Aqueduct Floods: Flood Protection Dr. Philip Ward (Institute for Environmental Studies, VU University Amsterdam) Setup 1. Flood risk assessment model 2. Framework for estimating costs and benefits of dikes • Developing national 3. FloodResults Risk using Management first model framework implementation Plan for Nigeria • To develop resilience to floods, following recommendations from PDNA after 2012 floods Flood risk The elements (e.g. buildings, The threatening event The resistance or lack of humans, economic values) (including its probability and resistance of the exposed present in the area affected geographical extent) elements to the hazard Current flood risk: GLOFRIS Hazard Inundation depth (50 yr return period) Damage per Expected return period Annual Damage (EAD) Vulnerability $ $/yr Value of assets Exposure Ward et al., 2013. Environmental Research Letters, doi:10.1088/1748-9326/8/4/044019 Winsemius et al., 2013. Hydrology and Earth System Sciences, doi:10.5194/hess-17-1871-2013 Setup 1. Flood risk assessment model 2. Framework for estimating costs and benefits of dikes • Developing national 3. FloodResults Risk using Management first model framework implementation Plan for Nigeria • To develop resilience to floods, following recommendations from PDNA after 2012 floods FLOPROS: global flood protection standards database Scussolini et al., 2016. NHESS, doi:10.5194/nhess- 16-1049-2016 Costs and benefits: benefits B = EADnoadapt - EADadapt • Developing national Flood Risk Management implementation Plan for Nigeria • To develop resilience to floods, following recommendations from PDNA after 2012 floods Costs and benefits: costs C = (DikeHeightadapt – DikeHeightbaseline) X Cost of dike (USD.km.m) X • Developing national Flood Risk Management Length of dike required implementation Plan for Nigeria • To develop resilience(+ to maintenance costs of x% p.a.) floods, following recommendations from PDNA after 2012 floods Costs and benefits: costs C = (DikeHeightadapt – DikeHeightbaseline) X Cost of dike (USD.km.m) X • Developing national Flood Risk Management Length of dike required implementation Plan for Nigeria • To develop resilience(+ to maintenance costs of x% p.a.) floods, following recommendations from PDNA after 2012 floods Costs and benefits: costs C = (DikeHeightadapt – DikeHeightbaseline) X Cost of dike (USD.km.m) X • Developing national Flood Risk Management Length of dike required implementation Plan for Nigeria • To develop resilience(+ to maintenance costs of x% p.a.) floods, following recommendations from PDNA after 2012 floods Costs and benefits: costs C = (DikeHeightadapt – DikeHeightbaseline) X Cost of dike (USD.km.m) X • Developing national Flood Risk Management Length of dike required implementation Plan for Nigeria • To develop resilience(+ to maintenance costs of x% p.a.) floods, following recommendations from PDNA after 2012 floods Costs and benefits: costs C = (DikeHeightadapt – DikeHeightbaseline) X Cost of dike (USD.km.m) X • Developing national Flood Risk Management Length of dike required implementation Plan for Nigeria • To develop resilience(+ to maintenance costs of x% p.a.) floods, following recommendations from PDNA after 2012 floods Setup 1. Flood risk assessment model 2. Framework for estimating costs and benefits of dikes • Developing national 3. FloodResults Risk using Management first model framework implementation Plan for Nigeria • To develop resilience to floods, following recommendations from PDNA after 2012 floods Research questions 1. What protection standards are required to keep future flood risk constant? And what are the associated costs and benefits? 2. What protection standards maximize the net present value (NPV) of the investment? Example: Oregon Best-estimate protection standard Return period = 60 years Current EAD: USD0.9 billion p.a. EAD future = EAD current (Business as Usual; RCP8.5/SSP2) EAD future = EAD current (Business as Usual; RCP8.5/SSP2) EAD future = EAD current (Business as Usual; RCP8.5/SSP2) USD0.9 billion p.a. EAD future = EAD current (Business as Usual; RCP8.5/SSP2) Current and future flood protection standards a) RCP2.6/SSP1 (‘Sustainability’) b) RCP4.5/SSP2 (‘Middle of the Road’) c) RCP6.0/SSP3 (‘Fragmented world’) d) RCP8.5/SSP5 (‘Fossil-fuel based’) Costs and benefits at global scale Sustainability Middle of the Road Fragmented world Fossil-fuel based RCP2.6/SSP1 RCP4.5/SSP2 RCP6.0/SSP3 RCP8.5/SSP5 Maintain constant Expected Annual Damage Benefits (USD billion p.a.) 339 276 125 827 Costs (USD billion p.a.) 170 177 155 219 B:C ratio 2.0 1.6 0.8 3.8 Net present value (USD billion) 169 99 -30 608 • All values in USD 2005 (PPP) • Costs and benefits accumulated until 2100 • Average results over 5 GCMs • 5% discount rate, 1% maintenance costs per year Ward et al., 2017. Nature Climate Change, doi:10.1038/nclimate3350 Costs and benefits at global scale Sustainability Middle of the Road Fragmented world Fossil-fuel based RCP2.6/SSP1 RCP4.5/SSP2 RCP6.0/SSP3 RCP8.5/SSP5 Maintain constant Expected Annual Damage Benefits (USD billion p.a.) 339 276 125 827 Costs (USD billion p.a.) 170 177 155 219 B:C ratio 2.0 1.6 0.8 3.8 Net present value (USD billion) 169 99 -30 608 • All values in USD 2005 (PPP) • Costs and benefits accumulated until 2100 • Average results over 5 GCMs • 5% discount rate, 1% maintenance costs per year Ward et al., 2017. Nature Climate Change, doi:10.1038/nclimate3350 Costs and benefits at global scale Sustainability Middle of the Road Fragmented world Fossil-fuel based RCP2.6/SSP1 RCP4.5/SSP2 RCP6.0/SSP3 RCP8.5/SSP5 Maintain constant Expected Annual Damage Benefits (USD billion p.a.) 339 276 125 827 Costs (USD billion p.a.) 170 177 155 219 B:C ratio 2.0 1.6 0.8 3.8 Net present value (USD billion) 169 99 -30 608 Maintain constant Expected Annual Damage as a percentage of GDP Benefits (USD billion p.a.) 275 225 100 721 Costs (USD billion p.a.) 73 80 76 108 B:C ratio 3.8 2.8 1.3 6.7 Net present value (USD billion) 202 145 24 613 • All values in USD 2005 (PPP) • Costs and benefits accumulated until 2100 • Average results over 5 GCMs • 5% discount rate, 1% maintenance costs per year Ward et al., 2017. Nature Climate Change, doi:10.1038/nclimate3350 Benefit:Cost ratios per state a) RCP2.6/SSP1 (‘Sustainability’) b) RCP4.5/SSP2 (‘Middle of the Road’) c) RCP6.0/SSP3 (‘Fragmented world’) d) RCP8.5/SSP5 (‘Fossil-fuel based’) Ward et al., 2017. Nature Climate Change, doi:10.1038/nclimate3350 Research questions 1. What protection standards are required to keep future flood risk constant? And what are the associated costs and benefits? 2. What protection standards maximize the net present value (NPV) of the investment? Return periods of protection with highest NPV a) RCP2.6/SSP1 (‘Sustainability’) b) RCP4.5/SSP2 (‘Middle of the Road’) c) RCP6.0/SSP3 (‘Fragmented world’) d) RCP8.5/SSP5 (‘Fossil-fuel based’) Ward et al., 2017. Nature Climate Change, doi:10.1038/nclimate3350 Next steps 1. Coastal flood risk 2. Costs and benefits of coastal adaptation • Developing national 3. FloodMore Risk adaptation Management strategies implementation Plan for Nigeria 4. User testing • To develop resilience to floods, following recommendations from PDNA after 2012 floods Thank you! Gracias Artwork: © www.henkdeboer.nl Questions: [email protected].