SCA4LISFLOOD

This six-months consultancy activity for the Joint Research Centre (JRC) aims to investigate the capabilities and constraints of the snow module within the LISFLOOD model in accurately representing snow water balances throughout Europe. To achieve this goal, the parameters of the snowmelt module implemented in LISFLOOD, specifically the annual average snowmelt coefficient, will be determined through a comparison with snow cover data obtained from satellite imagery. To this purpose, accurate daily snow cover extent time-series will be created for at least six important river basins around Europe. Information about snow cover depletion will be used to provide insights into the model's performance and highlight key issues that need to be addressed to achieve a sufficiently realistic snow water balance across Europe.

The work is divided into eight main activities. First, six river basins or subbasins will be identified, for which snow represents a relevant hydrological compartment. These will be generally mountain and Nordic regions across Europe, where snow cover is present for a sufficient number of days during the year. The selected watersheds should include important mountain ranges in Europe such as the Alps, the Pyrenees, the Carpathians, and the Apennines. A Nordic setting will also be included. For each of the identified river basins, time series of snow cover area will be obtained from satellite observations. Different snow products will be used to test the uncertainty in satellite snow cover. Climate time-series of precipitation, temperature and solar radiation used by the model will be analyzed to evaluate the snowmelt coefficient. First, the coefficient will be recalculated by forcing the model with the snow cover depletion provided by the satellite observations. Secondly, a snow water equivalent (SWE) reconstruction exercise will be performed. Also, the radiation component will be included in the snowmelt module. Finally, a validation activity is foreseen.

The duration of the activities is six months. The work will produce a consistent dataset of time series of snow cover and weather forcing (precipitation, temperature and radiation) for the selected river basin, as well as estimated snowmelt coefficients for temperature alone and for a combination of temperature and radiation. The datasets will be organized in NetCDF. The results will be accompanied by a short technical report containing the relevant metadata, description and interpretation of the results, with possible recommendations also in view of a possible improvement of the snow module of the LISFLOOD model. The work is expected to contribute to a report or scientific paper, to be developed in collaboration between the JRC, on the evaluation of the snow module of the LISFLOOD model.

Activities performed in 2024:

• The Snow Cover Area time-series have been derived for nine hydrological catchments in Europe;
• The time-series have been extensively evaluated against other products;
• The new melting coefficient has been estimated pixel-wise for all the basins by considering the observed SCA and compared with the coefficient calibrated with the hydrological model;
• A scientific publication is in preparation.