneswereusedfortheguardrailsinsteadofconcrete.Togetherwiththehillslopevegetation,thedredgingpathwayprovidesacompromisebetweenleisurerecreationandengineering.(6)Debrisflowmonitoringstation:Adebrisflowmonitoringstationwasestablishedtomonitorthepossibledebrisflowandtoprovidethedataforresearchandeducation.(7)Cultureandlandscape:AfterfinishingthemitigationoftheHua-shanCreekareaforthedebrisflows,newbuildings,coffeeculture,andlocalartswillgraduallydevelop.TheareabecomesapopularrecreationalspotinTaiwan.Hua-shanCreekexperiencedTyphoonsMindulle(2July2004)andAere(24August2004)andsuccessfullywithstoodthesevereconsecutivetestsoffloods.Thesuccessisduetotheintegratedmitigationstrategybasedonecologicalengineeringmethods,includinglandslidesourcecontrolwithstakingandwattling,stonerevetment,stonestreambedsill,andtheconventionalslit/checkdamswithecologicalconsiderations.Themitigationgreatlyreducedthetransportationofsediments.Asaresult,thestormwaterflowisclearandthehillslopesbecomesuccessfullyvegetated.Thestreambedalsobecomesanaturalizedhabitatforfrogs,insects,butterflies,andbirds.Sufferingfromtheearthquakedisastersin1999anddebrisflowsin2000and2001,HuashanVillagewasseverelydamaged,becomingadesolatearea.Withlessonslearnedfromnature,thevillagehasbeenreconstructed/rehabilitatedandintegratedwithenvironmentfriendlymethodsfordisasterprevention,recreationinfrastructures,habitatimprovement,andforruralcommunitymanagement.Itisnowbecominganewrecreationattractionandthename“HometownofTaiwanCoffee”ofHuashanspreadsalloverthecountry.TheprosperityoftheHua-shanareaisagreatevidenceofsuccessfulimplementationoftheecologicalengineeringprinciples.7.Integratedmitigationforastream—anexampleofDing-zi-lan-kengCreekinTaipeiCountyDing-zi-lan-kengCreekwasplannedtoprotectitsoriginalpoolsandshoals,tocreatemoreriffles,torrents,turbulences,slacks,andbackwatersusingecologicalengineeringmethods,andtoenhancestreamfunctionsforvariousaquaticandterrestrialanimals.Sceneryrecreationalfunctionforhumanwasalsoconsidered.ThemajormitigationofDing-zi-lan-kengCreekisdescribedasfollows:\n(1)Theintegrateddesign:themitigationplanforDing-zi-lan-kengCreekisdividedintowatersourceprotectionarea,ecologicalprotectionarea,theecologicalexperienceareaandtherecreationareas(theQin-shuiBridge),mitigationarea(includingcheckdams,landslidesourcecontrols,andrevetments),historicalprotectionarea,scenerysuspensionbridge,pavilions,pedestrians,wetland,andvegetationbufferzones.(2)Thesedimentationmitigation:Ding-zi-lan-kengCreekshowscharacteristicsoflandslideandstreambankerosioninitsupstream.Toconsiderbothsafetyandhabitats,thestabilityofthestreambedisincreasedbytheecologicalengineeringmethods.(3)Theecologicalprotectionarea:Tomaintaintheoriginalfeaturesasmuchaspossibleandavoidinterferingwithamphibiousanimals,anyresidentialdevelopmentisforbidden.(4)Ecologicalbufferzones:Twobufferzonesaredesignedforlowerfrequencyofrecreationactivity.Theycontrolexcessinterferencetoamphibiousanimalsandthenearbyhabitats.(5)Vegetationbufferstripsandhabitatprotection:Vegetationbufferstripscanreducethetemperatureofwater,supplyfragmentsofplantstoimprovehabitatenvironment,decreasepollutantssuchassediments,toxicmattersandpesticide,etc.Thestripsalsoprovidefunctionsincludingfiltering,absorbing,purifying,andsupplyamphibiousanimalsagoodenvironmenttogrow.Artificialwetlandswereconstructedtopreventpollutionfromaccumulation.(6)Ecologicalexperienceandecologicalprotectionarea:Toletpeoplegetanecologicalexperiencewithoutinterferingintheecologytoomuch,low–densityandminimumstructureswereplanned.Theobservationroutesforaquaticanimalswerebuiltaccordingtothelocaltopographytominimizethequantityofcutsandfills.(7)Recreationarea:WashoutandlandslideoccurredatthedownstreamofDing-zi-lan-kengCreek.Itwasmitigatedwithstonerevetment,streambedsills,andarc-shapestonestreambedsillstocreatenaturalaquaticzonesandgentleslopingstreambanks.Ding-zi-lan-kengCreekisnotadebrisflowtorrent,thereforethestonesinthestreambedarenotenoughfortheecologicalengineeringmethods.Onlyabout30%ofthestonesusedarefromthecreek,andtheother70%werepurchasedfromanothersource.Therearevariousbio-environmentsinDing-zi-lan-kengCreekwhichisasignificantbiodiversityareaforaquaticanimals.Inordertoreducethesignificantchangeintheenvironment,originalfeaturesweremaintainedasmuchaspossiblewiththeecologicalengineeringmethodsformitigation.TheintegratedmitigationdesignhasexperiencedTyphoonAereandsurvivedfromflooding.8.ChallengeforpromotingecologicalengineeringmethodinTaiwan(1)Difficultyoflandacquisition:Morelandisusuallyrequiredforgeneralapproachesofecologicalengineeringmethodssuchasgentleslopeforstreambankprotection,sabodam,pool,andshoal,butitisdifficulttoacquireenoughlandinTaiwan.(2)Largenumberofhabitatstobeimproved:Conventionalengineeringworksuchasconcretedamsandconcreterevetmentsthatcouldimpacttheecologicalenvironmentneedstobeimproved.However,thenumberofthosefacilitiesissignificant.Howtosystematicallyperformhabitimprovementisachallenge.(3)Lackofnaturalresourcesanditscountermeasures:a.DuetotheuniquetopographyandrainfallintensitycharacteristicsinTaiwan,stone-pavedworkisoftenselectedforitsbetterdurabilityandstability.However,thelackofstonesandwoodlogsisacommonprobleminTaiwan.b.Thecountermeasuresshouldinclude:Establishstoragefacilitiesforstones;delimitspecificareastomineusablestones;importstonesorothernaturalmaterials;andencouragecivilianinvestmentindeveloping\nartificialstonesandwoodlogs.9.ConcludingRemarksDuetothehighaverageannualrainfallandspeciallandformsofTaiwan,thepromotionandapplicationoftheecologicalengineeringmethodsaremoredifficultthanothercountries.Itisbettertodeveloplocalizedecologicalengineeringmethodscomplyingwiththespecialgeological,hydrological,andenvironmentalconditionsofTaiwan.Forsoilandwaterconservationandsustainabledevelopment,weshoulddeemtheecologicalengineeringmethodsasageneralguidelineandapplymore“flexible”treatmentstogetherwithengineering,agronomic,andvegetationmeasures.Themitigationstrategyofthehazardsofstreamsandgulliesonhillslopesshouldbeanintegratedplanbytakingtheirwatershedsasaunitwithinvestigationsincludingecologicalresources,landslideanddebrisflowhazards,non-pointsourcepollution,andlocalculture.Itisalsoimportanttoinvolvetheparticipationoflocalresidents,experts,scholarstocomeupwithsuitableecologicalengineeringmethodsthatfitmostofthehabitatrequirements.Onlyenoughinvestigation,comprehensiveplanning,diligentconstruction,andmanagementinecologicalengineeringmethodscouldbuildthediversifiedhabitatsandcreateahigh-qualityenvironmentwithrespecttocompleteness,ecology,culture,andlocalcharacteristics.Therefore,humansandtheenvironmentcancoexistharmoniouslyandalsobiodiversityandsymbiosiscanbehighlighted.Startingfromtheintegrateddesignforwatershedandusingbothinnovativeandpracticaltechniques,wecanapplytheecologicalengineeringmethodsasthefoundationforhazardpreventionandmitigation.Alongwiththecontinualenhancementinecosystems,abetterlivingenvironmentcanbeachieved.AcknowledgementTheauthorsgratefullyacknowledgeMr.Zong-ruZuoforhisvaluableandconstructivecomments.\n台湾地区的水土保持生态工程方法武龙辉a，郑毅丰ba水土保持局，农委会，台湾南投市540号b水土保持系，国立中兴大学，台湾台中402号摘要:为了使减灾更有效，本文详细介绍了台湾局部生态工程方法的发展状况。为了加强水土保持和生态环境的保护，综合减灾规划是很必要的，包括安全、生态和景观的平衡，并将整个流域作为一个单元来处理。为了论证生态工程方法在台湾的推广成果，本文阐述了两个完整的用于山洪泥石流和河流的减灾案例。经过2004年的两次强台风后，大部分减灾工程都保留了下来，而且还很稳定（有一些轻微的损害）。这表明我们所研制的生态工程方法是非常适合减灾的，为了台湾的生态环境值得进一步推广。关键词：水土保持，生态工程方法；减灾；栖息地；侵蚀控制文章概要1、引言2、生态工程方法和栖息地2.1生态工程方法的功能2.2生态廊道的职能2.3常规工程的某些弊端3采用生态工程方法的河流减灾规划设计3.1基本概念3.2河流一体化设计的原则4台湾生态工程方法的精选案例5台湾地区生态工程方法的检验6山洪泥石流的综合减灾—以台湾顾铿县的华山河为例7河流的综合减灾—以台北县的丁子兰坑溪为例8在台湾推广生态工程方法的挑战9结束语致谢1.引言台湾水土保持的重要措施之一是生态工程方法。生态工程方法可以是生态保护和恢复的指标。台湾水土保持局（SWCB）2001年开始推动创新性的生态工程方法。由于生态工程的采用，防灾、生态保护与游憩已结合在一起。生态工程方法非常适合具有中等大小洪水潜力的地区。它可以用来调节河道，引导危险水流至河漫滩或滞洪池，减少急流的一些席卷力量。不可将该方法视为一个完整的防洪措施。由于山洪泥石流或非常急的河流，传统工程可能不可避免地要维持滑坡或泥石流脆弱地区的整体稳定，以及控制任何泥石流溢出。如果像滚水坝、拦砂坝这些传统结构更结实，出于环境友好的考虑，则应该尽可能多的建设这种结构。当不稳定的危险区受传统工程妥善保护时，更为灵活的生态工程方法可使其受冲刷/失败的风险减小；并且生态工程方法的功能发挥得更快，能够帮助环境和栖息地逐渐恢复。这就像是一个“生态疗法”在治疗曾经受损的环境。生态工程包括两个主要方法：开发新技术和应用新开发的生态工程方法。推动生态工程方法的任务包括生态工程方法参考图纸\n的发展、生态调查、栖息地改善、生态指标的建立、滑坡地区的植物措施的发展和关于生态工程方法的一系列会议。创建生态工程方法是为了适应国内的生物和环境条件。生态工程方法的优点在于强调水土保持各方面的综合考虑。本文表明生态工程可适当地应用到流域减灾、保护和生态恢复。此外，娱乐基础设施、农村社区和农业经济可以同时发展。2．生态工程方法和栖息地2.1生态工程方法的功能（1）改善生态系统还原能力（如滑坡、泥石流等大规模灾害）：如果该工程设计中提供自然环境、生态系统以及相应周边特性的还原能力，生态工程方法适于大规模自然灾害的减灾。（2）改进生态系统的保护能力（如河堤、河床冲刷类的中型规模灾害）：该方法应考虑多孔材料，可形成许多空隙，以便为水生和陆生动物提供屏障和保护。减灾应考虑流域总体特征，维护原自然河流环境的关系，避免改变当前生态系统或单用途的结构。（3）改善生态系统的可恢复性（如面蚀这样的小规模灾害）：原来的当地材料如当地的石头、树林和植物应采取减灾措施，并且这种措施应该有能力提高生态系统的可恢复性。（4）改善河流功能（河流可用来减灾）：河流减灾和复原设计应考虑纳入当地环境、娱乐和未来住宅建筑相容的潜在目的。纳入生态工程方法，如建筑游憩区、景观河堤和生态缓冲区，河流的减灾功能可得到改善。2.2生态廊道的职能创造一个生态廊道的目标是为了保留或重建当地动物生存、繁殖、觅食和移民需要的主要途径。生态廊道的角色包括管道、栖息地、过滤、阻隔、源和汇（诺斯，1991）。下面讨论一些台湾生态走廊的例子。（1）纵向生态廊道的改善2003年，在台南县柳忠河的上游建造了一个纵向生态廊道（鱼通道）和一个拦沙坝。在施工前、施工中和施工后对鱼的种类进行了普查。施工前的调查显示上游存在的鱼较少，原因在于河道中1.3m高的坎阻止了上游鱼米的迁移。走廊与鱼类通道建成后，上游鱼的数量在适当增加。此外，鱼类表现得更加活跃。这可能是因为游泳空间得以扩大和近亲繁殖的可能性被降到最低。建立鱼类通道之后，发现了了更多的鱼类，并且他们的活动明显增加。（2）纵向廊道的施工后番子坑溪位于北台湾的台北县，这里富有不同的物种。2001年7月，纳莉台风引起了河堤的崩溃和侵蚀，改变了其航道，并造成了严重的泥沙淤积。河流栖息地被破坏，许多水生动物的生存受到威胁。为了振兴生态，使用基于非水泥的生态工程方法，包括用来护岸的木桩支护和纵向廊道的弧形石质河床边坎。我们也希望重建河流的自然风光。为了提供一个适宜的栖息地，设计了蜿蜒的河流，以创造出各种水环境，如泳池、沙洲、浅滩、回水、漏水。基于施工前后调查的比较，鱼和虾已经回到了河流并且数量大增。因为无障碍的弧形河床边坎和漏水帮助鱼类在上游和下游之间迁移。（3）横向廊道改造利用缓坡在台北县归崇村的泥石流减灾中，将坡度平缓的护岸工程设计得适应地形平坦的地方。缓坡的角色是确保水生和陆地动物横向廊道连续性的互动基地。（4）以缺乏缓坡造成的缺陷为例针对台北县大津坑溪泥石流的河堤减灾设计为边坡1:1的滚水坝，没有特定的缓坡。当鹿进入河流觅食、掉进比河堤还低3米的渠道时，它自己是爬不上来的。出于恐惧，鹿大叫进而冲下河流。人类费了九牛二虎之力才将鹿营救。这就教给我们有一个缓坡带和生态廊道的重要性。2.3常规工程中某些弊端\n天然河堤允许渗水。地下有机质和矿物质随着地下水进入河流而输送。天然多孔材料促进水交换，从而维持水质。用来预防洪水和侵蚀的混凝土被认为比自然河流更安全。但是，它会破坏地下水的连续性。另外，一些具有光滑的垂直混凝土护岸和通道的河流也在兴建。这样的设计会造成种植、鱼类洄游、两栖爬行动物互通等方面的困难。高大的滚水坝将切断纵向生态走廊。对于一个常年流，滚水坝将阻碍鱼类洄游，这时考虑建立鱼道。落差高于1米的拦砂坝可能也会阻碍鱼类洄游。对于流量调节工程，混凝土河床将会使池塘、滩涂和浅滩消失，水质退化。3．采用生态工程方法为河流减灾的规划设计3.1基本概念（1）考虑安全、生态和景观的平衡根据区域特点，考虑安全、生态与景观的优先次序和平衡。对于市区附近的小山坡来说，安全应当是第一位的。与此相反，对于由各种生态系统组成的大山坡来说，生态应该是主要因素。对于其他地区来说，安全、生态和景观均应适当考虑。（2）根据当地环境制定合适的减灾方法做出与当地环境兼容的综合设计，包括区域生态资源、自然灾害、环境特点、山水风光、历史古迹和居民观念等的兼容。（3）完成流域的综合规划设计把流域作为一个整体单元来做减灾和复原计划，包括集水区、自然生态区、环境保护区、栖息地改善区和游憩区等（4）建立水环境建设水生态环境设施，如池塘、沙洲、浅滩、回水、漏水、导流、鱼道和人工湿地等。建立巨石型护岸和重新安排河床现有岩石是个控制流速和创建上述水环境的好方法。（5）建立陆地环境建设陆地生态环境设施，如植被、花园和露台。3.2河流一体化设计的原则（1）建立一个自然生态环境提供有利于池塘、沙洲、激流、浅滩、漏水、回水和洪水地形自然形成的接近自然的工程。（2）根据地貌设计滞洪池在河流减灾中，我们可以把一些开放的领域用作滞洪池，如洪水地形、游乐场、湿地、农业池塘、梯田等。（3）遵守河流的原始河道对于河堤的减灾和避免等宽或并行通道的设计来说，遵守河流的原始河道是非常重要的。（4）避免干扰栖息地为了更好地保护栖息地，应该规划远离生态敏感点、远离可能受影响地区的必要建设。（5）设计河堤缓坡为了给水生和陆地动物之间的互通提供生态廊道，提议设计边坡比小于1：1.5（V：H）的河堤缓坡。（6）在河道和河堤堆放石头以产生气孔和空隙石头间的空隙为动物提供了庇护所和栖息地。使水生动物找到住所、草料、休息、睡眠和繁殖的地方，而混凝土结构的栖息地通过加入石材表面可以得到改善。（7）遵守以下五个原则，以有效减少对环境的建设影响a在结构面使用多孔材料,以制造提升栖息地的粗糙度和空隙。b降低坝高，尽量减小建设规模。c建造平缓的河堤边坡，以创建生态廊道。d施工中使用天然材料，以追求多样性。e创造建筑间的界面和利于水循环的渗透性地面。\n4．台湾地区生态工程方法的精选案例台湾地区生态工程方法的精选案例介绍如下：（1）石头护岸石头护岸的主要目的是保护河道的底部免受侵蚀尤其是它可以防止渗漏造成的管涌。构建良好的石板护岸可被认为是能够承受河堤主动土压力的挡土墙。石头和成品的表面有一种天然外观。石头之间的间隙、孔洞比混凝土护坡能够提供更好的栖息地和更好的植被。最好的石头是之前被冲下河流或泥石流中的石头，因此要节省金钱和时间转移其他地方的石头。使用被泥石流搬迁到河床的石头的另一个好处在于泥石流流道可清洗，且其截面积增加。（2）混凝土衬砌的石头护岸由于目前更加快速的侵蚀，使得安全备受关注、被认为利于保护栖息地时，除上述石头护岸外，在表层石头背后的内层采用混凝土衬砌。混凝土衬砌对洪水有着更强的抵抗力。虽然因混凝土衬砌生态功能可能会有所减少，但混凝土衬砌之后的碎石回填可以将水流导排至河堤。石头护坡的表面仍然有自然外观，而且增加了河堤粗糙度。由于夏季的极端降雨和洪水，台湾的许多护岸工程都需要这种更强有力的方法，（3）使用木桩的护岸工程该方法可以以很低的成本快速建造，并且容易适应河流的蜿蜒地形。这适于当前的慢流或缓坡部分。已完成的护岸较低，易完成重新造林和美化。木桩自然腐烂且被微生物分解，从而成为不牺牲其功能的环境。该方法不能用于高潜在侵蚀力或激流的部位。（4）木柱和椰壳桩护岸该方法适用于当前流速小于3米/秒，且需要紧急、临时、快速治理的地段。该方法采用椰壳桩作为回填材料。已完工护岸具有较低高度和渗透性的特点。椰壳桩辊由植物纤维做成，最终会分解。类似于木桩，木柱和椰壳桩护岸会腐烂，并成为环境的一部分。（5）箱装石笼护岸该方法适用于高侵蚀潜力和流速急的部位。卵石和砾石局限于石笼对洪水比石头护岸有着更强的抵抗力。它的透气性较高，很容易排出地下水和降雨。此外，当护岸形变不均匀且过度时，箱装石笼的灵活性可以更好地适应较大变形。石笼孔隙使青蛙、蜗牛和其他生物在河流附近生存。（6）弧形石头河床的基底对于常年流，该方法可以用来防止河流的下切和水平侵蚀、稳固河床以及减少流速。该方法通过应用拱原理，将水流压力转移到河堤上。只有石块之间的压缩力而没有张力。连接的链式建筑比一块石头更稳定。沿着石头河床基底，河水将会下降并创造出一个多元化的水环境，如池塘、浅滩和漏水等，这将增加溶解氧含量，使水生动物受惠）。（7）倾斜河床的基底该方法可降低流速、稳定流量、防止河床冲刷，使流道保持稳定。在激流部位采用混凝土和石头床垫，以减少流速和调节流速梯度；也形成了一道石材表面的自然景观。5．台湾生态工程方法的检验适当设计的生态工程方法对生态系统恢复是有效的。在减灾阶段的规划设计期间，水土保持局考虑了安全、生态、景观、地貌和水文等因素。结果发现，使用生态工程方法后的生态系统在逐步恢复。通过水土保持局领导的对台南县Liu-chungCreek、台北县Mu-danCreek和台中县Tou-bain-kengCreek为期两年的生态调查（2003年）显示，采用缓坡、多孔、护岸和减少生态廊道障碍的生态工程方法后，水生昆虫数量明显增加，鱼虾重新回到河流。此外，减灾后蝴蝶和萤火虫住在里面。这对生态效益来说，是最坚实、最有益的。水土保持局正在提议对生态工程方法处理过的区域进行生态调查，以研究该方法对环境的影响。。\n世界的平均年降雨量约500毫米。然而，台湾降雨是从每年2500至3000毫米。在台风蒲公英（2004年7月2日）登陆的短短三天内，异常高的降雨量使台湾中部的测量值为1159毫米，在台湾南部多达2066毫米，接近台湾的年平均降雨量。2004年8月24日，艾利台风来了，使得不少采用生态工程方法的减灾工程受到损害。因此，很明显，台湾实施的生态工程方法应该本地化，以符合极高的年平均降雨量。更结实、更安全的设计是必要的；本地化的生态工程方法的发展将会有所加强，有时可以与欧洲、美国和奥地利设计的那些大不相同。([FISRWG,1998],[GrayandSotir,1996],[LiandEddleman,2002]and[Hsieh,2004])。在1999年的集集大地震后，水土保持局更注重河流减灾的安全与生态方面。有些通过生态工程方法构建的工程，在台风蒲公英和艾利带来的暴雨灾害期间，仍然安全、稳定。现场勘察认定，约有10条刚采用生态工程方法完成减灾的河流，在蒲公英和艾利台风带来的严重水灾中幸存下来。只有一些弧形的石头河床有局部损坏。蒲公英和艾利台风后，有821个采用放样和wattling方法进行滑坡源控制的工程(总计390公顷）受到了检验。只有164个工程受到损坏（102个是轻微损坏和62个是严重损坏）。破坏面积约58公顷。因此，有效的稳定面积超过85％。15％损坏面积主要表现在局部冲刷或暴雨造成的倒塌。但是没有大的灾害，如泥石流、大规模滑坡。这也证明了滑坡源控制方法的有效性。可以观察到有无滑坡源控制区域的不同的效果。一般来说，采取措施后的滑坡地区将有更快的植被恢复率和较好的稳定性，从而创造出具有生物多样性的、更具保护性的栖息地。6．泥石流急流的综合减灾——以台湾顾铿县的华山河为例华山河非常年流。水流只出现在两天的强降雨期间。因此，该河流的水生生物非常罕见。因泥石流发生潜在性很高，华山河流域的地质条件很不稳定。河流减灾应考虑安全第一，生态第二。泥石流灾害是由2000年的大暴雨和2001年的桃芝台风触发的。结果，河道宽被侵蚀成50-60米，流部分路段达到了百米宽。河床抬升，由数米变成大于20米。河床的沉积物也极不稳定。调查显示华山河表现出泥石流急流的特点，即源区、运输区和沉积区。在华山河地区有少数居民。搬迁人民是保证人民长期安全的办法，因为没有万能的工程方法可以确保生活在危险居住区的人民的安全。但由于重要的土著文化和农村发展，居民、政府和水土保持局开始了对华山河减灾的一体化设计。华山河的主要减灾介绍如下（[水土保持局，2004]，[吴，2002a]，[吴，2002年b]，[吴，2002年c]和[吴，2002d]）：（1）源区：治理滑坡源区首先进行当地、可能滑动区和滑坡体的调查是必要的。前面提到的采用放样法和wattling法进行滑坡源控制被采纳。（2）沉积控制：人们常常发现，泥石流发生后，河床的垂直和水平方向均被侵蚀得非常严重。因此，河床变得不稳定，容易诱发滑动。它提供了可输送到下游的泥沙源，并再次侵蚀了河床。该场景从上游到下游多次周期性循环。对于泥沙控制，一系列的低拦砂坝应用了生态工程方法。虽然这些低拦砂坝很容易被填满，但它们抬高了河床，可以稳定河床坡脚。这一原理在华山河上游应用。（3）运输区：在这个区域，滚水坝和一系列的低拦砂坝，通过了检查，以减少泥石流的势力以及河床侵蚀。1号和2号滚水坝、石坝和一系列低拦砂坝的应用实例.（4）沉积区：在这个区域，设计了基于生态工程方法的滚水坝和沉积池。宽敞的河床应用了植被措施。由于获取土地的限制，在这个工程中修建大型沉淀池是不可能。（5）疏浚途径和教育领域：计划将减灾后的泥石流区作为教育园区。左岸的人行道用作休闲区和生态研究区。如果以后再发生泥石流，人行道也将被用作疏浚途径。为了尽快排出降水，应在人行道上铺设粗砾石。另外，石头被用做护栏而不是混凝土。与坡面植被一起，疏浚途径提供了一个休闲娱乐和工程之间的兼容。\n（6）泥石流监测站：建立泥石流观测站是为了监测可能发生的泥石流，并为研究和教育提供数据。（7）文化和山水：完成华山河的泥石流减灾后，新建筑、咖啡文化和民间艺术将逐步发展。该地区将变成台湾很受欢迎的一个娱乐场所。华山河经历了蒲公英台风（2004年7月2日）和艾利台风（2004年8月24日），并成功地经受了严重洪水的连续考验。成功的原因是基于生态工程方法的综合减灾战略，包括用放样和wattling方法的滑坡源头控制、石头护坡、、石头河床基底和与生态结合的传统滚水坝、拦砂坝。减灾大大降低了沉积物运输。结果是雨水变得清澈，山坡变得长满植被。河床也成为青蛙、昆虫、蝴蝶和鸟类的天然栖息地。经过1999年的地震和2001年的泥石流灾害后，华山村遭到严重破坏，变成一个荒凉的地方。从自然中汲取的教训看，该村已被重建/修复,并与灾害预防、娱乐设施建设、人居环境改善和农村社区管理等环境友好方法相结合。它正在成为一个新的休闲景点，且名为华山的“台湾咖啡之乡”遍及全国各地。华山地区的繁荣是生态工程原理成功实施的一大证据。7．河流的综合减灾——以台北县的丁子兰坑溪为例丁子兰坑溪计划保护其原有的池塘和沙洲，以用生态工程方法创造更多的浅滩、激流、湍流、漏水和回水，并为各种水生和陆地动物强化溪流的功能。同时也考虑了人类的风景游憩功能。丁子兰坑溪的主要减灾效应描述如下：（1）综合设计：丁子兰坑溪减灾计划被分为水源保护区、生态保护区、生态体验区和娱乐区（秦水桥）、减灾地区（包括拦砂坝、滑坡源控制和护岸）、历史保护区，风景吊桥、凉亭、人行道、湿地和植被缓冲带。（2）沉淀减灾：丁子兰坑溪显示出滑坡的特点，并在其上游溪流出现河堤侵蚀。从安全性和生境看，生态工程方法使河床的稳定性增强。（3）生态保护区：为了尽可能多的保持原有特征，避免对两栖动物的干扰，严禁任何居住发展。（4）生态缓冲区：为了降低休闲活动的频率，共设计两个缓冲区。他们可控制对两栖动物和附近生境产生的过量干扰。（5）植被缓冲带和栖息地保护：植被缓冲带可降低水温和植物碎片供应，以改善人居环境和降低如沉淀物、有毒物质和农药等的污染物。还提供包括过滤、吸收、净化和为两栖动物提供良好生长环境的功能。还建造了人工湿地，以防止累积污染。（6）生态体验和生态保护区：为了让人们获得没有太多生态干扰的生态体验，设计了低密度的、最小化的结构。根据当地地形尽量减少削割和填补数量，修建水生动物的观赏路线。（7）娱乐区：水毁、滑坡发生时的丁子兰坑溪的下游。这是用石头护坡、河床基底和圆弧形石头河床基底来创造自然水生区和缓坡河堤来减灾。丁子兰坑溪不属于泥石流急流，因此河床中石头不足以生态工程方法之用。所用的石头仅30％来自河床，另外70％从其他源地购买。在丁子兰坑溪有各种各样的生物环境，对水生动物来说是一个重要的多样生物多元化区域。为了减少环境中的重大变化，用生态工程方法减灾要尽量保持原有特点。该综合减灾设计经历了台风艾利并从洪水中幸存。8．推动台湾生态工程方法的挑战（1）土地收购的难度：生态工程方法的一般途径通常需要较多的土地，如护岸工程、防砂坝、池塘和沙洲需要坡度平缓，但在台湾很难获得足够的土地。（2）改善大量栖息地：像混凝土坝和混凝土护岸这样的传统工程，可能影响生态环境的需要并使其得到改善。然而，这些设施的数量非常重要。如何系统地施行栖息地改善成为一个挑战。\n（3）自然资源缺乏及其对策：a.由于台湾独特的地形和降雨强度，石铺作业往往是更好的选择，因为它更好的耐用性和稳定性。然而，石头和木材的缺乏是台湾的常见问题。b.对策应包括：建立石质储存设施；划定开采可用石块的特定区域；进口石块或其他天然材料；人造石和原木的发展鼓励民间投资。9．结束语由于台湾较高的年平均降雨量和特殊地貌，生态工程方法的推广和应用比其他国家更困难。遵守台湾的特殊地质、水文和环境条件，开发本地化的生态工程方法更好。为了水土保持和可持续发展，我们应该将生态工程方法视为一般指引，并将更“灵活”的处理与工程、农艺和植被措施应用在一起。山坡上沟谷灾害和河流灾害的减轻战略，将流域和包括生态资源、山体滑坡和泥石流灾害、非点源污染和当地文化的调查视为一个整体，应该是一个综合的计划。同样重要的是，让当地居民、专家和学者参与，想出适当的生态工程方法，以适应大多数人的需求。只有足够的调查、全面规划、勤政建设和生态工程方法的管理可以建立多样化的生境，创造一个尊重完整性、生态、文化、和地方特色的高品质的环境。因此，人类与环境可以和谐共存，同时生物多样性和共生可以得到突出。起源于流域综合设计和创新、实用技术的应用，我们可以将生态工程方法作为预防和减轻灾害的基础。随着生态系统的持续提升，可得到更好的生活环境。致谢笔者非常感谢宗茹佐先生宝贵的、建设性的意见