Trend assessment: Applications for hydrology and climate research

The assessment of trends in climatology and hydrology still is a matter of debate. Capturing typical properties of time series, like trends, is highly relevant for the discussion of potential impacts of global warming or flood occurrences. It provides indicators for the separation of anthropogenic signals and natural forcing factors by distinguishing between deterministic trends and stochastic variability. In this contribution river run-off data from gauges in Southern Germany are analysed regarding their trend behaviour by combining a deterministic trend component and a stochastic model part in a semi-parametric approach. In this way the trade-off between trend and autocorrelation structure can be considered explicitly. A test for a significant trend is introduced via three steps: First, a stochastic fractional ARIMA model, which is able to reproduce short-term as well as long-term correlations, is fitted to the empirical data. In a second step, wavelet analysis is used to separate the variability of small and large time-scales assuming that the trend component is part of the latter. Finally, a comparison of the overall variability to that restricted to small scales results in a test for a trend. The extraction of the large-scale behaviour by wavelet analysis provides a clue concerning the shape of the trend

Trend assessment: applications for hydrology and climate research

The assessment of trends in climatology and hydrology still is a matter of debate. Capturing typical properties of time series, like trends, is highly relevant for the discussion of potential impacts of global warming or flood occurrences. It provides indicators for the separation of anthropogenic signals and natural forcing factors by distinguishing between deterministic trends and stochastic variability. In this contribution river run-off data from gauges in Southern Germany are analysed regarding their trend behaviour by combining a deterministic trend component and a stochastic model part in a semi-parametric approach. In this way the trade-off between trend and autocorrelation structure can be considered explicitly. A test for a significant trend is introduced via three steps: First, a stochastic fractional ARIMA model, which is able to reproduce short-term as well as long-term correlations, is fitted to the empirical data. In a second step, wavelet analysis is used to separate the variability of small and large time-scales assuming that the trend component is part of the latter. Finally, a comparison of the overall variability to that restricted to small scales results in a test for a trend. The extraction of the large-scale behaviour by wavelet analysis provides a clue concerning the shape of the trend

Nonstationary probabilistic downscaling of extreme precipitation

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Spatial assessment of precipitation deficits in the Duero basin (central Spain) with multivariate extreme value statistics

International audienc

From Global to Local and from Local to Global: Examples of Event Scenarios in Europe

The chapter provides two comprehensive scenarios of hazardous events, impacts and damages referring to two opposite scales: the first one explores the local differences of a global hazard whilst the second addresses the potential regional, national and European implications of a local disaster. In detail, the Italian Authors have focused on the Vesuvius’ scenario, which provides a qualitative description of a potential volcanic event which might occur in the Campania Region, Southern Italy, and of its main consequences. The scenario is addressed at highlighting how, during an eruption, different volcanic phenomena characterized by different lengths and affecting heterogeneous territorial targets, may induce numerous types of damages, failures and troubles at different geographical scales, from the local one, whose extension largely depends on the hazard scale, up to a European or even a global scale, as recently demonstrated by the eruptions of the Icelandicl volcano

From Global to Local and from Local to Global: Examples of Event Scenarios in Europe

The chapter provides two comprehensive scenarios of hazardous events, impacts and damages referring to two opposite scales: the first one explores the local differences of a global hazard whilst the second addresses the potential regional, national and European implications of a local disaster. In detail, the Italian Authors have focused on the Vesuvius’ scenario, which provides a qualitative description of a potential volcanic event which might occur in the Campania Region, Southern Italy, and of its main consequences. The scenario is addressed at highlighting how, during an eruption, different volcanic phenomena characterized by different lengths and affecting heterogeneous territorial targets, may induce numerous types of damages, failures and troubles at different geographical scales, from the local one, whose extension largely depends on the hazard scale, up to a European or even a global scale, as recently demonstrated by the eruptions of the Icelandicl volcano

Risk futures in Europe

In this section scenario as a concept and a tool will be discussed, tracing a path from the very general and theoretical to the more applied aspects. The notable chapter “The History of the Future”, appearing in a book by Rescher (1991), will be taken as a starting reference. Rescher discusses the increasing importance of futurology in today’s practical life, including policy and science (see also Oreskes, 2000). This focus on the future has become extremely important because of the rapid quantitative and qualitative changes experienced in modern life. It is also a consequence of the role played by science in society in supporting decision-making processes, particularly in the field of risks and environmental issues in general