Estimation of the impact of climate change-induced extreme precipitation events on floods

• Published in: Contributions to geophysics & geodesy 2015-09, Vol.45 (3), p.173-192
• Main Authors: Hlavčová, Kamila, Lapin, Milan, Valent, Peter, Szolgay, Ján, Kohnová, Silvia, Rončák, Peter
• Format: Article
• Language: English
• Subjects: 5-day precipitation; Air temperature; Atmospheric precipitations; Case studies; Circulation; Climate change; climate change scenarios; Climatic extremes; Educational institutions; Environmental impact; Extreme 5-day precipitation totals; extreme 5-day precipitation totals, climate change scenarios, rainfall-runoff modelling, extreme floods; extreme floods; Extreme weather; Flood regime; Floods; Humidity; Modelling; Mountain regions; Precipitation; Rain; Rainfall runoff; Rainfall-runoff modeling; rainfall-runoff modelling; Rainfall-runoff relationships; River basins; Rivers; Runoff; Specific humidity
• ISSN: 1338-0540; 1335-2806; 1338-0540
• DOI: 10.1515/congeo-2015-0019

In order to estimate possible changes in the flood regime in the mountainous regions of Slovakia, a simple physically-based concept for climate change-induced changes in extreme 5-day precipitation totals is proposed in the paper. It utilizes regionally downscaled scenarios of the long-term monthly means of the air temperature, specific air humidity and precipitation projected for Central Slovakia by two regional (RCM) and two global circulation models (GCM). A simplified physically-based model for the calculation of short-term precipitation totals over the course of changing air temperatures, which is used to drive a conceptual rainfall-runoff model, was proposed. In the paper a case study of this approach in the upper Hron river basin in Central Slovakia is presented. From the 1981–2010 period, 20 events of the basin’s most extreme average of 5-day precipitation totals were selected. Only events with continual precipitation during 5 days were considered. These 5-day precipitation totals were modified according to the RCM and GCM-based scenarios for the future time horizons of 2025, 2050 and 2075. For modelling runoff under changed 5-day precipitation totals, a conceptual rainfall-runoff model developed at the Slovak University of Technology was used. Changes in extreme mean daily discharges due to climate change were compared with the original flood events and discussed.