Flood triggering in Switzerland: the role of daily to monthly preceding precipitation

Determining the role of different precipitation periods for peak discharge generation is crucial for both projecting future changes in flood probability and for short- and medium-range flood forecasting. In this study, catchment-averaged daily precipitation time series are analyzed prior to annual peak discharge events (floods) in Switzerland. The high number of floods considered – more than 4000 events from 101 catchments have been analyzed – allows to derive significant information about the role of antecedent precipitation for peak discharge generation. Based on the analysis of precipitation times series, a new separation of flood-related precipitation periods is proposed: (i) the period 0 to 1 day before flood days, when the maximum flood-triggering precipitation rates are generally observed, (ii) the period 2 to 3 days before flood days, when longer-lasting synoptic situations generate "significantly higher than normal" precipitation amounts, and (iii) the period from 4 days to 1 month before flood days when previous wet episodes may have already preconditioned the catchment. The novelty of this study lies in the separation of antecedent precipitation into the precursor antecedent precipitation (4 days before floods or earlier, called PRE-AP) and the short range precipitation (0 to 3 days before floods, a period when precipitation is often driven by one persistent weather situation like e.g., a stationary low-pressure system). A precise separation of "antecedent" and "peak-triggering" precipitation is not attempted. Instead, the strict definition of antecedent precipitation periods permits a direct comparison of all catchments. The precipitation accumulating 0 to 3 days before an event is the most relevant for floods in Switzerland. PRE-AP precipitation has only a weak and region-specific influence on flood probability. Floods were significantly more frequent after wet PRE-AP periods only in the Jura Mountains, in the western and eastern Swiss plateau, and at the outlet of large lakes. As a general rule, wet PRE-AP periods enhance the flood probability in catchments with gentle topography, high infiltration rates, and large storage capacity (karstic cavities, deep soils, large reservoirs). In contrast, floods were significantly less frequent after wet PRE-AP periods in glacial catchments because of reduced melt. For the majority of catchments however, no significant correlation between precipitation amounts and flood occurrences is found when the last 3 days before floods are omitted in the precipitation amounts. Moreover, the PRE-AP was not higher for extreme floods than for annual floods with a high frequency and was very close to climatology for all floods. The fact that floods are not significantly more frequent nor more intense after wet PRE-AP is a clear indicator of a short discharge memory of Pre-Alpine, Alpine and South Alpine Swiss catchments. Our study poses the question whether the impact of long-term precursory precipitation for floods in such catchments is not overestimated in the general perception. The results suggest that the consideration of a 3–4 days precipitation period should be sufficient to represent (understand, reconstruct, model, project) Swiss Alpine floods.

The Sicilian coinage of Henry VI - mint attributions reconsidered

The Sicilian Coinage of the Hohenstaufen has been studied since the 17th century. Today, with the splendid Medieval European Coinage 14 at our hands, scholars are still struggling when it comes to mint attributions for Henry’s Sicilian denari and taris: Palermo or Messina? Palermo and Messina? The coin finds from Monte Iato (PA) may shed light on this old problem: by starting from one coin type alone and examining the different subtypes and variants, we can catch a glimpse of the way coinage was organised in Sicily at the end of the 12th century.

Henry Haynie [Illustration] : (Redakteur des "Chicago Herold")

Friedrich Beer

Hermann Todesko [Illustration] : geb. 1791 - gest. 1844

Scan von Monochrom-Mikroform

Henry Seligman [Illustration] : (Porträt)

Scan von Monochrom-Mikroform

Antwort des Reverend William Henry Hechler

William Hechler

Shakespeare's Richard II and Henry V and Political Rebellions in the Reign of Queen Elizabeth I

The purpose of this thesis will be to examine how two acts of rebellion against Queen Elizabeth I influenced Shakespeare's writing of Richard II and Henry V, as well as the performance and publication of these plays. The treasonous plots and execution of Mary, Queen of Scots in the 1580s, as well as the failed Essex Rebellion of 1601, resulted in a sensitivity towards any writings that seemed to support a coup d'état. Shakespeare, being a well-informed and fairly well-connected playwright, wrote passages in the afore mentioned plays that clearly reflect the political turmoil of the times. Thus, his plays were censored both on stage and in print until after the death of Elizabeth in 1603.

Die Schuldennot der jüdischen Gemeinde Metz : (1791 - 1854)

Nathan Netter

Die Schuldennot der jüdischen Gemeinde Metz : (1791 - 1854)

Nathan Netter