Iwona Pińskwar

Trend detection in river flow series: 1. Annual maximum flow / Détection de tendance dans des séries de débit fluvial: 1. Débit maximum annuel

Abstract Results of a study on change detection in hydrological time series of annual maximum river flow are presented. Out of more than a thousand long time series made available by the Global Runoff Data Centre (GRDC) in Koblenz, Germany, a worldwide data set consisting of 195 long series of daily mean flow records was selected, based on such criteria as length of series, currency, lack of gaps and missing values, adequate geographical distribution, and priority to smaller catchments. The analysis of annual maximum flows does not support the hypothesis of ubiquitous growth of high flows. Although 27 cases of strong, statistically significant increase were identified by the Mann-Kendall test, there are 31 decreases as well, and most (137) time series do not show any significant changes (at the 10% level). Caution is advised in interpreting these results as flooding is a complex phenomenon, caused by a number of factors that can be associated with local, regional, and hemispheric climatic processes. Moreover, river flow has strong natural variability and exhibits long-term persistence which can confound the results of trend and significance tests.

Large floods in Europe, 1985–2009

Abstract The paper looks at two metrics of flood events: flood severity (related to flood frequency) and flood magnitude (related to flood severity, as above, but also to flood duration and affected area). A time series of flood information, over 25 years, collected by the Dartmouth Flood Observatory, is used to describe the spatio-temporal variability of large floods in Europe. Direct factors responsible for changes in flood severity and magnitude over time may be related to both climate and ground surface changes. Indirect links between flood severity/magnitude and socio-economic indices occur via flood risk reduction activities, land-use change and land-cover change. The present analysis shows an increasing trend during the 25-year period in the number of reported floods exceeding severity and magnitude thresholds. Editor D. Koutsoyiannis Citation Kundzewicz, Z.W., Pińskwar, I., and Brakenridge, G.R., 2013. Large floods in Europe, 1985–2009. Hydrological Sciences Journal, 58 (1), 1–7.

Variability of high rainfalls and related synoptic situations causing heavy floods at the northern foothills of the Tatra Mountains

This contribution provides the basics of the climatology of the Polish Tatra Mountains in a nutshell, with particular reference to intense precipitation and its relation to atmospheric circulation. Variability of various precipitation characteristics, including selected indices of intense precipitation in Zakopane and at Kasprowy Wierch, is illustrated in this paper. None of the trends in these characteristics and indices calculated for the entire time interval exhibit a statistical significance, but short-time fluctuations are evident. The occurrence of intense precipitation in the Tatra Mountains is strongly related to three circulation types. These situations (Nc, NEc, Bc) are associated with cyclones following track Vb after van Bebber. In addition to changing frequencies of circulation, this study also reveals an increase in the frequency of the circulation types associated with extreme precipitation.

Floods at the northern foothills of the Tatra Mountains — A Polish-Swiss research project

The present paper introduces the topical area of the Polish-Swiss research project FLORIST (Flood risk on the northern foothills of the Tatra Mountains), informs on its objectives, and reports on initial results. The Tatra Mountains are the area of the highest precipitation in Poland and largely contribute to flood generation. The project is focused around four competence clusters: observation-based climatology, model-based climate change projections and impact assessment, dendrogeomorphology, and impact of large wood debris on fluvial processes. The knowledge generated in the FLORIST project is likely to have impact on understanding and interpretation of flood risk on the northern foothills of the Tatra Mountains, in the past, present, and future. It can help solving important practical problems related to flood risk reduction strategies and flood preparedness.

Changes of snow cover in Poland

The present paper examines variability of characteristics of snow cover (snow cover depth, number of days with snow cover and dates of beginning and end of snow cover) in Poland. The study makes use of a set of 43 long time series of observation records from the stations in Poland, from 1952 to 2013. To describe temporal changes in snow cover characteristics, the intervals of 1952–1990 and of 1991–2013 are compared and trends in analysed data are sought (e.g., using the Mann–Kendall test). Observed behaviour of time series of snow-related variables is complex and not easy to interpret, for instance because of the location of the research area in the zone of transitional moderate climate, where strong variability of climate events is one of the main attributes. A statistical link between the North Atlantic Oscillation (NAO) index and the snow cover depth, as well as the number of snow cover days is found.

Observed Changes in Air Temperature and Precipitation and Relationship between them, in the Upper Vistula Basin

The chapter presents changes in air temperature and precipitation in the Upper Vistula Basin. Data from 18 meteorological stations covering the 1951–2015 period was used to investigate variability and trends in air temperature, precipitation and linkages between them. Air temperature in the Upper Vistula Basin was significantly rising during the research period. Distinct warming on annual scale started in the first half of the eighties. Spring and summer air temperatures have been significantly increasing; winter air temperature trends were much weaker while no significant changes were found in autumn. Upward trends in air temperature within the Upper Vistula Basin were also reflected in the frequency of thermally characteristic days which was significantly changing during the research period. Strong downward trends were found in the frequency of winter days (Tavg ≤ 0 °C) while trends in warm characteristic days were positive. Most observed changes in precipitation were not statistically significant at the level of 0.05. This indicates that significant increase in air temperature is not currently accompanied by significant increase in precipitation thus changes in precipitation are not directly related to changes in air temperature and they possibly vary in time. Relations between precipitation and air temperature are not straightforward. The results indicate that strong increase in air temperature is rather accompanied by decrease in precipitation frequency and amount. However, this applies only to overall precipitation totals and not to extreme events which are random and can occur unexpectedly. Flood precipitation can also occur during drier periods, as in the last decade of the research period. It however must be mentioned that for nearly all stations mean precipitation totals from the warmer period of 1991–2013 (1991–2011) were higher than in previous period 1961–1990. Moreover the study revealed that increasing, statistically significant, trend (from 0.15 to 0.24 °C/decade) in mean annual air temperature likely impacted changes in heavy precipitation. The links between air temperature ranges (0–10, 10–20 °C and above 20 °C) and precipitation ranges (0–10 mm, 10–20 mm, etc. to above 50 mm) for two periods examined at nine stations in the Upper Vistula Basin revealed that when air temperature exceeded 20 °C more intense precipitation was observed in the second warmer period 1991–2013.

Changes of flood risk on the northern foothills of the Tatra Mountains

The present paper reviews selected outcomes of the FLORIST project devoted to flood risk in the region of the northern foothills of the Tatra Mountains in Poland and summarizes novel results. The project encompassed theoretical, field, and modeling work. It was focused around observation-based hydroclimatology; projections for the future; dendrogeomorphology; as well as influence of transport of large wood on fluvial processes. The project improved understanding and interpreting changes in high-flow frequency and magnitude as well as changes in flood risk in the region, related to the presence of large wood in mountain streams. A unique database on past episodes of intense precipitation and flooding was created, harnessing multiple sources. The project showed that the analysis of tree rings and wood logs can offer useful information, complementing and considerably enriching the knowledge of river floods in the region of northern foothills of the Tatra Mountains. Retrospective and scenario-defined modeling of selected past fluvial events in the region was also performed.

Projections of Precipitation in the Northern Foothills of the Tatra Mountains

Floods are usually related to extreme and/or long-lasting intense precipitation events. In warmer climate, future precipitation extremes could be higher than nowadays. Assessment of these future changes and climate adaptation to future flood risk are very important issues. In this study, four regional climate models and seven global climate models for two climate scenarios A1B and A2 were used to get better description of the range of changes in annual as well as extreme precipitation events. With help of the delta-change method, projections were made based on responses from regional and global climate models, for 11 precipitation stations in the Tatra Mountains in Poland, for which observation data for 1961–1990 were available. Analyses were made of various indices, such as annual totals, maximum 24 h, 5-day; 10-day, monthly maximum sum of precipitation and also numbers of days with intense precipitation equal or above the thresholds of 30 and 50 mm. It was found that all RCM and GCM models under examination project an increase in mean annual precipitation totals as well as in heavy precipitation in two future time windows considered (2061–2090 and 2080–2100).

Correction to: Observed changes in extreme precipitation in Poland: 1991–2015 versus 1961–1990

The original version of this article unfortunately contained a mistake. Fig. 3b was incorrect. The correct version of Fig. 3b is given below.

Civil Security Governance Systems in the New EU Member States: Closer to 'Old Europe' or a Distinctive Path?

Natural and man-made risks cause substantial and growing losses in Europe and the world (Howell, 2013; Smith, 2013), which poses challenges for national civil security governance systems (CSGSs), understood here as the organizations and processes engaged in the prevention of, preparedness for, mitigation of, response to and recovery from crises and disasters (see Bossong and Hegemann, in the introduction to this volume). Yet, even across European countries such systems have only fully emerged over the last three decades in a rather uneven manner (Quarantelli, 2000). In Western European countries, an important shift occurred in the last quarter of the 20th century when more attention was paid to the protection of civilians during peacetime, which we call civil security, rather than to military defence. In the New Member States of the EU and especially in Central European states, however, civil security started to gain importance in national policy-making and post-Communist transition only since the very late 1990s (Brazova et al., 2014).