Leszek Kuchar (Poland) 1; Slawomir Iwanski (Poland) 1; Leszek Jelonek (Poland) 2
1 - Wroclaw University of Environmental and Life Sciences, Department of Mathematics, Wroclaw (Poland); 2 - Institute of Meteorology and Water Management, Wroclaw (Poland)
A new simulation of maximum and minimum daily flows for the Kaczawa River in south-west Poland and the year 2080 are presented.
The flow simulation in the river catchment was made using MIKE SHE hydrological model and long series of generated data for 24 sites of meteorological stations. Generated data as solar radiation, maximum temperature, minimum temperature and total rainfall were set up using spatial weather generator SWGEN producing the multisite daily time series based on 35 years of observed data gathered from the Institute of Meteorology and Water Management National Research Institute (IMGW). Data were generated for the present (the year 2000 are used as a background) as well for future climate condition for 2080 according Representative Concentration Pathways (RCPs) scenarios. The large number of new simulated series determined by the lead time, three climate change scenarios (RCP4.5, RCP6.0 and RCP8.5), and number of generated years (1000 for each case) is equal to 5000 for a single station. Finally, lognormal pdf function for the maximum and minimum flows are presented as well probability of exceedance of maximum/minimum values.
The simulated maximum and minimum annual flows predicted for 2080 according to the averaged scenarios RCP4.5 and RCP6.0 are consistent with the maximum and minimum annual flows obtained for the SRES A1B scenarios (GISS Model E, HadCM3 and GFDL R15) in earlier studies. A 10–20 percent increase in the maximum and minimum annual daily flows in the case of significant water deficits in Poland is not a hydrological risk to the catchment of the Kaczawa River.
The long series of simulated years and the large number of stations used in calculations based on 35 years of observation allow us to believe that the simulations in flow changes in Kaczawa basin are reliable. The use of the hydrological rainfall-runoff model MIKE SHE together with the spatial weather generator SWGEN enables effective assessment of changes in flows in river basins with a long time horizon.