Trends in the hydrologic regime of Alpine rivers

Research output: Contribution to journalArticlepeer-review

Authors

  • Antoine Bard
  • Benjamin Renard
  • Michel Lang
  • Jane Korck
  • Gernot Koboltschnig
  • Mitja Janža
  • Michele D’amico
  • David Volken

Colleges, School and Institutes

Abstract

This paper describes a trend analysis performed on 177 streamflow time series collected over the Alps in Central Europe. The analysis covers several facets of the Alpine hydrologic regimes, including winter droughts and spring snowmelt flows, both in terms of severity and timing of occurrence. Statistical trend tests are applied at a local scale (i.e. on a site-by-site basis) and at a regional scale (seeking a common trend for sites within the same hydro-climatic region). The overall results indicate a trend toward less severe winter droughts, and consistent changes in the timing of snowmelt flows. However, a more in-depth analysis at the scale of hydro-climatic regimes reveals more contrasted changes. While most glacial- and snowmelt-dominated regimes show a decreasing trend in the severity of winter droughts, contrasted trends are found for mixed snowmelt–rainfall regimes in the Southeastern Alps. Changes in the timing of snowmelt flows (earlier start and increased duration of the snowmelt season) mostly affect glacial- and snowmelt-dominated regimes. Lastly, glacial regimes show an increase in the volume and the peak of snowmelt flows.

Details

Original languageEnglish
JournalJournal of Hydrology
Early online date18 Aug 2015
Publication statusE-pub ahead of print - 18 Aug 2015

Keywords

  • Streamflow, Trend analysis, Alps, Snowmelt, Droughts, Spring onset