River runoff in Switzerland in a changing climate – runoff regime changes and their time of emergence

Abstract. Assessments of climate change impacts on runoff regimes are essential to adaptation and mitigation planning. Changing thus changing seasonal patterns water availability strongly influence various economic sectors such as agriculture, energy production, fishery also affect river ecology. In this study, we use new transient hydrological scenarios driven by the most up-to-date local projections for Switzerland, Swiss Climate Change Scenarios. These provide detailed information changes in their time emergence 93 rivers Switzerland under three Representative Concentration Pathways (RCPs): RCP2.6, RCP4.5, RCP8.5. allow be framed a function global mean temperature. The largely confirm sign from previous with increasing winter decreasing summer autumn runoff. Spring is projected increase high-elevation catchments decrease lower-lying catchments. Despite increases some spring, annual Compared catchments, (above 1500 m a.s.l.) larger winter, due large reduced snow accumulation earlier snowmelt glacier melt. agreement between models both temperatures higher-emission scenarios. This amplification highlights importance mitigation. when signal emerges significantly natural variability. Under RCP8.5, times were found early, before period 2036–2065, altitudes above a.s.l. Significant below emerge later century. Not all show significant distribution means; thus, no could determined these Furthermore, not persistent over nonlinear