The Austrian Alps are experiencing rapid warming, and this leads to severe changes in meteorological and hydrological conditions. Snow cover is changing, with direct implications for river discharge in mountainous regions and downstream areas. Furthermore, soil water content and storage are changing due to increased temperature and changing precipitation patterns, leading to extremely wet or dry conditions and related flood and landslide and drought hazard. To mitigate and adapt to changing conditions, accurate observations and predictions of hydrological conditions over Alpine regions is pivotal. This is particularly valid for Austria, where the Alps are not only valuable ecosystems, but also play a crucial role in sectors such as water supply, electricity production, agriculture, tourism and industry.
To analyse and test climate scenarios in support of climate adaptation and decision making, ECMWF will introduce the Climate Change Adaptation Digital Twin (ClimateDT) with an unprecedented resolution of 5 km. The goal of the Digital Twin Austria - Alpine Hydrology and Future Hazards project is to use the ClimateDT and Copernicus Earth Observation (EO) data to assess current and future hydrological hazards over the Austrian Alps. We will extend the Earth Observation Data Centre’s (EODC) Austrian Datacube (ACube) with the ClimateDT and Copernicus EO-based snow cover extent and soil moisture products tailored to the Alps. A data pipeline to extract all relevant ClimateDT variables from the Destination Earth Data Lake (DEDL) will be developed utilising data proximate computing by EODC. The EO-based snow cover extent product will be processed for Austria for the time period covering the Destination Earth Service Platform (DESP) period, and gap-filled with a novel approach using precipitation and temperature fields data in a physically based snowpack model. The EO-based surface soil moisture product will be improved for complex terrain, using radiometrically terrain flattened gamma naught backscatter as input. Furthermore, surface and root zone soil moisture will be retrieved. Using in situ data and Copernicus EO-based soil moisture and snow products and Geosphere Austria SPARTACUS precipitation and temperature as reference, TU Wien Remote Sensing (TUW RS) and ENVEO will validate and test the physical plausibility of the ClimateDT in a rigorous quality assurance. The added-value of the Copernicus-based products and ClimateDT will be demonstrated by TUW Hydrology group in hydrological modelling of streamflows over a large number of catchments in the Austrian Alps, using both ClimateDT and EO-based snow cover extent and soil moisture data. In addition, TUW RS will develop soil moisture drought indicators for Austria. Trends in future hydrological hazards, i.e. low flows, high flows and droughts, will be provided based on the hydrological modelling and drought indicators using ClimateDT. Project outcomes will be shared through the ACube and a dashboard designed for the project by EODC. In addition, project outcomes will be prepared for potential visualization through GTIF-AT. The project directly addresses ECMWF’s partner programme and will benefit Austrian stakeholders such as the hydrological service of Tirol, Austria Environmental Agency, Geosphere Austria and electricity company Verbund, who are supporting the project.
