Assessment of climate‐change impacts on alpine discharge regimes with climate model uncertainty

• DOI: 10.1002/hyp.6197
• Publication Date: 2006-06-08T16:34:08Z
• Authors: Pascal Horton; Bettina Schaefli; Abdelkader Mezghani; Benoît Hingray; André Musy
• Keywords: HadCM3; Snowmelt; Meltwater; Transient climate simulation

Abstract This study analyses the uncertainty induced by use of different state‐of‐the‐art climate models on prediction climate‐change impacts runoff regimes 11 mountainous catchments in Swiss Alps having current proportions glacier cover between 0 and 50%. The scenarios analysed are result 19 regional model (RCM) runs obtained for period 2070–2099 based two greenhouse‐gas emission (the A2 B2 defined Intergovernmental Panel Climate Change) three coupled atmosphere‐ocean general circulation (AOGCMs), namely HadCM3, ECHAM4/OPYC3 ARPEGE/OPA. hydrological response to is simulated through a conceptual reservoir‐based precipitation‐runoff transformation called GSM‐SOCONT. For glacierized catchments, surface corresponding these future updated evolution model. results show that all induce, an earlier start snowmelt period, leading shift maximum monthly discharges. mean annual decreases significantly most cases. regime modifications mainly due increase temperature snow accumulation melting processes. located at lower altitudes more strongly affected changes seasonal precipitation. given scenario, highly variable RCM runs. variability driving AOGCM, but also large part inter‐RCM variability. differences so important predicted overlapping. Copyright © 2006 John Wiley & Sons, Ltd.