Simulation of the minimum annual river flows based on the RCP climatic scenario, time horizon up to 2060-2080 and the Kaczawa River

Abstract

In this paper a new simulations of minimum daily flow for Kaczawa River a left side tributary of the Odra River in south-west Poland are presented. Generated data were made based on very long series of 35 years of observed data and 24 sites of meteorological stations for south-west Poland gathered from the the Institute of Meteorology and Water Management National Research Institute (IMGW). For the data generation the spatial weather generator SWGEN producing the multisite daily time series was applied. Data were generated for the present (the year 2000 are used as a background) as well for future climate condition for 2060 and 2080 according Representative Concentration Pathways (RCPs) scenarios. The flow simulation in the river catchment is made using MIKE SHE hydrological model. Simulations are done for 2060 and 2080. The large number of new simulated series determined by the lead time, two climate change scenarios (RCP4.5 and RCP6.0), and number of generated years (1000 for each case) is equal to 5000 for a single station. Finally, Lognormal Pdf function for the minimum flow is presented as well probability of exceedance of minimum values.

Comparison of daily flows simulated for the year 2060 on the Kaczawa River for various scenarios of climate change by simple time series analysis

“…This work is a continuation of earlier studies on changes in the Kaczawa River flows simulated for various scenarios of climate change [14][15][16][17]. The following studies compared the time series of daily flows in a period of the year in contrast to previous studies on the probability distributions of flows, e.g.…”

“…As in previous studies, the simulation of river flows for the future climate is carried out in three stages [14][15][16][17]. Climate description of all meteorological stations are prepared using an observed data.…”

“…This is step 3. The described procedure is presented in Figure 1 originally described in the papers [16,17] and has been used many times to simulate processes in river catchment [14][15][16][17]. The daily flows sequences obtained are the basis for analysis illustrating the hydrological effect of climate changes in rivers [5,16,17,22,24].…”

“…For example, floods in Poland, which are accompanied by high flows, appeared mainly in the summer. However, in the last 20 years, as a results of changes in the course of winters, mainly higher temperatures, meltwater thaw floods began to appear more frequently and on a much larger scale [15,19,23]. In the studies, flows were simulated for the year 2060 according to the three most likely scenarios GISS Model E, HadCM3, and GFDL R15 which are considered to comply with the new scenarios of Representative Concentration Routes (RCPs) 4.5 and 6.0.…”

“…In the studies, flows were simulated for the year 2060 according to the three most likely scenarios GISS Model E, HadCM3, and GFDL R15 which are considered to comply with the new scenarios of Representative Concentration Routes (RCPs) 4.5 and 6.0. Three selected SRES scenarios were adopted in the present study due to the extensive experience in generating meteorological data for these scenarios for the condition of Poland, as well as due to their high convergence with the RCP4.5 and RCP6.0 scenarios [7,8,15]. It has been assumed that the background in the research, i.e.…”