Glacier melt and runoff: from the local to the continental scale
Event details
| Date | 04.12.2012 |
| Hour | 16:15 › 17:15 |
| Speaker | Dr Matthias Huss, senior lecturer, Université de Fribourg, Unité de Géographie |
| Location | |
| Category | Conferences - Seminars |
Glaciers are excellent indicators for climatic changes and have strongly retreated over the last decades in the European Alps, as well as worldwide. Glacial melt water importantly contributes to discharge in alpine drainage basins but also at over-regional scales. Changes in future melt water yield by glacier-fed streams will have important impacts on water availability and hydropower production in mountainous regions. In this seminar, the whole process chain from glacier response to climate change to both the local and continental scale importance of glaciers to runoff will be covered.
Various long-term data sets from the Swiss Alps allow investigating the driving forcing factors, as well as the dynamics of glacier retreat over the last century. Glaciers in the European Alps have lost an ice volume of about 100 km3 since 1900 which almost equals their present volume. This additional melt water released from long-term glacial storage is currently enhancing flow from alpine catchments. Many important feedback mechanisms drive the observed glacier retreat and need to be included in impact models in order to reliably simulate future changes. Physical models accounting for glacier surface mass balance, ice flow and runoff generation have been run over the entire 21st century using climate scenarios. Glaciers in the Alps are expected to be reduced to 4-18% of their current size by 2100. The scenarios indicate a transient increase in runoff peaking between 2010 and 2060, depending on the characteristics of the catchments, and an important shift in the hydrological regime towards less runoff in the summer months.
By comparing monthly glacier storage changes that were calculated using a model constrained with different types of long-term field data over the period 1900-2100 to observed runoff in Europe’s large streams, the percental contribution of glaciers to runoff is analyzed and discussed. These macroscale drainage basins with a size of 100’000 km2 can show a glacier contribution to runoff up to 25% in the month of August as a mean over the last century.
Various long-term data sets from the Swiss Alps allow investigating the driving forcing factors, as well as the dynamics of glacier retreat over the last century. Glaciers in the European Alps have lost an ice volume of about 100 km3 since 1900 which almost equals their present volume. This additional melt water released from long-term glacial storage is currently enhancing flow from alpine catchments. Many important feedback mechanisms drive the observed glacier retreat and need to be included in impact models in order to reliably simulate future changes. Physical models accounting for glacier surface mass balance, ice flow and runoff generation have been run over the entire 21st century using climate scenarios. Glaciers in the Alps are expected to be reduced to 4-18% of their current size by 2100. The scenarios indicate a transient increase in runoff peaking between 2010 and 2060, depending on the characteristics of the catchments, and an important shift in the hydrological regime towards less runoff in the summer months.
By comparing monthly glacier storage changes that were calculated using a model constrained with different types of long-term field data over the period 1900-2100 to observed runoff in Europe’s large streams, the percental contribution of glaciers to runoff is analyzed and discussed. These macroscale drainage basins with a size of 100’000 km2 can show a glacier contribution to runoff up to 25% in the month of August as a mean over the last century.
Practical information
- General public
- Free
- This event is internal
Organizer
- IIE
Contact
- Dr Bettina Schaefli, FNS Ambizione @ECHO