title: First look at changes in flood hazard in the Inter-Sectoral Impact Model Intercomparison Project ensemble.
abstract: Climate change due to anthropogenic greenhouse gas emissions is expected to increase the frequency and intensity of precipitation events, which is likely to affect the probability of flooding into the future. In this paper we use river flow simulations from nine global hydrology and land surface models to explore uncertainties in the potential impacts of climate change on flood hazard at global scale. As an indicator of flood hazard we looked at changes in the 30-y return level of 5-d average peak flows under representative concentration pathway RCP8.5 at the end of this century. Not everywhere does climate change result in an increase in flood hazard: decreases in the magnitude and frequency of the 30-y return level of river flow occur at roughly one-third (20-45%) of the global land grid points, particularly in areas where the hydrograph is dominated by the snowmelt flood peak in spring. In most model experiments, however, an increase in flooding frequency was found in more than half of the grid points. The current 30-y flood peak is projected to occur in more than 1 in 5 y across 5-30% of land grid points. The large-scale patterns of change are remarkably consistent among impact models and even the driving climate models, but at local scale and in individual river basins there can be disagreement even on the sign of change, indicating large modeling uncertainty which needs to be taken into account in local adaptation studies.
authors.affiliation: Met Office Hadley Centre, Exeter EX1 3PB, United Kingdom.
authors.forename: Rutger
authors.initials: R
authors.lastname: Dankers
authors.forename: Nigel W
authors.initials: NW
authors.lastname: Arnell
authors.forename: Douglas B
authors.initials: DB
authors.lastname: Clark
authors.forename: Pete D
authors.initials: PD
authors.lastname: Falloon
authors.forename: Balázs M
authors.initials: BM
authors.lastname: Fekete
authors.forename: Simon N
authors.initials: SN
authors.lastname: Gosling
authors.forename: Jens
authors.initials: J
authors.lastname: Heinke
authors.forename: Hyungjun
authors.initials: H
authors.lastname: Kim
authors.forename: Yoshimitsu
authors.initials: Y
authors.lastname: Masaki
authors.forename: Yusuke
authors.initials: Y
authors.lastname: Satoh
authors.forename: Tobias
authors.initials: T
authors.lastname: Stacke
authors.forename: Yoshihide
authors.initials: Y
authors.lastname: Wada
authors.forename: Dominik
authors.initials: D
authors.lastname: Wisser
mesh_terms: D057231:Climate Change; D003198:Computer Simulation; D055868:Floods / Q000706:statistics & numerical data*; D005544:Forecasting; D057446:Hydrodynamics; D008962:Models, Theoretical; D045483:Rivers
keywords: climate impacts; extremes; river flows