HydroGem³ – meteo

Hydrological scenarios for two selected Alpine catchments for the next century using a statistical weather generator and enhanced process understanding for modelling of seasonal snow and glacier melt for improved water resources management
The overall objective of the present project is to assess water demand and supply in a coupled human environment mountain system, with a special emphasis on the analysis of possible future seasonal water scarcity. The hydrological response of high Alpine catchments is characterised by a strong seasonal variability with low runoff in winter and high runoff in spring and summer. Climate change is expected to lead to a seasonal shift of the runoff regime and thereby has a significant impact on timing and amount of the available water resources.

The contribution of the meteorological part to this project is to provide current and future meteorological forcing for the hydrological modelling until the end of the century using a statistical weather generator. Specifically, due to the needs for hydrological modelling at small scales, a single-site (standard) weather generator will be extended to multi-site functionality. EUROCORDEX data will be used as input for the scenario calculations.

In order to identify possible future water conflicts in two selected mountain catchments (Ötztal catchment in Austria and Lütschine catchment in Switzerland ), the contribution of snowmelt and ice melt, as well as rain is assessed. Streamflow composition will be analysed with natural tracers for determining its components, such as (i) snowmelt, (ii) ice melt, and (iii) rain. The results of the field investigations help to improve the snow- and ice melt and runoff modules of two selected hydrological models (i.e. AMUNDSEN and WaSiM). These models are used to investigate the seasonal water availability in the two selected catchments under current and future climate conditions. Together, they comprise improved descriptions of the boundary layer and surface melt processes (AMUNDSEN), and of streamflow runoff generation (WaSiM).

Eventually, the comparison of water availability and water demand under current and future climate conditions allows the identification of possible seasonal bottlenecks in the future water supply. These results might provide the quantitative basis for the development of sustainable strategies for mountain societies in improving their skills to cope with modified flow regimes.

Collaboration

• Prof. Dr. Ulrich Strasser (Institute of Geography, UIBK)
• Dr. Martin Dubrovsky (Institute of Atmospheric Physics, Czech Academy of Sciences)
• Prof. Dr. Michael Obberguggenberger (Technical Mathematics, UIBK)

Project

Project Leader:Mathias ROTACH

Members:Hetal DABHI

Funding Agencies:
ÖAW

Project Duration:
01/06/2015 to 31/12/2019