Seite - 300 - in Loss and Damage from Climate Change - Concepts, Methods and Policy Options

300 W.J.WouterBotzenet al. be based on three factors: (1) the probability of individual fatalities due to flooding, (2) theprobabilityof largenumbersof simultaneouscasualties, and (3) economicand other damage (to landscape, to natural and cultural heritage values, to the country’s reputation and to society).Toachieve this aim, the committee tentatively advised that protection levels for all dike rings should be increased by a factor of ten (e.g., if the currentprotection levelwas1/1,000, it shouldbe increased to1/10,000). Acost-benefit analysis to determine optimal protection standards for all dike rings in theNetherlandswasinitiatedbytheCBPBureauforEconomicPolicyAnalysisin2005 (Eijgenraam et al. 2014). This analysis determined the optimal protection level for a dike ringas thatprotection levelwhere themarginalprotectioncostswouldequate the marginal avoided damages.Damages included direct and indirect economic damage, andlossof lifeexpressedinmonetaryvalue throughthevalueofstatistical lifeconcept (Bockarjovaetal.2012).Withthisapproach,optimalprotectionlevelsweredetermined for all dike rings in the Netherlands (Kind 2014). It is interesting to note that the investmentcostsoftheeconomicallyefficientfloodprotectionstandardswereestimated tobee7.8billion: almost 70%cheaper than the investment costs associatedwith the adviceof the secondDeltaCommittee to increaseprotection standardseverywhereby a factor of ten (Eijgenraamet al. 2014).TheDeltaCommissioner, appointed in2010, developedfloodprotectionstandardsupto theyear2050andtakes thepotentialeffects ofclimatechangeonsealevelriseandriverdischargeintoaccount.Anumberofclimate andsocioeconomicscenarioshavebeenexplored foruse in theDeltaProgramme.The underlying climate scenarios were developed by the DutchMeteorological Institute KNMI. In the scenario withmost climate change, regional sea level rise in 2050 is 35cm,increasingto85cmin2100.Forfutureriverdischarge,floodprotectionpolicies in upstream countries are relevant. Themaximum river discharge of the river Rhine in theNetherlands is presently ‘capped’ at 16,500m3/s, because higher discharge is made impossiblebyflooding thatwouldoccurupstreaminGermany.Due to increases in the likelihood of extremeprecipitation events, themaximumdischarge is assumed to increase to17,000m3/s in2050and18,000m3/s in2100.Similarcalculationshave beenmadefor theriverMeuse.TheDeltaProgrammeadvocatesadaptivemanagement (’adaptive deltamanagement’) to address future uncertainties, including the impacts of climate change, in a transparent manner. The Delta Commissioner combined the CPBeconomicassessmentwiththeotherfactors thathadbeensuggestedbythesecond Delta committee, In the first place, the standards should offer a commonminimum levelofprotection for eachcitizen tobeprotectedbydikesordunesby theyear2050. Secondly,higherstandardsareofferedinlocationswherethereisariskoflargenumbers of victims, or of serious damage to vital infrastructure of national importance, or of high economic damage, as indicated byCPB’s economic assessment. The newflood protectionstandardswerepresentedtoandadoptedbyParliamentin2014.SourceKuik et al. (2016)