Analysis of hydrological extremes at different hydro-climatic regimes under present and future conditions

Abstract

We investigate simulated hydrological extremes (i.e., high and low flows) under the present and future climatic conditions for five river basins worldwide: the Ganges, Lena, Niger, Rhine, and Tagus. Future projections are based on five GCMs and four emission scenarios. We analyse results from the HYPE, mHM, SWIM, VIC and WaterGAP3 hydrological models calibrated and validated to simulate each river. The use of different impact models and future projections allows for an assessment of the uncertainty of future impacts. The analysis of extremes is conducted for four different time horizons: reference (1981-2010), early-century (2006-2035), mid-century (2036-2065) and end-century (2070-2099). In addition, Sen's non-parametric estimator of slope is used to calculate the magnitude of trend in extremes, whose statistical significance is assessed by the Mann-Kendall test. Overall, the impact of climate change is more severe at the end of the century and particularly in dry regions. High flows are generally sensitive to changes in precipitation, however sensitivity varies between the basins. Finally, results show that conclusions in climate change impact Center for Global Change and Water Cycle, Hohai University, Nanjing, China studies can be highly influenced by uncertainty both in the climate and impact models, whilst the sensitivity to climate modelling uncertainty becoming greater than hydrological model uncertainty in the dry regions.

Sources of uncertainty in hydrological climate impact assessment: a cross-scale study

“…While a first set of hydrology-related publications described global scale impacts , Dankers et al 2014, Prudhomme et al 2014, Haddeland et al 2014, Davie et al 2013, Wada et al 2013and Portmann et al 2014, a second set of studies focused on impacts on the hydrological cycle, water resources, seasonality and extremes at the regional scale (e.g. Eisner et al 2017, Vetter et al 2017, Mishra et al 2017, Pechlivanidis et al 2017, Gelfan et al 2017, Teklesadik et al 2017and Su Buda et al 2017. Cross-scale studies using both, the outcomes of global and regional hydrological models, were published in Hattermann et al (2017) and Gosling et al (2017).…”

“…Climate impacts on seasonal dynamics and quantification of uncertainties, for example, can be found in Eisner et al (2017). Pechlivanidis et al (2017) reported that results are generally more uncertain in dry basins than in wet ones. This finding is supported by Samaniego et al (2017), who also discovered generally a higher contribution of hydrological model uncertainty to total uncertainty in projected droughts (although still being lower than the share of climate model uncertainty).…”

Multi-Source Uncertainty Analysis in Simulating Floodplain Inundation under Climate Change

“…The difference in the rather optimistic RCP 2.6 and the rather pessimistic RCP 8.5 is rather small compared to the differences arising from the selection of the GCM and the underlying uncertainties arising from the hydrological modeling. The future predictions of the Rhine river remains very uncertain compared to other large river basins world-wide [68].…”

Change in snow depletion pattern in a river basin of Arunachal Pradesh under projected climatic scenarios

“…The use of different scenarios allows for the estimation of uncertainty of future impacts (Pechlivanidis et al, 2015;2016a;2016b). The Intergovernmental Panel on Climate Change (IPCC) SRES (Nakicenovic and Swart, 2000) describes that projected scenarios are the product of very complex dynamic systems, determined by driving forces such as demographic development, socio-economic development, and technological change.…”