Global climate change is anticipated to have consequences on water resources and the envi-ronment both at global and local/regional levels. Efforts towards proper management of future water resources and resolving potential water-related conflicts require the formulation of appropriate techniques to downscale the output of global climate models (GCM) to local conditions for hydrologic prediction. The paper presents an integrated framework for modeling the impact of climate change on river runoff that combines methodology for downscaling climate change scenarios for a basin scale with a hydrological model to estimate the impact of climate change on a river runoff. The modeling framework uses long-term observations of meteorological and hydrological variables together with a climate change scenario to provide a projection of future flows for the specified time horizon. The framework is based on a spatial weather generator and a distributed rainfall-runoff model. Such a configuration enables a reflection of the uncertainty of future conditions by running multiple realizations of future conditions, and also take into account the spatial variability of hydrological properties in the catchment by maintaining the physical details at a given grid size.The performance of the framework was presented for the Kaczawa basin that is one of the main left bank tributaries of the Odra River -the second biggest river in Poland. The results show simulated changes of the future river flow regime caused by climatic changes for two time horizons: 2040 and 2080.

In this study, the impacts of climate change on streamflow are investigated. The ensemble of outputs from three different Global Circulation Models models: GISS, CCCM, GFDL developed for the emission scenario A1B were analyzed to infer projected changes in climatological conditions for the region of the Upper and Middle Odra basin. Obtaining hydrological scenarios of future changes for the scale of subcatchment required simulating short-term and fine scaled weather patterns for this area. SWGEN model (Spatial Weather GENerator) was applied to downscale projected changes of climatological conditions to the ones required by hydrological model temporal and spatial resolution. Daily time series of solar radiation, temperature and precipitation were generated for the reference period 1981–2000 and for the time horizon 2030 and 2050. The generated data from SWGEN model were integrated in the hydrological model NAM to simulate streamflow under changed conditions with daily time step. The results show considerable changes in annual and seasonal runoff daily distributions for selected study catchment in the future time horizons of 2030 and 2050.

Abstract.A new simulation of daily flow for Kaczawa River, south-west Poland for extra long series of generated meteorological data (comparing to previous research) and selected climate change scenarios are presented. The Representative Concentration Pathways (RCPs) scenarios vs. SRES are introduced for simulations. The flow simulation in the river catchment is made using MIKE SHE hydrological model while the multisite data are generated by spatial weather generator SWGEN. Simulations are done for 2040 and 2060 while the simulations for the year 2000 are used as a background. The large number of new simulated series determined by the lead time, three climate change scenarios (RCP2.6 RCP4.5 and RCP6.0), and number of generated years (1000 for each case) is equal to 7000 for a single station. Finally, Pdf function for flow is presented as well probability of exceedance of maximum flow.

This article attempts to assess the future occurrence of a drought using the Sieljaninova hydrothermal index (HTC). Air temperature and total precipitation were simulated for current conditions (2000) and forecast for eight locations of meteorological stations in Poland according to the HAD and GFDL scenarios for RCP 45 and 60 for 2040 and 2060.

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.