Reconstruction of flood events based on documentary data and transnational flood risk analysis of the Upper Rhine and its French and German tributaries since AD 1480

Abstract

Abstract. This paper presents the long-term analysis of flood occurrence along the southern part of the Upper Rhine River system and of 14 of its tributaries in France and Germany covering the period starting from 1480 BC. Special focus is given on the temporal and spatial variations of flood events and their underlying meteorological causes over time. Examples are presented of how long-term information about flood events and knowledge about the historical aspect of flood protection in a given area can help to improve the understanding of risk analysis and therefor transnational risk management. Within this context, special focus is given to flood vulnerability while comparing selected historical and modern extreme events, establishing a common evaluation scheme.The transnational aspect becomes especially evident analyzing the tributaries: on this scale, flood protection developed impressively different on the French and German sides. We argue that comparing high technological standards of flood protection, which were initiated by the dukes of Baden on the German side starting in the early 19th century, misled people to the common belief that the mechanical means of flood protection like dams and barrages can guarantee the security from floods and their impacts. This lead to widespread settlements and the establishment of infrastructure as well as modern industries in potentially unsafe areas until today. The legal status in Alsace on the French side of the Rhine did not allow for continuous flood protection measurements, leading to a constant -and probably at last annoying -reminder that the floodplains are a potentially unsafe place to be. From a modern perspective of flood risk management, this leads to a significant lower aggregation of value in the floodplains of the small rivers in Alsace compared to those on the Baden side -an interesting fact -especially if the modern European Flood directive is taken into account.

Defining and Analyzing the Frequency and Severity of Flood Events to Improve Risk Management from a Reinsurance Standpoint

“…One goal of this type of analysis is to determine if floods are 65 occurring more often and with increased severity due to climate change or other anthropogenic 66 causes (Himmelsbach et al 2015). Public databases are comprised of documentary sources and 67 trained spotter observations (NCDC, EM-Dat, and DFO).…”

“…However in an area like Los Angeles that similar minor 77 flooding may be reported, which affects the frequencies of flooding in each area. Another source 78 of flood occurrence information is using a documentary source, which involves examining media 79 sources as well as government reports to comprise a set of occurrences across a state, country or 80 globe (Himmelsbach et al 2015 andDoocy et al 2013). These sources rely heavily on the 81 quality of the reporting, using the reports to assign severity and frequency estimates to cover an 82 expansive region.…”

Defining and analyzing the frequency and severity of flood events to improve risk management from a reinsurance standpoint

“…However in an area like Los Angeles that similar minor flooding may be reported, which affects the frequencies of flooding in each area. Another source of flood occurrence information is using a documentary source, which involves examining media sources as well as government reports to comprise a set of occurrences across a state, a country or the globe (Himmelsbach et al, 2015;Doocy et al, 2013). These sources rely heavily on the quality of the reporting, using the reports to assign severity and frequency estimates to cover an expansive region.…”

“…One goal of this type of analysis is to determine if floods are occurring more often and with increased severity due to climate change or other anthropogenic causes (Himmelsbach et al, 2015). Public databases are comprised of documentary sources and trained spotter observations (NCDC, EM-Dat, and DFO).…”

“…The NCDC Storm Data database is a compiled set of observations from National Oceanic and Atmospheric Administration (NOAA) trained spotters. NCDC events are categorized by county and then separated by dates (Dobour and Noel, 2005;Gaffin and Hotz, 2000). EM-DAT catalogues events by year with summary statistics detailing frequency and overall event impacts (i.e., deaths and losses) from that year.…”