Validation of precipitation reanalysis products for rainfall-runoff modelling in Slovenia

Alexopoulos, Marcos Julien (author), Müller-Thomy, Hannes (author), Nistahl, Patrick (author), Šraj, Mojca (author), Bezak, Nejc (author)

Observational data scarcity often limits the potential of rainfall-runoff modelling around the globe. In ungauged catchments, earth observations or reanalysis products could be used to replace missing ground-based station data. However, performance of different datasets needs to be thoroughly tested, especially at finer temporal resolutions such as hourly time steps. This study evaluates the performance of ERA5-Land and COSMO-REA6 precipitation reanalysis products (PRPs) using 16 meso-scale catchments (41–460 km$^2$) located in Slovenia, Europe. These two PRPs are firstly compared with a gridded precipitation dataset that was constructed based on ground observational data. Secondly, a comparison of the temperature data of these reanalysis products with station-based air temperature data is conducted. Thirdly, several data combinations are defined and used as input for the rainfall-runoff modelling using the GR4H model. A special focus is on the application of an additional snow module. Both tested PRPs underestimate, for at least 20 %, extreme rainfall events that are the driving force of natural hazards such as floods. In terms of air temperature, both tested reanalysis products show similar deviations from the observational dataset. Additionally, air temperature deviations are smaller in winter compared to summer. In terms of rainfall-runoff modelling, the ERA5-Land yields slightly better performance than COSMO-REA6. If a recalibration with PRP has been carried out, the performance is similar compared to the simulations where station-based data were used as input. Model recalibration proves to be essential in providing relatively sufficient rainfall-runoff modelling results. Hence, tested PRPs could be used as an alternative to the station-based data in case precipitation or air temperature data are lacking, but model calibration using discharge data would be needed to improve the performance.

• Language: English
• Keywords: hydrology, precipitation, surface runoff, modelling, reanalysis
• Work type: Article
• Typology: 1.01 - Original Scientific Article
• Organization: FGG - Faculty of Civil and Geodetic Engineering
• Publication status: Published
• Publication version: Version of Record
• Year: 2023
• Number of pages: Str. 2559-2578
• Numbering: Vol. 27, iss. 13
• PID: 20.500.12556/RUL-148005
• UDC: 004.4:556.12(497.4)
• ISSN on article: 1607-7938
• DOI: 10.5194/hess-27-2559-2023
• COBISS.SI-ID: 159084291
• Publication date in RUL: 18.07.2023

Record is a part of a journal

• Title: Hydrology and earth system sciences
• Shortened title: Hydrol. earth syst. sci.
• Publisher: Copernicus Publications, European Geosciences Union
• ISSN: 1607-7938
• COBISS.SI-ID: 2823521

Licences

• License: CC BY 4.0, Creative Commons Attribution 4.0 International
• Link: http://creativecommons.org/licenses/by/4.0/
• Description: This is the standard Creative Commons license that gives others maximum freedom to do what they want with the work as long as they credit the author.

Secondary language

• Language: Slovenian
• Keywords: hidrologija, padavine, površinski odtok, modeliranje, reanalize