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 hydro-graph 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

The impacts of climate change on river flood risk at the global scale

“…Pappenberger et al 2012) may give different indications of regional exposure to flood risk. Dankers et al (2013) show how projected changes in flood magnitudes can vary considerably between different global hydrological models, largely due to their different representation of evaporation and snowmelt processes. New attempts to estimate current global flood risk (e.g.…”

“…Bell et al 2007;Prudhomme et al 2003;Milly et al 2002;Lehner et al 2006;Hirabayashi et al 2008;Dankers and Feyen 2009;Dankers et al 2013). A key conclusion of such studies is that the projected effects of climate change on the flood hazard may be very substantial, but are very dependent on climate scenario.…”

Assessments of joint hydrological extreme risks in a warming climate in China

“…In this article, the climate projections are bias corrected against observations (Hempel et al, 2013), and the value of them has also been well demonstrated in a number of recent studies (e.g. Dankers et al, 2014;Elliott et al, 2014;Haddeland et al, 2014;Leng and Tang, 2014;Piontek et al, 2014;Prudhomme et al, 2014;Schewe et al, 2014). Moreover, the impact model (i.e.…”

“…drought/floods) have applied the so-called fixed threshold method (e.g. Hirabayashi et al, 2013;Dankers et al, 2014;Prudhomme et al, 2014). Typically, characteristics of extremes in the 21st century are identified by using the threshold derived from the fixed historical period (e.g.…”

Improving Flood Prediction Assimilating Uncertain Crowdsourced Data into Hydrological and Hydraulic Models

“…In the last decades, the impact of floods has drastically increased worldwide (European Environment Agency, 2006;Di Baldassarre et al, 2010;Aerts et al, 2014;Dankers et al, 2014). Flood events in Europe, such as the 2002 Elbe floods and the 2007 UK floods, are considered national crises and are estimated to have caused around 15 and 6.5 billion Euro of damage respectively (European Environment Agency, 2006).…”