A b s t r a c tThis paper investigates the variability of drought conditions in Poland in the years 1956-2015 with the use of the Standardized Precipitation-Evapotranspiration Index (SPEI). The study provides a new insight into the phenomenon of the past expansion of the drought-affected area as well as evidence of drying trends in a spatiotemporal context. 3-month, 6-month, and 12-month SPEI were considered, representing drought conditions relevant to agriculture and hydrology. The analysis demonstrates that the spatial extent of droughts shows a broad variability. The annual mean of the percentage of the area under drought has witnessed an increase for all three SPEI timescales. This also pertains to the mean area affected by drought over the growing season (April-September). A decreasing trend in the SPEI values indicates an increase in the severity of droughts over the 60-year period in question in an area extending from the south-west to the central part of Poland.

This study aims to investigate trends and regime changes in streamflow and basic factors driving these changes. The investigated area is located in central Poland and is influenced by temperate transitional climate. New insight is provided into the phenomenon of past climatedriven changes to streamflow patterns over a 65-year period (1951-2015). The Mann-Kendall test for monotonic trends and the CUSUM test are used to determine the presence or absence of changes in climatic variables, shallow groundwater level, and streamflow. Time series are explored to detect the direction of trends and the period when the significant change occurred. Differences in climatic conditions and streamflow patterns are discussed for two sub-periods, before and after the change. Overall, the results suggest stability in precipitation, with limited evidence for change in the annual amount, but reveal a significant change in streamflow regime in the 1980s, attributed to higher temperature driving evapotranspiration and reducing shallow groundwater recharge. It is concluded that the catchment is prone to increased evapotranspiration and in effect to greatly reduced runoff. Keywords Streamflow regime Á Climatic changes Á Groundwater-dominated catchment Á Central Poland

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This study investigates the response of the streamflow to an extremely hot and dry summer 2015 in the urbanized catchment of the Utrata River in central Poland. The objectives were to: reveal changes in the flow regime, assess anomalies in summer river flows, estimate the natural and wastewater effluent contribution and provide an ecological context for the in-stream conditions. The mean annual flow rate in the period 1996-2015 increased by 0.61 m 3 /s as compared to 1951-1970. The mean annual wastewater inflow rate to the river in 2015 was approximately 0.770 m 3 /s, constituting 39% of the observed flow. Almost the entire period of August this contribution approached 100%. The optimum river water temperature threshold for warm-water fish species was exceeded. Streamflow modifications are attributed to an increase of wastewater discharge, urban impact through an increase in imperviousness, and the variability of climatic driving forces.Human-influenced streamflow during extreme drought U. Somorowska and M. Łaszewski

This study assesses the soil water storage in Poland over the years 2000-2015. Soil water storage (SWS) data were acquired from the GLDAS Noah model simulations. The specific objectives were to provide a quantitative assessment of the SWS in the soil layer of 0-50 cm depth to detect extreme stages of SWS, and to provide an insight into the effects of precipitation deficit or surplus on the stage of SWS. Extremely low SWS was

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