Dynamic adaptive policy pathways : A method for crafting robust decisions for a deeply uncertain world

Delft University of Technology

Dynamic adaptive policy pathways : A method for crafting robust decisions for a deeply

uncertain world

Haasnoot, M; Kwakkel, JH; Walker, WE; Maat, J

DOI

10.1016/j.gloenvcha.2012.12.006

Publication date

2013

Document Version

Final published version

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Global Environmental Change

Citation (APA)

Haasnoot, M., Kwakkel, JH., Walker, WE., & Maat, J. (2013). Dynamic adaptive policy pathways : A method

for crafting robust decisions for a deeply uncertain world. Global Environmental Change, 23(2), 485-498.

https://doi.org/10.1016/j.gloenvcha.2012.12.006

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Dynamic

adaptive

policy

pathways:

A

method

for

crafting

robust

decisions

for

a

deeply

uncertain

world

Marjolijn

Haasnoot

*

,

Jan

H.

Kwakkel

,

Warren

E.

Walker

,

Judith

ter

Maat

a_{UtrechtUniversity,DepartmentofGeosciences,P.O.Box80115,3508TCUtrecht,TheNetherlands} b

TwenteUniversity,DepartmentofWaterEngineering&Management,P.O.Box217,7500AEEnschede,TheNetherlands c

DelftUniversityofTechnology,FacultyofTechnology,PolicyandManagement,P.O.Box5015,2600GADelft,TheNetherlands d

Deltares,P.O.Box177,2600MHDelft,TheNetherlands

1. Introduction

Nowadays, decisionmakers face deep uncertainties about a myriad of external factors, such as climate change, population growth, new technologies, economic developments, and their impacts.Moreover, notonlyenvironmental conditions,but also societal perspectives and preferences may change over time, including stakeholders’ interests and their evaluation of plans (Offermans, 2010; van der Brugge et al., 2005). Traditionally, decisionmakersinmanypolicydomains,includingwater manage-ment,assumethat thefuturecan bepredicted.Theydevelop a static‘optimal’planusingasingle‘mostlikely’future(oftenbased ontheextrapolationoftrends)orastatic‘robust’planthatwill produce acceptable outcomes in most plausible future worlds

(Dessai and Hulme, 2007; Dessai and Van der Sluijs, 2007;

Hallegatteet al., 2012). However, if thefuture turns out to be

differentfromthehypothesizedfuture(s),theplanislikelytofail.

McInerney et al. (2012)liken this to‘‘dancing on thetop of a needle’’.But,asthefutureunfoldspolicymakerslearnandusually respondtothenewsituationbyadaptingtheirplans(adhoc)tothe new reality. Adaptation over the course of time is not only determinedbywhatisknownoranticipatedatpresent,butalsoby whatisexperiencedandlearnedasthefutureunfolds(Yohe,1990) andbythepolicyresponsestoevents(Haasnootetal.,2012).Thus, policymaking becomes part of the storyline, and thereby an essentialcomponentofthetotaluncertainty–infact,Hallegatte etal.(2012)includetheadaptationofdecisionsovertimeinan updateddefinitionof‘deepuncertainty’.

Toaddressthesedeepuncertainties,anewplanningparadigm has emerged. This paradigm holds that, in light of the deep uncertainties, one needs to design dynamic adaptive plans (Albrechts,2004;deNeufvilleandOdoni,2003;Haasnootetal., 2011;Hallegatte,2009;Hallegatteetal.,2012;Rangeretal.,2010; SchwartzandTrigeorgis,2004;Swansonetal.,2010).Suchplans contain a strategic vision of the future, commit to short-term actions, and establish a framework to guide future actions (Albrechts,2004;Rangeretal.,2010).Theseedsforthisplanning paradigmwereplantedalmostacenturyago.Dewey(1927)argued ARTICLE INFO

Articlehistory: Received15June2012

Receivedinrevisedform3December2012 Accepted18December2012 Keywords: Uncertainty Policymaking Adaptationpathways Adaptivepolicies Watermanagement Rhinedelta ABSTRACT

Anew paradigmforplanningunderconditionsofdeepuncertainty hasemergedin theliterature. Accordingtothisparadigm,aplannershouldcreateastrategicvisionofthefuture,committoshort-term actions,andestablishaframeworktoguidefutureactions.Aplanthatembodiestheseideasallowsforits dynamic adaptation over time to meet changing circumstances. We propose a method for decisionmaking under uncertain global and regional changes called ‘Dynamic Adaptive Policy Pathways’.Webaseourapproachontwocomplementaryapproachesfordesigningadaptiveplans: ‘AdaptivePolicymaking’and‘AdaptationPathways’.AdaptivePolicymakingisatheoreticalapproach describingaplanningprocesswithdifferenttypesofactions(e.g.‘mitigatingactions’and ‘hedging actions’)andsignpoststo monitorto seeifadaptationisneeded.In contrast,AdaptationPathways provides an analytical approachfor exploring and sequencing a set ofpossible actions based on alternativeexternaldevelopmentsovertime.We illustratetheDynamicAdaptivePolicyPathways approachbyproducinganadaptiveplanforlong-termwatermanagementoftheRhineDeltainthe Netherlandsthattakesintoaccountthedeepuncertaintiesaboutthefuturearisingfromsocial,political, technological,economic,andclimatechanges.Theresultssuggestthatitisworthwhiletofurthertest andusetheapproach.

ß2012ElsevierLtd.

*Corresponding author at: Deltares, P.O. Box 177, 2600 MH Delft, The Netherlands.Tel.:+31883358175.

E-mailaddresses:Marjolijn.Haasnoot@deltares.nl(M.Haasnoot), J.H.Kwakkel@tudelft.nl(J.H.Kwakkel),W.E.Walker@tudelft.nl (W.E.Walker),Judith.TerMaat@deltares.nl(J.terMaat).

ContentslistsavailableatSciVerseScienceDirect

Global

Environmental

Change

j ou rna l hom e pa ge : w w w. e l s e v i e r. c om/ l o ca t e / gl oe n v cha

0959-3780ß2012ElsevierLtd.

http://dx.doi.org/10.1016/j.gloenvcha.2012.12.006

Open access under CC BY-NC-ND license.

thatpolicies shouldbe treatedasexperiments,with the aimof promoting continual learning and adaptation in response to experienceovertime.Earlyapplicationsofadaptiveplanscanbe foundinthefieldofenvironmentalmanagement(Holling,1978;Lee, 1993;McLainandLee,1996),andinvolvetheabilitytochangeplans basedonnewexperience andinsights (Pahl-Wostletal.,2007).

Collingridge(1980)arguesthat,givenignoranceaboutthepossible sideeffectsoftechnologiesunderdevelopment,oneshouldstrivefor correctability of decisions, extensive monitoring of effects, and flexibility.Rosenhead(1990)andRosenheadetal.(1972)presented flexibility,in terms of keepingoptions open,as an indicator to evaluatetherobustnessofstrategiesunderuncertainty.

This planning paradigm, in one form or another, has been receivingincreasingattentioninvariouspolicydomains.Dynamic adaptiveplansarebeingdevelopedforwatermanagementofNew York(Rosenzweiget al.,2011;YoheandLeichenko,2010),New Zealand(LawrenceandManning,2012),andtheRhineDelta(Delta Programme,2011,2012;JeukenandReeder,2011;Roosjenetal., 2012), and havebeendeveloped fortheThamesEstuary(Lowe etal.,2009;McGaheyandSayers,2008;ReederandRanger,online; Sayersetal.,2012;WilbyandKeenan,2012).Suchapplicationsare also arising in other fields (see Swanson and Bhadwal, 2009; Walkeretal.,2010forexamples).

Alarge numberofapproachesandcomputationaltechniques existtosupportdecisionmakingunderdeepuncertainty(seee.g.

DessaiandVanderSluijs,2007;Hallegatteetal.,2012;IISD,2006; Metzetal.,2001;Swansonetal.,2010;Walkeretal.,acceptedfor an overview of a strand of approaches). With respect to approaches,theThames2100projectuseddecisiontreestoanalyze sequentialdecisionsforpreparingtheThamesEstuaryforfuture sealevelrise.IntheNetherlands,RealOptionsAnalysishasbeen usedtoassess optimalcostsand benefitsof pathwaysforfresh watersupplyoftheSouthwesternDelta(vanRhee,2011)andfor studyinghowflexibilitycanbebuiltintofloodriskinfrastructure (Gersonius et al., 2013). To show dependencies of choices for shipping, a decision tree has been used in the Dutch Delta Programme(DeltaProgramme,2011).Roadmapshavebeenused toillustrateasequenceofactionsinwatermanagementstudies (e.g.forthelakesIJsselmeer(unpublished)andVolkerak

Zoomm-eer (Projectteam Verkenning oplossingsrichtingen

Volkerak-Zoommeer,2003). TheBackcasting approachaimsat describing

adesirablefuture,andthenlookingbackwardsfromthatfutureto thepresenttodevelopapathwayofactionsneededtorealizethis future (Ho¨jer and Mattsson, 2000; Lovins, 1976; Quist and

Vergragt, 2006). Assumption-Based Planning begins with an

existingplanand analyzes thecritical assumptions inthis plan (Dewaret al., 1993). Ituses signposts tomonitor theneed for changes.RobustDecisionMakingisanapproachthatusesmany computationalexperiments tocreate an ensemble of scenarios againstwhichcandidateactionsareevaluatedinordertodevelop robustactions(GrovesandLempert,2007;Lempertetal.,2006). Severalplanningapproachesconsiderreassessmentandtheability to change policies based on new insights in a planning circle (LoucksandVanBeek,2005;Pahl-Wostl,2007;Rangeretal.,2010; Swansonetal.,2010;WillowsandConnell,2003).ThePanelon

America’sClimateChoices(2010)referstothis as‘iterativerisk management’ that ‘is a system for assessing risks, identifying optionsthat are robust acrossa range of possiblefutures, and assessingandrevisingthosechoicesasnewinformationemerges.’ Among the computational techniques are Scenario Discovery (BryantandLempert,2010;LempertandGroves,2010), Explor-atoryModelingandAnalysis(Bankes,1993;Bankesetal.,2013), andInfo-Gapdecision theory(Hall andHarvey,2009;Korteling etal.,2012).

These approaches and computational techniques, although developedfor differentpurposes,have beenfoundvaluable for

designing adaptive policies (Bankes, 2002; Hall et al., 2012; Hallegatteetal.,2012;Hamaratetal.,2012;Lempertetal.,2000, 2002).Theydifferintermsoftheconceptsemployed,andprovide differentkinds decision supportinformation(Hall et al.,2012). Consequently,theyhavedifferentstrengthsandlimitations.This situationcallsforresearchintocomparingthevariousapproaches and techniques, providing an understanding of their relative strengths and weaknesses, and identifyingthe contexts within whicheachoftheapproachesandtechniquesis most appropri-atelyemployed(Halletal.,2012;Hallegatteetal.,2012;Ranger etal.,2010).Inaddition,wearguethatitisworthwhiletoassess theextenttowhichthedifferentterminologiesusedsignifyreal differencesintheunderlyingconcepts,forthiscancontributeto harmonizingthefield.

In this article, we analyze two existing adaptive planning approaches andshowhowtheemployed conceptsare partially overlappingandpartiallycomplementary,resultinginan integra-tion of the two approaches. We look at Adaptive Policymaking

(Kwakkel et al., 2010a; Walker et al., 2001) and Adaptation

Pathways(Haasnootetal.,2012).AdaptivePolicymakingprovides astepwiseapproachfordevelopingabasicplan,andcontingency planningtoadapt thebasicplantonewinformationovertime. Adaptation Pathways provide insight into the sequencing of actionsovertime,potentiallock-ins,andpathdependencies.An exampleofafamilyresemblancebetweenconceptsusedbythese two approaches is the concept of an adaptation tipping point (Kwadijketal.,2010)usedinAdaptationPathwaysandthenotion of a trigger fromAdaptive Policymaking. Anadaptation tipping pointisthepointatwhichaparticularactionisnolongeradequate for meeting the plan’s objectives. A new action is therefore necessary.Atriggerspecifiestheconditionsunderwhicha pre-specifiedactiontochangetheplanistobetaken.

Afundamentalchallengeinplanningresearchistheassessment oftheefficacyofnewplanningmethodsandconcepts.Theproblem ispointedlysummarizedbyDewaretal.(1993,p.58)‘‘nothingdone intheshorttermcan‘prove’theefficacyofaplanningmethodology, norcanthemonitoring,overtime,ofasingleinstance ofa plan generatedbythatmethodology,unlessthereisacompetingparallel plan’’.Withrespecttohowaplanningconceptistested,theplanning research literature tends to look toward controlled real world application(Dewaretal.,1993;Hansmanetal.,2006;Straatemeier etal.,2010).However,analogoustootherdesignsciences(Freyand Dym,2006),theevaluationofaplanningconceptcanalsoutilize othersourcesofevidence(KwakkelandVanDerPas,2011;Kwakkel etal.,2012).Evidencecancomefromplanningpractice,fromvirtual worldsthatrepresenttheworldofpracticebutarenottheworldof practice(Scho¨n,1983),andfromtheoreticalconsiderations.Inthis paper,toassesstheefficacyoftheoutlinedintegrationofAdaptive PolicymakingandAdaptationPathways,weusesuchavirtualworld intheformofapplyingthepresentedplanningconceptstoareal world decision problem currently faced by the Dutch National Government. This application serves to illustrate the concept, describeshowitcouldbeusedtodevelopadynamicadaptiveplan, andoffersafirstsourceofevidenceofitsefficacythroughacritical reflectionontheapplication.

Thepaperultimately proposes amethodfor decisionmaking underdeepuncertaintycalledDynamicAdaptivePolicyPathways, whichisacombinationofAdaptivePolicymakingandAdaptation Pathways. We first provide short introductions to each of the underlyingapproaches,andthenexplorehowthetwoapproaches can be integrated into a single approach based on the strong elements of both to produce a dynamic adaptive plan. We demonstratetheapproachbyproducingadynamicadaptiveplan forwatermanagementoftheRhineDeltaregionoftheNetherlands that takes into account the deep uncertainties associated with globalclimatechange.

2. Thetwounderlyingapproaches

2.1. AdaptationPathways

TheAdaptationPathways approachis summarizedin Figs.1 and2(Haasnootetal.,2011,2012).Centraltoadaptationpathways areadaptiontippingpoints(Kwadijketal.,2010),whicharethe conditions under which an action no longer meets the clearly specifiedobjectives.Thetimingoftheadaptationpointforagiven action, its sell-bydate, is scenariodependent. After reaching a tippingpoint,additionalactionsareneeded.Asaresult,apathway emerges.TheAdaptationPathwaysapproachpresentsasequence ofpossibleactionsafteratippingpointintheformofadaptation trees (e.g. like a decision tree or a roadmap). Any given route throughthetreeisanadaptationpathway.Typically,thisapproach usescomputationalscenarioapproachestoassessthedistribution ofthesell-bydateofseveralactionsacrossalargeensembleof transientscenarios.Thisdistributioncanbesummarizedin box-whisker plots, and the median or quartile values are used in generatinganadaptationmap.Theexactdateofatippingpointis notimportant;themomentshouldberoughlyright—forexample, ‘‘onaveragethetippingpointwillbereachedwithin50years,at earliestwithin40years,andatlatestwithin60years’’.Theeffects of sequences of actions can be assessed in the same way as individual actions. To cope with the presence of different stakeholders,values, and worldviews, culturalperspectives can beusedtomaptheseout(Hoekstra,1998;Middelkoopetal.,2004; Offermansetal.,2011;VanAsseltandRotmans,1997).

The Adaptation Pathways map, manually drawn based on modelresultsorexpertjudgment,presentsanoverviewofrelevant pathways(seeFig.2foranexample).SimilartoaMetromap(see, for example, http://www.wmata.com/rail/maps/map.cfm), the Adaptation Pathwaysmap presents alternativeroutes toget to thesamedesiredpointinthefuture.Allroutespresentedsatisfya pre-specifiedminimumperformancelevel,suchasasafetynorm(a thresholdthatdetermineswhetherresultsareacceptableornot). Theycan,thus,beconsideredas‘differentwaysleadingtoRome’ (asis true of differentroutes toa specifieddestinationon the Metro).Also,themomentofanadaptationtippingpoint(terminal station),andtheavailableactionsafterthispoint,areshown(via transfer stations). Due to unacceptable performance of some actionsin a selection of scenarios,someroutes are not always available(dashedlines).Decisionmakersorstakeholdersmayhave apreferenceforcertainpathways, sincecostsandbenefitsmay differ.Anoverviewofsuchcostsandbenefitsforeachpathwaycan be presented in a scorecard (e.g. Walker, 2000). With the

adaptationmap, decisionmakers canidentifyopportunities, no-regret actions,lock-ins, andthetimingofanaction,inorderto supportdecisionmakinginachangingenvironment.Thatis,the adaptationmapcanbeusedtopreparea planforactionstobe takenimmediately,andforpreparationsthatneedtobemadein order to beable to implement an action in the future in case conditionschange.TheexampleofFig.2showsthatactionsare neededintheshort-term.ChoosingactionBmaybeineffectiveas soon additionalactionsare needed.ChoosingoptionCinvolves takingarisk,asadditionalactionsmaybeneededincasescenario Xbecomesreality.Incombinationwithascorecardofthecostsand benefits for the pathways, a decisionmaker could make an informeddecision.

2.2. AdaptivePolicymaking

Adaptive Policymaking is a generic structured approach for designingdynamicrobustplans(Kwakkeletal.,2010a;Marchau etal.,2009; Rangeret al.,2010). Conceptually,Adaptive Policy-making is rootedin Assumption-Based Planning (Dewar et al., 1993). Fig. 3 shows the steps of the Adaptive Policymaking approachfordesigningadynamicadaptiveplan(Kwakkeletal., 2010a).InStepI,theexistingconditionsofasystemareanalyzed andtheobjectivesforfuturedevelopmentarespecified.InStepII, thewayinwhichtheseobjectivesaretobeachievedisspecifiedby assembling a basic plan. This basic plan is made more robust throughfourtypesofactions(StepIII):mitigatingactions(actions to reduce the likely adverse effects of a plan); hedging actions (actionstospreadorreducetheuncertainadverseeffectsofaplan); seizing actions (actions taken to seize likely available opportu-nities); and shaping actions (actions taken to reduce failure or enhancesuccess).EvenwiththeactionstakeninStepIII,thereis stilltheneedtomonitortheplan’sperformanceandtotakeaction ifnecessary.Thisiscalledcontingencyplanning(StepIV).Signposts specifyinformationthatshouldbetrackedinordertodetermine whether the plan is meeting the conditions for its success.In addition, critical values of signpost variables (triggers) beyond which additionalactions should be implementedare specified. Therearefourdifferenttypesofactionsthatcanbetriggeredbya signpost,whicharespecifiedinStepV:defensiveactions(actions takentoclarifythebasicplan,preserveitsbenefits,ormeetoutside challengesinresponsetospecifictriggersthatleavethebasicplan unchanged); corrective actions (adjustments to the basic plan); capitalizingactions(actionstotakeadvantageofopportunitiesthat canimprovetheperformanceofthebasicplan);andareassessment oftheplan(initiatedwhentheanalysisandassumptionscriticalto theplan’ssuccesshaveclearlylostvalidity).

Oncethecompleteplanhasbeendesigned,theactionstobe takenimmediately(fromStepIIandStepIII)areimplemented,and amonitoringsystem(fromStepIV)isestablished.Thentimestarts running,signpostinformationrelatedtothetriggersiscollected, andactionsarestarted,altered,stopped,orexpandedinresponse tothisinformation.Afterimplementationoftheinitialactions,the implementationofotheractions(fromStepV)issuspendeduntila triggereventoccurs.

2.3. Comparisonoftheapproaches

Table1compares thefeaturesof AdaptivePolicymaking and Adaptation Pathways. Bothapproaches aimat supporting deci-sionmakersinhandlinguncertaintyinlong-termdecisionmaking andemphasizetheneedforadaptivityinplansinordertocope withdeepuncertainty.Morespecifically,theybothoffersupportin choosingnear-termactions,whilekeepingopenthepossibilityto modify,extend,orotherwisealtertheplansinresponsetohowthe futureunfolds.

Evaluateactions&develop pathways

Policyanalysis

Describecurrent&future situations,objectives

Problemanalysis

Determineactions

Analyseensemblesof transientscenarios Determinesell-bydate

ofactions

Currentpolicy ActionA ActionB ActionC ActionD 0 10 70 80 90_years100 1 2 3 4 5 6 7 8 9 Path actions Side effects Relative Costs Target effects +++ ++ 0 -- -0 0 0 --- -+ 0 +++ +++ +++++ ++++ +++ + + 0 0 0 0 0 0 + Scorecardpathways

AdaptationPathwaysMap

Transferstationtonewaction

AdaptationTippingPointofanaction(Terminal) Actioneffectiveinallscenarios

ActionnoteffectiveinscenarioX

Fig.2.AnexampleofanAdaptationPathwaysmap(left)andascorecardpresentingthecostsandbenefitsofthe9possiblepathwayspresentedinthemap.Inthemap, startingfromthecurrentsituation,targetsbegintobemissedafterfouryears.Followingthegraylinesofthecurrentpolicy,onecanseethattherearefouroptions.ActionsA andDshouldbeabletoachievethetargetsforthenext100yearsinallclimatescenarios.IfActionBischosenafterthefirstfouryears,atippingpointisreachedwithinabout fiveyears;ashifttooneoftheotherthreeactionswillthenbeneededtoachievethetargets(followtheorangelines).IfActionCischosenafterthefirstfouryears,ashiftto ActionA,B,orDwillbeneededinthecaseofScenarioX(followthesolidgreenlines).Inallotherscenarios,thetargetswillbeachievedforthenext100years(thedashed greenline).ThecolorsinthescorecardrefertheactionsA(red),B(orange),C(green),andD(blue).

Necessary Conditions for Success Objectives Constraints Definitions of Success Options Set Policy Actions

II . Assembling the Basic Plan

Signposts Mitigating Actions (M) Hedging Actions (H) Triggers Likely Vulnerabilities Uncertain Vulnerabilities

III. Increasing the Robustness of the Basic Plan

V. Preparing the Trigger Responses

Defensive Actions (DA) Corrective Actions (CR) Reassessment (RE)

Other’s Actions Unforeseen Events Changing Preferences

I . Setting the Stage

Vulnerabilities and Opportunities

Likely Opportunities

Seizing Actions (SZ)

IV . Setting up the Monitoring System

Capitalizing Actions (CP) Shaping Actions (SH)

Thewaysinwhichthetwoapproachesofferdecisionsupport arequitedifferent.AdaptationPathwaysprovidesinsightintothe sequencing of actions over time, taking into account a large ensembleoftransientscenarios.Thetransientscenariosallowfora wide variety of uncertainties about future developments to be takenintoaccountintheplanningprocess.Notonlytrendsand systemchangesareincluded,butalsouncertaintyduetonatural variability.Theuseofafastandsimplemodelallowsforexploring awidevarietyofpathwaysovertheensemble.Theseresultscanbe usedtosketchanAdaptationPathwaysmap.Dynamicrobustness oftheresultingplanisindirectlyhandledthroughthe identifica-tionofanadaptationtippingpoint,thesell-bydate,andtheshiftto other actions. The pathways map provides information to the decisionmaker,butgivesnoguidanceonhowthedecisionmaker cantranslatethisintoanactualplan.

Adaptive Policymaking supports the decisionmaker in a different way. It specifies a stepwise approach to designing a plan.First abasiccourseofaction isdevelopedin light ofwell specifiedobjectives.Then,thevulnerabilitiesandopportunitiesof thiscourseofactionareidentified,anddifferenttypesofactionsto betakennoworinthefuturetoeithercopewiththevulnerabilities or capitalize on the opportunities are specified. Through the identificationofopportunitiesandvulnerabilities,awidevarietyof uncertainties can be accounted for. The specification of a monitoringsystemandassociatedactionsresultsinadynamically robust plan. However, Adaptive Policymaking offers no clear guidancebeyondtheseconcepts.Thatis,questions,suchashow can one identify vulnerabilities, how should the actions be sequenced,orhowdoesonedecide whethertohedgeagainsta vulnerabilityortospecify a monitoringsystemwithactions to handlethevulnerabilityinthefutureifandwhenitarises,arenot addressedexplicitly.

3. Anewapproach:dynamicadaptivepolicypathways

The combination of Adaptive Policymaking and Adaptation Pathways, which we call Dynamic Adaptive Policy Pathways, resultsfromusingthestrengthsofbothapproaches.Inshort,this integratedapproach includes: transient scenarios representinga varietyofrelevantuncertaintiesandtheirdevelopmentovertime;

differenttypesofactionstohandlevulnerabilitiesand opportu-nities; Adaptation Pathways describing sequences of promising actions;andamonitoringsystemwithrelatedcontingencyactionsto keeptheplanonthetrackofapreferredpathway.Thestepsinthe approacharepresentedinFig.4.

Thefirststepistodescribethestudyarea,includingthesystem’s characteristics, the objectives, the constraints in the current situation,andpotentialconstraintsinfuturesituations.Theresult is adefinitionof success,whichis aspecification ofthedesired outcomes in terms of indicators and targets that are used in subsequent steps to evaluate the performance of actions and pathways, and to assess the ‘sell-by dates’ of the actions. The descriptionofthestudyareaincludesaspecificationofthemajor uncertaintiesthatplayaroleinthedecisionmakingproblem.These uncertaintiesarenotrestrictedtouncertaintiesaboutthefuture, Table1

Comparisonoftheapproaches.

Aspect AdaptivePolicymaking AdaptationPathways

Focus Startsfromavisionofthedecisionmakerandcreates aplanforrealizingthisvisionandprotectingitfrom failure.

Exploresactionsforachievingobjectivesovertime byincludingdynamicinteractionbetweenthe systemandsociety.

Considerationofthemultiplicityoffutures Indirectlyviavulnerabilitiesandopportunities. Explicitlyviatransientscenarios. Planningprocess Comprehensivestepwiseapproachfordesigninga

plan.

ShortstepwiseapproachfordesigningAdaptation Pathways.

Clarityonhowtodesignaplan Limited;ahighlevelframeworkthatcanbe translatedintoaspecificplaninmanydifferent ways.

Applicationoriented,withaclearlinktotheuseof modelstodevelopaspecificplan.

Typesofactionsthatcanbetaken Distinguishesmanydifferenttypesofactionsthat canbetaken(e.g.hedging,mitigating,andshaping).

Nospecificcategorizationofactionsisused.Several actionsandpathwaysarepresented.Avarietyof actionsareidentifiedbasedondifferentsocietal perspectives.

Desirableplan Onebasicplanisdeveloped.Noclearguidelineon howdevelopthebasicplan.

Severalpathwaysarepresented.Different perspectivesresultindifferentpreferredpathways. Nofocusonhowtoidentifypromisingpathways whenconfrontedwithalargenumberofpossible actions.

Considerationoftypesofuncertainties Inprinciple,anyuncertaintycanbeaccountedfor. Inprinciple,anyuncertaintycanbeaccountedfor. Explicitattentionisgiventosocialuncertainty. Flexibilityofresultingplan Flexibilityisestablishedthroughthemonitoring

systemandassociatedactions.

TheAdaptationPathwaysmapclearlyspecifieswhen apolicyshouldbechanged,andwhatthenextaction shouldbe.

Dynamicrobustnessofresultingplan Dynamicrobustnessresultsfromthemonitoringset upinStepIVandtheactionstakeninStepV.

Dynamicrobustnessisproducedindirectlyviathe ideaofa‘sell-bydate’andtheshifttoanotheraction.

butcanalsocoveruncertaintiesrelatedtothedataormodelsthat arebeingused(Kwakkeletal.,2010b).

Thesecondstepistheproblemanalysis.Inthisstep,thecurrent situation and possible future situations are compared to the specifiedobjectivestoidentifywhetherthereareanygaps.The possiblefuturesituationsare‘referencecases’assumingno new policiesareimplemented,andconsistof(transient)scenariosthat spantheuncertaintiesidentifiedinstepone.Agapindicatesthat actionsareneeded.Bothopportunitiesandvulnerabilitiesshould beconsidered. Opportunitiesaredevelopmentsthatcanhelpin achievingtheobjectives,whilevulnerabilitiesaredevelopments thatcanharmtheextenttowhichtheobjectivescanbeachieved. Theidentificationofopportunitiesandvulnerabilitiescanbebased on the analysis of the reference cases, which can best be accomplishedusingacomputationalmodel.

Inthethirdstep,oneidentifiespossibleactionsthatcanbetaken to meet the definition for success. These actions can thus be specifiedinlight oftheopportunitiesand vulnerabilities previ-ouslyidentifiedandcanbecategorizedaccordingtothetypesof actions specifiedin the Adaptive Policymaking framework (i.e. shaping,mitigating,hedging,andcapitalizingactions).Theaimof this step is to assemble a rich set of possible actions. An identificationof actionsfordifferentperspectives couldenforce this(e.g.donebyOffermansetal.,2011).

The fourth step is toevaluate the actions. Theeffects of the individualactionsontheoutcomeindicatorsareassessedforeach ofthescenariosandcanbepresentedusingscorecards.Theresults are used to identify the sell-by date for each of the actions. Furthermore, the vulnerabilities and opportunities need to be reassessed.Wastheactionabletoreduceorremoveaspecified vulnerability?Wastheactionabletoutilizeaspecified opportu-nity?Does the action create new opportunitiesand/or vulner-abilities?Ineffectiveactionsarescreenedout(Walker,1988),and onlythepromisingactionsareusedinthenextstepsasthebasic buildingblocksfortheassemblyofAdaptationPathways.

Thefifthstepistheassemblyofpathwaysusingtheinformation generated in the previous steps. It is conceivable that the reassessment of the vulnerabilities and opportunities in the previoussteptriggersaniterativeprocess(backtostep3)wherein neworadditionalactionsareidentified.Oncethesetofactionsis deemedadequate,pathwayscanbedesigned.Apathwayconsists ofaconcatenationofactions,whereanewactionisactivatedonce itspredecessorisnolongerabletomeetthedefinitionofsuccess. Pathways can be assembled in different ways. For example, analystscouldexploreallpossiblerouteswithallavailableactions. Eachoftheseroutescanthenbeevaluatedon itsperformance. However,someactionsmayexcludeothers,andsomesequencesof actionsmaybeillogical.Inaddition,fundamentalcriteria,suchas theurgencyofactions,theseverityoftheimpacts,theuncertainty involved,and thedesiretokeepoptionsopen,couldbeusedto developa setofpromisingpathways.Theresultisanadaptation map,whichsummarizesalllogicalpotentialpathwaysinwhich ‘success’(asdefinedinstep1)isachieved.Notethatactionsneed notbeasingleaction,butcanbeaportfolioofactions,constructed afteriterationofsteps3–5.

Thesixthstepistodevelopamanageablenumberofpreferred pathways.Preferredpathwaysarepathwaysthatfitwellwithina specified perspective. It can be useful to specify two to four pathwaysthatreflect differentperspectives.Thiswillresultnot onlyintheidentificationofphysicallyrobustpathways,butalso ‘sociallyrobust’pathways(Offermansetal.,2011).Thepreferred pathwayswillformthebasicstructureofadynamicadaptiveplan (likethebasicplanintheAdaptivePolicymakingframework).

Theseventhstepistoimprovetherobustnessofthepreferred pathwaysthroughcontingencyplanning–inotherwords,todefine actionstogetandkeepeachofthepathwaysontrackforsuccess.

Ingeneral,theseareactionstoanticipateandprepareforoneor morepreferredpathway(e.g.keepoptionsopen),andcorrective actionstostayontrackincasethefutureturnsoutdifferentlythan expected.Wedistinguishthreetypesofcontingencyactionsfrom Adaptive Policymaking: corrective, defensive, and capitalizing actions,whichareassociatedwithamonitoringsystemandtrigger values.Themonitoringsystemspecifieswhattomonitor,andthe triggersspecifywhenacontingencyactionshouldbeactivated.

Theeighthstepistotranslatetheresultsfromalloftheprevious stepsintoa dynamicadaptive plan.Thisplanshouldanswerthe followingquestion:Giventhesetofpathwaysandthe uncertain-tiesaboutthefuture,whatactions/decisionsshouldwetakenow (and which actions/decisions can be postponed)? The plan summarizestheresultsfromtheprevioussteps,suchastargets, problems,andpotentialandpreferredpathways.Thechallengeis todraftaplanthatkeepsthepreferredpathwaysopenforaslong as possible. Thus, the plan specifies actions to be taken immediately, actions to be taken now to keep open future adaptations,andthemonitoringsystem.

Finally,theactionstobetakenimmediatelyareimplemented andthemonitoringsystemisestablished.Then,timestartsrunning, signpostinformationrelatedtothetriggersiscollected,andactions are started, altered, stopped, or expanded in response to this information.Afterimplementationoftheinitialactions,activationof otheractionsissuspendeduntilatriggereventoccurs.

4. Casestudy:RhineDeltaintheNetherlands

WeillustrateandtesttheapproachofDynamicAdaptivePolicy PathwaysforthelowerRhineDeltaintheNetherlands,andfocus ontheIJsselmeerarea.In2007,theGovernmentestablishedthe SecondDeltaCommissionforidentifyingactionstopreventfuture disasters (Deltacommissie, 2008; Kabat et al., 2009), since the expectedfutureclimatechangeandsealevelrise‘cannolongerbe ignored’ (Deltacommissie,2008, p. 5).The Commission’s advice resultedintheenactmentofa DeltaAct,andispresentlybeing elaborated in a Delta Programme. The chair of the Delta Programme summarized their main challengeas follows: ‘‘One ofthe biggestchallengesisdealingwithuncertaintiesinthefuture climate,butalsoinpopulation,economyandsociety.Thisrequiresa newwayofplanning,whichwecalladaptivedeltaplanning.Itseeksto maximize flexibility; keeping options openand avoiding ‘lock-in’’’

(Kuijken, 2010). This corresponds well with our integrated

approach, and thus provides an appropriate case to useas an illustration.However,wehavemademanysimplifying assump-tions.So,whatfollowscanbeusedonlyforillustrativepurposes andafirsttentativetestofourapproach.Thestepswemention refertothestepsinFig.4.

4.1. Steps1and2:currentsituationandproblemanalysis

TheNetherlandsisadenselypopulatedcountry,two-thirdsof whichisvulnerabletobeingfloodedbytheseaorlargerivers.A sophisticated and comprehensive water management system satisfies the water system requirements for living in a delta. But,forcopingwithfuturechangessuchasglobalclimatechange, adaptationmaybeneeded.Havingtherightamountofwaterfor users,attherighttime,intherightplace,andatsociallyacceptable costsisakeytargetfortheMinistryofTransport,PublicWorksand WaterManagement(Rijkswaterstaat,2011).Theobjectiveofthe DeltaProgrammeis‘‘toprotecttheNetherlandsfromfloodingandto ensureadequatesuppliesoffreshwaterforgenerationsahead.’’(Delta Programme,2011). Accordingly,we define‘success’ asfollows: ‘Theplanwillbesuccessfulifnofloodsoccur,andifthereisenough freshwaterduringthenext100years.Thefrequencyofwatershortage willbeatleast similartothepresentsituation(oncein10yearsa

watershortagemayoccur).’Constraintswouldincludethevarious EU Directives that the Dutch Government must follow. For example,theWaterFrameworkDirectiveimpliesthatecological and water quality objectives have to be met. These Directives imply that we need to add anothertarget to our definitionof success:‘theplanwillbesuccessfulifitdoesnotresultinnegative impactsonnature’.

4.1.1. Thewatersystemanditsfunctionsinthecurrentsituation Thereareseveral keywatercharacteristicsthatneedfurther explanationforourcase(see Fig.5).After theRhineentersthe country,thewaterisdistributedoverthreebranches–theWaal, Nederrijn, and IJssel – by means of a weir at Driel. The IJssel suppliestheIJsselmeerandMarkermeerlakeswithfreshwater. TheAfsluitdijkdamprotectstheadjacentareasfromfloodingand enableswaterstorageinthelakes.ThelevelsoftheIJsselmeerand Markermeerarecarefullymaintainedwithsluices,toensuresafety inthewinterandenoughfreshwaterinthesummer.Safetyfrom floodingisexpressedinstandardsofaprobabilityperyearthata criticalwaterlevelwilloccur–e.g.1:1250years(Rijkswaterstaat, 2011). Thesestandards(also called‘norm frequencies’) arelaid downbylawforeverydikeringarea,anddependlargelyonthe economic activities, the number of inhabitants, and flood characteristics associated with the dike ring. The Haringvliet sluicegatesandtheMaeslantkeringprotecttheRhineestuaryfrom (mainlycoastal) flooding.TheHaringvliet sluicesalsolimit salt intrusionintotheriver.

TheIJsselmeerandMarkermeerarethemainwaterreservoirs in thelowerRhineDelta.During dryperiods, waterfromthese lakesisusedtosupplylargepartsoftheNetherlands.Despitethe extensivenetworkofditchesandcanalsandthelargeamountof waterstorage,thewatersupplyisinsufficienttofulfillthefresh waterdemandsduringdryperiods.Duringsuchperiods,apriority listisusedtodistributefreshwaterfordifferentuses.Themajor usesofwater areforagriculture(forirrigation),forflushing (to mitigateadverseimpactsforagricultureanddrinkingwaterfrom the upward seepage of salt water and salt intrusion in the waterwaysnearRotterdam),andforwatermanagementitself(to maintainwaterlevelsinthelakesandcanals).Drinkingwaterand industryarealsoimportantuses,althoughthequantityusedfor theseisnegligiblecomparedtotheotheruses.

4.1.2. Thewatersystemanditsfunctionsinthefuture

Futuresocio-economicdevelopments,climatechange,andsea levelrise,mayrequirechangestothewatermanagementsystem. Recently, four water-related scenarios were developed for the Netherlands(Bruggemanetal.,2011;TeLindeetal.,submitted). These‘Deltascenarios’covertworepresentationsoffutureclimate (based on Van den Hurk et al., 2007) and two sets of socio-economicdevelopmentsintheNetherlands.Theclimatescenarios cover a range from moderate increases in temperature and precipitation(18C,3.6%precipitationinthewinter,and2.8% in thesummer;usedinthescenario‘Crowd’)toalargetemperature increase (28C in 2100; used in the scenario ‘Warm’), a large

precipitationincreaseinwinter(14.2%),andalargeprecipitation decreasein thesummer(19%). Thesea level canincrease (35– 85cmin2100).Thesocio-economicscenariosdescribea popula-tionchangefromthecurrent16millionto12millionor24million in 2100,together withmajor changes in agricultural land use. Thesescenarioswouldresultinanincreaseinwaterdemandsfrom theregionalareastothenationalwatersystemduetolessrainand lower river discharges, more salt intrusion, and/or agricultural changes;andanincreaseinfloodriskduetosealevelrise,higher riverdischarges,andpopulationandeconomicgrowth.

4.2. Step3:determineactions

Forillustrativepurposes,wefocusontheIJsselmeerarea,and considerinouranalysisonlythemainalternativeactions,whereas inrealitytheentireRhineDeltaandallkindsofcombinationsof actionsarepossible.Asaresultofourproblemanalysis,itisclear thattheIJsselmeerareawillbecomeevenmoreimportant asa storagebasinforprovidingfreshwaterintimesofdrought.Either thewaterstoragecapacityneedstobeincreased,orthe(growthin) waterdemandneedstobereduced.Toincreasethewaterstorage, thewaterleveloflakeIJsselmeercanbeeitherincreasedinthe spring,and then used during dry periods, or decreased in dry periods. Water demands can be reduced by increasing the efficiencyof water usein theregional system, by changing to saltand/ordroughttolerantcrops,and/orbydecreasing agricul-tureormovingagriculturetoareaswithappropriate environmen-tal conditions. Some of these actions can be taken without changingthecurrentinfrastructure;thesecanbeconsidered as improvements of the current system. For other actions, the infrastructurewouldhavetobechangedconsiderably.Toensure safetyfromfloodingincaseofsealevelriseandincreasedriver dischargesinthewinter,floodmanagementactionswouldneedto betakenaswell.SafetyfortheareasadjacenttotheIJsselmeercan beachievedbyeitherraisingthewaterlevelin correspondence withthesealevel,sotheexcesswatercanbedrainedundergravity intotheWaddensea(ofcourse,dikesneedtoberaisedaccordingly aswell),orbybuildinglargepumpsfordischargingwaterintothe

Waddensea.Ifthefirstactionischosen,theextraamountofwater canbeusedin timesofdrought.Ifthesecondaction ischosen, waterinletsandshippingsluicesneedtobeadaptedforenabling wateruseduringdrought.Table2providesanoverviewofthisset ofactions.

4.3. Step4:assessefficacy,sell-bydateofactions,andreassess vulnerabilitiesandopportunities

Table2presentsanassessmentoftheefficacyofeachindividual actionanditssell-bydatebaseduponexpertknowledge,previous studiesonpossibleactions,andpreliminarymodelingresultsfor 2050and2100indicatinghowmuchwater(incmIJsselmeerlake level)isneededtosupplytheamountofwaterdemandedforan average,dry, andextremelydry yearforthedifferentscenarios (Klijnetal.,2011).Fordeterminingthesell-bydate,weassumea linearchangeofclimateand socio-economicdevelopments.For theactions focusing on reducing the water demand,no model resultswereavailable.Togetherwithstakeholders(waterboards) theimpact of theseactions wastranslated into theamount of IJsselmeerwaterneeded.Table2showsthatthecurrentplanis likelytobesufficientforachievingobjectivesforapproximately30 years.Afterthispoint,changesarelikelytobeneeded. Improve-mentsthatcanbemadetothecurrentsystemshouldenablethe sell-bydatetobeextendedbyapproximately10years.

Thefloodmanagementactionsandtheactionsforfreshwater supplyinfluenceeach other.Ahigherwater levelforincreasing storage capacity will, at the same time, allow the system to dischargeunder gravity(depending on thesealevel). If policy-makers were to decide to ensure safety against flooding by increasingthepumpcapacityandkeepingthesametargetwater level,freshwatersupplyactionswithanincreaseofthewaterlevel wouldbescreenedout.Thereisalsoarelationbetweentheactions intheIJsselmeerareaandotherregionsinthelowerRhineDelta. Forexample,aspartoftheactionstoensuresafetyalongtheWaal andNederrijn,moreRhinewatercouldbedistributedtotheIJssel. Inthiscase,enoughcapacityshouldbeavailableintheIJsselmeer, implying that the water level can be raised at earliest in the

Table2

Actionsandassessmentoftheirrelativeperformanceintermsofimpactsonsafety,freshwatercapacity,sideimpactsonnatureareasandshippingintheIJsselmeerandIJssel region,andsell-bydateofactionsbasedonpreliminaryexpertknowledgeandmodelingresults.a

Action Impact Sell-bydate(years) Costs

Safety Freshwater Nature Shipping Floodmanagementactions

Increasetargetwaterlevelandthedikescorrespondinglyforenabling dischargingundergravitytosea.

+++ ++ >2100 +++

Keepthesametargetwaterlevelbyincreasingpumpcapacitylargely. +++ 0 0 0 2100 ++

Freshwatersupplyactions

Increasewaterlevelto+1.1minspring,andadaptregionalwater systeminfrastructure.MorewatertotheIJsselRiverinspring.

+++b

++ >2100 ++

Increasewaterlevelto+0.6minspring,andadaptregionalwater systeminfrastructure.MorewatertotheIJsselRiverinspring.

++b

+ 2070–2090 +

Increasewaterlevelto+0.1m,usingcurrentinfrastructure +b

+ /+ 0 2050–2060 0

Decreasewaterlevelto 0.8mindryperiods,andadaptinfrastructure. 0 +++ + 2100 ++

Decreasewaterlevelto 0.6mindryperiods,andusecurrentinfrastructure. Acceptnavigationobstructionsduringextremedroughts

0 ++ + 2060–2070 +

AdaptwaterdistributionRhinebranches:morewaterto IJsselRiverduringdroughts

0 + 0 + 2040 0

Improvingcurrentplanwithflexiblewaterlevels 0 + 0 0 2030–2040 0

Reducewaterdemandtothenationalwaternetwork,byimprovingthe managementoftheregionalnetwork

0 + 0 0 2050–2070 +

Reducewaterdemandanddamagebychangingtosaltand/or droughttolerantcrops

0 +++ 0 0 >2100 ++

Reducewaterdemandbychangelandusetonatureand/or urbanareas

0 +++ ++ 0 >2100 +

a _{largenegativeimpact, negativeimpact,0noorminorimpact,+positiveimpact,++moderatepositiveimpact,+++largepositiveimpact.} b_{TheseimpactsareconsideredaspositiveasthisfacilitatesthepreferreddrainageofexcesswaterfromtheIJsselmeertotheWaddenseaundergravity.}

beginningofspring.Insomeyears,therewillnotbeenoughwater todothis.Startingearlierwithraisingthewaterlevelwouldbe possibleonlyifthedikeswereraisedsufficiently.Ifmorewateris transported tothe IJssel, there will beless water for theriver branchestothewesternpartofthecountry(WaalandNederrijn), andthuslesswaterforholdingbackthesaltintrusionfromthesea, makingthewater inletat Goudaless reliable.In that case, the MidwestareamightbesuppliedbyIJsselmeerwater.If,however, policymakersweretodecidetoclosetheRhineestuary,thiswould notbenecessary.

Withtheimpactsoftheactionsinmind,thevulnerabilitiesand opportunitiesneedtobereassessed.Forexample,iftheIJsselmeer level is raised, achieving the EU Directives (Water Framework Directive,HabitatDirective,BirdsDirective)maybeendangered, due to the disappearance of shallow waters that provide an importanthabitatforspecies.

4.4. Step5:developpathways

Fig.6showstheAdaptationPathwaymapforthe10actionsfor fresh water supply from Table 2. For flood management, two actionsareavailable. Theyare notpresentedin theAdaptation Pathways map, but they influence the preferences for certain pathways,asexplainedabove.

Toconstructthepathways,theactionsaregroupedintoactions influencingwaterdemandandactionsinfluencingwatersupply. Actionswithlongsell-bydatesareshownonthetoporbottomof themap,whileactionswithshortsell-bydatesareshowncloseto thecurrentplan.Thenextstepistoaddthesell-bydatesandallthe possibletransferstootheractionsthatwouldextendthesell-by date.Sometimesactionsaffecteachother.Ifthesell-bydateforan actionwillincreaseconsiderably,thisisshownbyanadditional line in the same color. Next, illogical actions are eliminated (backgroundcolorincontrasttobrightcoloredlogicalactions).For example,implementingoneofthelargeactionsfirstisillogical,as this may not be necessary to achieve success, and it can be implementedlateraswell.Itisalsolesslogical,oncepolicymakers havechosentosignificantlyadjustthewaterlevel,toswitchto changingthecroptypeorlanduse.Thesell-bydateofanaction dependsonthescenarioandtheobjectives.Thisisshownwiththe twox-axes,oneforeachscenario.

4.5. Step6:selectpreferredpathways

FromtheAdaptationPathwaysmap,preferredpathwayscanbe selected. Different decisionmakers and stakeholders can have different preferred pathways, depending on their values and beliefs.Fig.7presentsanexampleofthepreferredpathwaysfor

Raiselevel+1.1minspring

Changetodrought/salt

tolerantcrops

RaiseIJsselLakelevel

withincurrentinfra+0.1m

Decreaselevelwithin

currentinfra(-0.6m)

Decreaselevelandadapt

infrastructure(-0.8m)

MorewaterthroughIJssel

Raiselevel+0.6m

Changelanduse

Moreefficientwateruse

Optimisingcurrentpolicy

Water

de

mand

actions

Water

supply

actions

Transferstationtonewaction AdaptationTippingPointofanaction(Terminal) AdaptationPathways Fig.6.AdaptationpathwaysmapforfreshwatersupplyfromtheIJsselmeerarea.

archetypes of three perspectives: Hierarchist, Egalitarian, and Individualist(seee.g.Hoekstra,1998;Middelkoopetal.,2004on these perspectives related to water). For example, Hierarchist believes in controlling water and nature, assigning major responsibilitiestothegovernment.Thismeansa preferencefor actions related to managing water levels and water use. The Egalitarianfocuses on theenvironmentand equity, resultingin strategiesfordecreasingwaterdemandsbyadaptingfunctionsto theirenvironment(othercropsortheirrelocation).The Individu-alistadherestoaliberalmarketandahightrustintechnologyand innovation.Thismeansapreferenceforfacilitatingtechnological developments for more efficient with water use and drought tolerantcroptypes.Portionsofthepreferredpathwaysaresimilar. Thepointatwhichthepathsstarttodivergecanbeconsideredasa decisionpoint.Inourcase,therearethreedecisionpoints:(1)after ‘currentplan’,(2)after‘raisetheIJsselmeerlevelwithincurrent infrastructure’, and (3) after ‘more efficient water use’. The preferredpathwayscouldbeastartofadiscussiononanadaptive plan.Inaddition,combinationsofthesepathwayscouldbedrawn aspathsthathavesupportfrommorethanoneperspective.For example,starting with‘moreefficientwateruseintheregional areas’couldbefollowedbyasmallraisingoftheIJsselmeerwater level(+0.1m),and,ifneeded,thatwaterlevelcanberaisedmore,

orthewaterdemandcouldbereducedbychangingcroptypes.The short-termactionisonethatallperspectivescouldagreeupon,and canthusbeconsideredasociallyrobustaction(Offermansetal., 2011).

4.6. Step7:determinecontingencyactions,signposts,andtriggers

Togetorstayonthetrackofapathway,contingencyactionscan bespecified. Forexample, theGovernmentcouldstimulate the growthofsaltand/ordroughttolerantcropswithsubsidies,orby limiting water availability and holding farmers responsiblefor finding‘enough’water.Keepingtheoptionopenforanincreaseof theIJsselmeerlevelwillrequirespatialplanningrules(e.g.allow adaptivebuildingonlyoutsidethedikerings).Ifstructuresneedto bereplaced,theycanbebuiltsuchthattheyarealreadyableto copewithfutureactions.Correctiveactionsneedtobetakento achieve objectives for nature. Constructing shallow zones and islandscanmitigatethenegativeimpactsofraisingthewaterlevel. Thiscanbringopportunitiesfordredgingcompanies.

Wedistinguishthreedifferentgroupsofsignpostsandtriggers: (1) trends and events in the natural environment (the water system);(2)human-drivenimpactsonthewatersystem,suchas theautonomousadaptationoffarmersorachangeinupstream Raiselevel+1.1minspring

Changetodrought/salt tolerantcrops RaiseIJsselLakelevel withincurrentinfra+0.1m Decreaselevelwithin currentinfra(-0.6m) Decreaselevelandadapt infrastructure(-0.8m)

MorewaterthroughIJssel Raiselevel+0.6m

Changelanduse Moreefficientwateruse Optimisingcurrentpolicy

Water d emand a ctions Water supply actions

PrefferedpathHierarchistPerspective:largerolegovernment,controllingthesystem PrefferedpathEgalitarianperspective:protectenvironment,equity

PrefferedpathIndividualistPerspective:marketdrivensociety,smallroleforgovernment

Currentpolicy

2050 2100

2100 2050

Transferstationtonewaction AdaptationTippingPointofanaction(Terminal) AdaptationPathways

ScenarioWarm ScenarioCrowd

wateruse;and(3)societalperspectivesaboutthefuture,suchas expectations about climate change and population growth, knowledgeabout(orbeliefin)theeffectivenessofcertainpolicies, andsocietalvalues, suchas thewish toprotectnatureand the amountofacceptedflood/droughtrisk.Theamountofagricultural areaandthecropsusedcouldbeanappropriatetriggerforchanges inwaterdemand,sincetheycanbewellmonitoredandchange slowlyovertime.

4.7. Step8:specifyadynamicadaptiveplan

Based on the problem, objectives, and pathways from the previous steps, a dynamic adaptive plan can be specified. Consideringthescenarios, theamountofwaterstorage needed inthefuturerequiresuptoa1.5mwaterlevelintheIJsselmeer. Raisingthewaterlevelisthepreferredactionfromasafetypointof view, because in that case water can be discharged to the Waddenseaundergravity.However,intheshort-andmid-term (<2080)thisactionisnotneeded.Tokeepthisoptionopen,spatial planningrulescouldbeimplemented.Initialactionscanfocuson improvingtheperformanceofthecurrentplanbyintroducinga flexiblewater level (e.g.outside thegrowingseason, thewater levelmaydrop) and makingmoreefficientuseof waterin the regionalareas (e.g.have a separatearea for brackish and salty groundwater,inordertodecreasetheamountofwaterneededfor flushing).Tokeepotheroptionsopen,theGovernmentcouldinvest inresearchanddevelopmentofdroughtand/orsalttolerantcrops. Theplanforfutureactionsneedstobeready,incaseawindowof opportunity arises for adapting the water system to potential future conditions. Anexample of suchan opportunityis when infrastructure(sluices, dams,etc.)requiresmaintenance. Atthe sametime asmaintenance is beingcarriedout,newstructures couldbeaddedthat wouldbeabletocopewithanincreaseor decreaseofthewaterlevelintheIJsselmeer.HuqandReid(2004)

assign the label ‘mainstreaming’ to actions that incorporate ‘‘potential climate change impacts into ongoing strategies and plans’’.Anotherwindowforopportunityarisesinthecaseofadry year.Insuchayear,societalsupportforimplementingsuchactions islikelytobehigher.

4.8. Steps9and10:implementationofdynamicadaptiveplanand monitoring

The first actions of the plan are implemented, and the Government continues monitoring sea level rise and climate changes.Furthermore,theGovernmentmonitorschangesinwater demands through land usechanges and determines additional signposts together with water boards (water managers of the regionalsystem)andrepresentativesoftheagriculturalsector.

5. Evaluationofthemethod

Inthispaper,wehavepresentedanapproachforsupporting decisionmaking under uncertain global and regional changes, calledDynamicAdaptivePolicyPathways.Thisapproachassistsin designing dynamic adaptive plans, and is built upon the best featuresoftwoexistingadaptationmethods.Fromtheconceptof Adaptive Policymaking we used the ideas of (1) thinking beforehand of waysa plan might fail and designing actions to guardagainstsuchfailures,(2)preparingforactionsthatmightbe triggered later,in order tokeepa plan on track tomeetingits objectives,and(3)implementingamonitoringsystemtoidentify whensuchactionsshouldbetriggered.FromAdaptationPathways, weusedtheideaofanAdaptationPathwaysmap,whichvisualizes sequences of possible actions through time, and includes uncertainties concerning societal values through perspectives.

Themap is enrichedwithtriggersfromAdaptivePolicymaking, whichindicatewheneachnewactionshouldcomeintoforce.

Weillustratedtheintegratedapproachbyapplyingittoacase inspired bya realstrategy development project toprepare the Dutchwatersystemforfutureclimatechangetakingintoaccount socio-economicdevelopments.Byapplyingourapproachtoareal worldcase,wehavelearnedaboutthestrengthsandweaknessesof theapproach,whichweelaborateinthissection.

A strength of the method is that it stimulates planners to includeadaptationovertime intheirplans–toexplicitly think aboutactionsthatmayneedtobetakennowtokeepoptionsopen, anddecisionsthatcanbepostponed.Thus,theinevitablechanges becomepartofalarger,recognizedprocessandarenotforcedtobe maderepeatedlyonanadhocbasis.Planners,throughmonitoring and corrective actions, would try to keep the system headed towardtheoriginalgoals.

The concept of Dynamic Adaptive Policy Pathways may be difficulttounderstand.But,thetenclearlydefinedstepsdescribed inSection3provideasetofcleartasksthat,iffollowed,resultina dynamicadaptiveplan.Wehavediscussedthemethodwithwater and spatial planning policy advisors and policymakers in the Netherlandsatboththenationalandregional/locallevels.Onthe onehand,theapproachiscomprehensiveandmorecomplexthan a traditional scenario-strategy impact analysis for one or two pointsinthefuture.Ontheotherhand,plannershaveexperienced that plans change over time, and an adaptive strategy is an attractiveideaforplannersfacingdeepuncertainty.Moreover,if political conditionsareunsuitable,theapproach helpsto deter-mineforhowlongadecisioncanbepostponed.Thus,despitethe complexity,bothpolicyadvisorsandpolicymakershaveshownan interest inthemethod(see e.g.EEA,forthcomingin2013). The adaptationpathwayspresentedinthe‘metromap’andthetriggers and signposts are considered particularly valuable, as these components of the method are the main new characteristics comparedtoclassicalpolicyplanningapproaches.Foradiscussion withhighleveldecisionmakersasimplifiedpathwaysmap,based onpreferredpathways,couldbeusedincombinationwithamore comprehensive map as background information. The case pre-sented here has served as an inspiration for the Dutch Delta Programme, and is included in their implementation guide for ‘adaptivedeltamanagement’(vanRhee,2012).Currently, adapta-tion pathwaysare beingdeveloped for freshwater supply and flood riskmanagement. Newmodel resultsshowthatwiththe pathwayspresentedhere,anacceptablewatershortagemayoccur oncein100years,andthatforatargetofoncein10yearsthe sell-bydatesarefurtheraway(e.g.currentplanmaybesufficientfor achieving objectivesforapproximately 50years if thetarget is sufficientwaterforoncein10years).

Themomentofanadaptationtippingpoint(thesell-bydate) helpsinidentifyingpossiblepaths.However,mostactionscannot beimplementedimmediatelyattheirsell-bydate.Forthose,we needtoincludealeadtime.Thethinkingbehindtriggershelpsin identifyingrequiredleadtimes.However,climatechangemaybe difficult todetect, especially changes in extremes,due tolarge naturalvariabilitycomparedtothemagnitudeofchange(seee.g.

Diermanse et al., 2010; Hallegatte, 2009; Pielke, 2012). For

example,watermanagerswouldliketoknowifclimatechange is happening because of the potential increase of floods and droughts.However,measuring(forexample)peakdischargesasa signthatclimatechangeishappeningisverydifficult,becauseof highnaturalvariabilityandtheshorttimeperiodofmeasurements (Diermanseetal.,2010).Still,landuse,populationchanges,andsea levelrisearegradualdevelopmentsthatareeasiertodetect.

Withrespecttodecisionmaking,AdaptationPathwaysprovide insights intooptions,lock-ins,and pathdependencies.Thus, an AdaptationPathwaysmapprovidesa valuablestartingpointfor

decisionmakingonshort-termactions,whilekeepingoptionsopen andavoidinglock-ins.Allpathwayssatisfyaminimumperformance levelregardingthemain targets.Still,some pathwaysaremore attractivethanothersduetocostsornegative/positivesideeffects. Thiscanbeusedtoselect asetofpreferredpathways.Potential futuredecisivemomentscanbeidentifiedbasedontheleadtimeof actionsandthepointswherepreferredpathwaysstarttodiffer.

Todeterminethesuccessofactionsandpathways,quantitative targetsareneeded.However,inreality,policymakerssometimes choosetokeepthesetargetsvague,makingitdifficulttodetermine the efficacy of an action and pathway. Exploring different quantificationsofthetargetscanshowtheeffectsofthedifferent targets,whichmaysupportadiscussionaboutappropriatetargets. Aworthwhileelaborationontheapproachpresentedherewould betheevaluationofpathwayswith,e.g.acost–benefitanalysisora multi-criteriaanalysis.

The visualization of the pathways is seen as attractive by policymakers.Thiswayofvisualizingworksbestiftheobjectives canbesummarizedinasinglemainobjective,suchas‘freshwater supplyfordifferentsectors’or‘safetyagainstflooding’.Inourcase, weconsidered two main objectivesthat influenced eachother. Because theflood management actions didnot vary a lot, the relationbetweenthetwosetsofactionscouldbeeasilydescribed. IntheDutchDeltaProgrammethesituationismorecomplexdue toplanningfordifferentareasthathavedifferentpathwaysthat influenceeachother.

The use of perspectives is an element that has previously received little attention in the planning literature. We used differentperspectives(orvisions)ofthedifferentstakeholdersto identifyalternativepreferredpathwaysandsociallyrobustactions (Offermansetal.,2008,2011).Differentstakeholdersmaysupport differentplans,buttheycanalsohavedifferentreasonstosupport thesameplan.Forexample,allocating‘roomforariver’maybe preferredbysomebecauseitenhancesnatureandlowerswater levelsinthecaseofpeakdischarges,whileothersmaypreferthis action solely becauseit lowers theflood risk. Development of pathways using stakeholder participation (decisionmakers and stakeholders)hasbeenexploredinagamesetting(Valkeringetal., 2012).Inthisway,uncertaintiesarisingfromdecisionmaking,and preferencesamongplansarisingfromdifferentperspectives,can befurtherexplored.

Theanalyticalbasisoftheapproach(e.g.fordeterminingsell-by datesanddevelopingpathways)canbesupportedwith computa-tionalscenario-basedapproaches.Makingthenecessaryrunsina reasonableamountoftimerequiresapolicymodelthatisfastand simple, but accurate enough tosimulate the relevanttransient scenariosand assessthe relativeeffects froma wide varietyof actions for the full set of performance indicators over time. Currently, there is no such model of the lower Rhine Delta. Therefore,weassessed theeffectivenessandsell-bydatesofthe possibleactions using expert judgment andmodel results from previous studies. We were able to assess the relative impacts qualitatively. McDaniels et al. (2012) used expert judgment to explorerobustalternatives.But,forabetterdeterminationofthe sell-bydates,acomputationalexplorationiscrucial.Thereisaneed forfastsimplemodelsthataresuitableforexploringactionsover time in order to develop adaptation pathways. More complex modelscanthenbeusedtoobtainmoredetailedinformationabout theperformanceofthemostpromisingactionsresultingfromthe initialexploration.

Furtherworkisalsoneededoncomputationaltechniquesthat can help in identifying opportunities and vulnerabilities and developingpromisingpathways.Inarealcase,thecombinationof actionsandconsequentlythenumberpathwayscanbehuge.To supportthe identification of themost promising sequences of actions, we are working on an improved computer-assisted

approachfordesigninganadaptivepolicytoevaluatecandidate pathwaysover anensembleofpossiblefuturesandassesstheir robustness(KwakkelandHaasnoot,2012).Lempertetal.(2006),

LempertandGroves,2010presentacomputerassistedapproachto developrobuststrategies acrossa varietyofdeepuncertainties, grounded in Exploratory Modeling and Analysis (Agusdinata, 2008; Bankes, 1993; Bankeset al., 2013). We aredeveloping a ‘workbench’ to support such computational scenario-based techniques.Earlyexperienceswiththeworkbenchindicatethat usingafastandsimplemodel,exploringuncertaintiesinaddition toclimatechange,andaccountingforthejointimpactofallthe uncertainties, in support of the development of adaptation pathwaysisusefulandfeasible(KwakkelandHaasnoot,2012).

6. Concludingremarks

In light of the deepuncertainties decisionmakers are facing nowadays,anewplanningapproachisneededthatresultsinplans thatperformsatisfactorilyunderawidevarietyoffuturesandcan beadaptedovertimeto(unforeseen)futureconditions.Various techniques are available (e.g. Robust Decision Making, Real Options Analysis, decision trees, roadmaps, and several policy planning approaches) that have been or are being appliedfor supportingplanningunderdeepuncertainty(e.g.intheThames EstuaryintheUK,theRhine-MeusedeltaintheNetherlands,and NewYorkCityandthePortofLosAngelesintheUSA).Wehave used two complementaryapproaches for planning under deep uncertainty—AdaptivePolicymakingandAdaptationPathways— todevelopanintegratedapproachbasedonthestrongfeaturesof each of them. This approach, called Dynamic Adaptive Policy Pathways, resultsin anadaptive plan that is abletodeal with changing(unforeseen)conditions.

Key principles of the Dynamic Adaptive Policy Pathways approachare:theuseoftransientscenariosrepresentingavariety of relevant uncertainties and their development over time; anticipatingand correctiveactionstohandlevulnerabilitiesand opportunities;severalAdaptationPathwaysdescribingsequences ofpromisingactions;andamonitoringsystemwithrelatedactions tokeeptheplanonthetrackofapreferredpathway.Theapproach supportstheexplorationofawidevarietyofrelevantuncertainties in a dynamic way, connectsshort-term targets and long-term goals, and identifies short-term actions while keeping options open for the future. There is evidence that such policies are efficacious(Kwakkeletal.,2012)andcost-beneficial(Yzeretal., submitted).Intheend,allthishastofitintoapoliticalprocess, whichhasalwaysbeenarealsourceof‘deepuncertainty’.Political circumstances can give a window of opportunity (or not) to implement thedesigned adaptive plan. Also, theadaptive plan could be used to create the right political circumstances, for examplebyshowingpotentiallock-ins,potentialadverseimpacts, andforhowlongadecisioncanbepostponed.ThePerspectives method couldbe used to frame the plan for different societal perspectives(asillustratedbyOffermansetal.,2008).

Inthispaper,wehaveillustratedandtestedtheapproachusing avirtualworldinspiredbyarealworlddecisionproblemcurrently facedbytheDutchNationalGovernmentintheDeltaProgramme. Wewereabletoapplythemethod,andthisresultwasreceived withgreatinterestbypolicymakersoftheDutchDeltaProgramme. Theresultssuggestthatitisworthwhiletofurtheruseandtestthe approachforarealquantitativecasestudy,otherpolicydomains, andothercountries.

Acknowledgments

ThisresearchhasbeenfundedbytheDeltaresresearchproject ‘PerspectivesinIntegratedResourcesManagementinRiverdeltas’and

the ‘Knowledge for Climate’ Research Programme, under the researchtheme‘ClimateProofFreshWaterSupply’.Wewouldliketo thankourcolleaguesworkingontheDeltaProgramme(especially PieterBloemen,AdJeuken,NathalieAsselmanandFransKlijn)for theirfeedbackontheapproach.Wealsothankthereviewersfor theirusefulsuggestionsonanearlierversionofthepaper.

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