ALBERT

Description: Rivers have always flooded their floodplains. Over 2.5 billion people worldwide have been affected by flooding in recent decades. The economic damage is also considerable, averaging 100 billion US dollars per year. There is no doubt that damage and other negative effects of floods can be avoided. However, this has a price: financially and politically. Costs and benefits can be estimated through risk assessments. Questions about the location and frequency of floods, about the objects that could be affected and their vulnerability are of importance for flood risk managers, insurance companies and politicians. Thus, both variables and factors from the fields of hydrology and sociol-economics play a role with multi-layered connections. One example are dikes along a river, which on the one hand contain floods, but on the other hand, by narrowing the natural floodplains, accelerate the flood discharge and increase the danger of flooding for the residents downstream. Such larger connections must be included in the assessment of flood risk.

Description: Flüsse haben seit jeher ihre Auen überflutet. In den vergangenen Jahrzehnten waren weltweit über 2,5 Milliarden Menschen durch Hochwasser betroffen. Auch der ökonomische Schaden ist mit durchschnittlich 100 Milliarden US Dollar pro Jahr erheblich. Zweifelsohne können Schäden und andere negative Auswirkungen von Hochwasser vermieden werden. Allerdings hat dies einen Preis: finanziell und politisch. Kosten und Nutzen lassen sich durch Risikobewertungen abschätzen. Dabei werden in der Wasserwirtschaft, von Versicherungen und der Politik Fragen nach dem Ort und der Häufigkeit von Überflutungen, nach den Dingen, die betroffen sein könnten und deren Anfälligkeit untersucht. Somit spielen sowohl Größen und Faktoren aus den Bereichen der Hydrologie und Sozioökonmie mit vielschichtigen Zusammenhängen eine Rolle. Ein anschauliches Beispiel sind Deiche entlang eines Flusses, die einerseits in ihrem Abschnitt Überflutungen eindämmen, andererseits aber durch die Einengung der natürlichen Vorländer den Hochwasserabfluss beschleunigen und die Gefährdung für die Anlieger flussab verschärfen. Solche größeren Zusammenhänge müssen in der Bewertung des Hochwasserrisikos einbezogen werden. In derzeit gängigen Verfahren geht dies mit vereinfachenden Annahmen einher. Risikoabschätzungen sind daher unscharf und mit Unsicherheiten verbunden. Diese Arbeit untersucht den Nutzen und die Möglichkeiten neuer Datensätze für eine Verbesserung der Hochwasserrisikoabschätzung. Es werden neue Methoden und Modelle entwickelt, die die angesprochenen Zusammenhänge stärker berücksichtigen und auch die bestehenden Unsicherheiten der Modellergebnisse beziffern und somit die Verlässlichkeit der getroffenen Aussagen einordnen lassen. Dafür werden Daten zu Hochwasserereignissen aus verschiedenen Quellen erfasst und ausgewertet. Dazu zählen neben Niederschlags-und Durchflussaufzeichnungen an Messstationen beispielsweise auch Bilder aus sozialen Medien, die mit Ortsangaben und Bildinhalten helfen können, die Überflutungsflächen abzugrenzen und Hochwasserschäden zu schätzen. Verfahren des Maschinellen Lernens wurden erfolgreich eingesetzt, um aus vielfältigen Daten, Zusammenhänge zwischen Hochwasser und Auswirkungen zu erkennen, besser zu verstehen und verbesserte Modelle zu entwickeln. Solche Risikomodelle helfen bei der Entwicklung und Bewertung von Strategien zur Minderung des Hochwasserrisikos. Diese Werkzeuge ermöglichen darüber hinaus Einblicke in das Zusammenspiel verschiedener Faktoren sowie Aussagen zu den zu erwartenden Folgen auch von Hochwassern, die das bisher bekannte Ausmaß übersteigen. Diese Arbeit verzeichnet Fortschritte in Bezug auf eine verbesserte Bewertung von Hochwasserrisiken durch die Nutzung vielfältiger Daten aus unterschiedlichen Quellen mit innovativen Verfahren sowie der Weiterentwicklung von Modellen. Das Hochwasserrisiko unterliegt durch wirtschaftliche Entwicklungen und klimatische Veränderungen einem steten Wandel. Um das Wissen über Risiken aktuell zu halten sind robuste, leistungs- und anpassungsfähige Verfahren wie sie in dieser Arbeit vorgestellt werden von zunehmender Bedeutung.

Description: This data set provides a set of residential flood loss maps (ESRI Shapefiles) for the German part of the Danube catchment for current and future climate based on a stochastic event set of flood hazard footprints (Schröter et al. 2017; http://doi.org/10.5880/GFZ.5.4.2017.003). The multi-polygon maps provide flood loss in EUR for residential land use areas according to the ATKIS (Authoritative Topographic Cartographic Information System) codes residential areas (2111) and areas of mixed use (2113), (BKG GEODATENZENTRUM: ATKIS-Basis-DLM, 2005). Loss values are calculated using the FloodLossEstimationMOdel for the residential sector (FLEMOps+r) developed by Elmer et al. (2010) in combination with exposure data based on total replacement costs for residential buildings (Kleist et al., 2006). Asset values with a spatial resolution corresponding to the underlying inundation depth maps of the stochastic event set (100x100 m) have been derived by applying a binary disaggregation method and using the digital basic landscape model ATKIS as ancillary information (Wünsch et al. 2009). The flood event sets are derived for the historical period (1970-1990) and two RCPs (4.5 and 8.5) for the near future (2020-2049) and far future (2070-2099) for four CORDEX models. These flood event sets are created within continuous long-term simulations of a coupled model chain including the IMAGE stochastic multi-variable, multi-site weather generator, the eco-hydrological model SWIM and 1D river network coupled with 2D hydro-numeric hinterland inundation model, see Schröter et al. (2017) for further details The data have been produced within the OASIS+ demonstrator project 'Future Danube Multi Hazard and Risk Model' funded by Climate-KIC in the period from January 2016 to December 2017. Key features: • Flood loss maps for residential areas in the German part of the Danube catchment from stochastic flood event sets for current and future climate. • High spatial resolution for ATKIS residential land use areas intersected with 100x100 m inundation depth maps. • Flood loss scenarios for historical period (1970-1990) and two RCPs (4.5 and 8.5) for the near future (2020-2049) and far future (2070-2099) from four CORDEX models Key usage: • Large-scale flood risk assessment • Future flood risk assessment • Flood risk management with long-term perspective A full description of the data provenance and specification is given in the README_Schroeter-et-al-2017-004.txt file available in the data download section at this DOI Landing Page.

Description: Increasing flood losses over the last decades emphasize the need towards significantly improved and more efficient flood risk management. One key requirement is reliable risk assessment in conjunction with consistent flood loss modeling. Current risk assessments and flood loss estimations for Europe are until now based on regional approaches using deterministic depth-damage function and do rarely report associated uncertainties. To reduce these shortcomings, we present the results of a novel, consistent approach based on the Bayesian Network Flood Loss Estimation MOdel for the private sector (BN-FLEMOps). The dataset is consistent in terms of the input data used to drive the model and because we use the same vulnerability model to derive the flood loss estimation. Essential inputs for any flood loss estimation are hazard (usually water depth), asset (value of objects at risk) and flood experience parameters. The hazard input was given by a European inundation scenario for a continent-wide flood with 100 years return period (Alfieri et al., 2014). Asset values were computed following the the approach by Huizinga et al. (2017) and the flood experience was derived using the database of the Dartmouth Flood Observatory (DFO) (Brakenridge, 2018).

Description: The dataset comprises a range of variables describing characteristics of flood events and river catchments for 480 gauging stations in Germany and Austria. The event characteristics are asscoiated with annual maximum flood events in the period from 1951 to 2010. They include variables on event precipitation, antecedent catchment state, event catchment response, event timing, and event types. The catchment characteristics include variables on catchment area, catchment wetness, tail heaviness of rainfall, nonlinearity of catchment response, and synchronicity of precipitation and catchment state. The variables were compiled as potential predictors of heavy tail behaviour of flood peak distributions. They are based on gauge observations of discharge, E-OBS meteorological data (Haylock et al. 2008), mHM hydrological model simulations (Samaniego et al., 2010), 4DAS climate reanalysis data (Primo et al., 2019), and the 25x25 m resolution EU-DEM v1.1. A short description of the data processing is included in the file inventory and more details can be found in Macdonald et al. (2022).

Description: floodsimilarity provides classes and methods to conduct a similarity analysis between multiple flood events. The library mainly consists of two parts: (1) algorithms to compute indices and other statistics based on pandas and xarray (2) well-defined data structures for data exchange (e.g. through the Similarity Backend Module) floodsimilarity is used by the Digital Earth Similarity Backend Module (Eggert, 2021) as part of the Digital Earth Flood Event Explorer. It is developed at the GFZ German Research Centre for Geosciences and funded by the Initiative and Networking Fund of the Helmholtz Association through the Digital Earth project.

Description: The Digital Earth Flood Event Explorer supports geoscientists and experts to analyse flood events along the process cascade event generation, evolution and impact across atmospheric, terrestrial, and marine disciplines. It applies the concept of scientific workflows and the component-based Data Analytics Software Framework (DASF, Eggert and Dransch, 2021) to an exemplary showcase. It aims at answering the following geoscientific questions: - How does precipitation change over the course of the 21st century under different climate scenarios over a certain region? - What are the main hydro-meteorological controls of a specific flood event? - What are useful indicators to assess socio-economic flood impacts? - How do flood events impact the marine environment? - What are the best monitoring sites for upcoming flood events? The Flood Event Explorer developed scientific workflows for each geoscientific question providing enhanced analysis methods from statistics, machine learning, and visual data exploration that are implemented in different languages and software environments, and that access data form a variety of distributed databases. The collaborating scientists are from different Helmholtz research centers and belong to different scientific fields such as hydrology, climate-, marine-, and environmental science, and computer- and data science. It is funded by the Initiative and Networking Fund of the Helmholtz Association through the Digital Earth project (https://www.digitalearth-hgf.de/).

Description: As the negative impacts of hydrological extremes increase in large parts of the world, a better understanding of the drivers of change in risk and impacts is essential for effective flood and drought risk management and climate adaptation. However, there is a lack of comprehensive, empirical data about the processes, interactions and feedbacks in complex human-water systems leading to flood and drought impacts. To fill this gap, we present an IAHS Panta Rhei benchmark dataset containing socio-hydrological data of paired events, i.e. two floods or two droughts that occurred in the same area (Kreibich et al. 2017, 2019). The contained 45 paired events occurred in 42 different study areas (in three study areas we have data on two paired events), which cover different socioeconomic and hydroclimatic contexts across all continents. The dataset is unique in covering floods and droughts, in the number of cases assessed and in the amount of qualitative and quantitative socio-hydrological data contained. References to the data sources are provided in 2022-002_Kreibich-et-al_Key_data_table.xlsx where possible. Based on templates, we collected detailed, review-style reports describing the event characteristics and processes in the case study areas, as well as various semi-quantitative data, categorised into management, hazard, exposure, vulnerability and impacts. Sources of the data were classified as follows: scientific study (peer-reviewed paper and PhD thesis), report (by governments, administrations, NGOs, research organisations, projects), own analysis by authors, based on a database (e.g. official statistics, monitoring data such as weather, discharge data, etc.), newspaper article, and expert judgement. The campaign to collect the information and data on paired events started at the EGU General Assembly in April 2019 in Vienna and was continued with talks promoting the paired event data collection at various conferences. Communication with the Panta Rhei community and other flood and drought experts identified through snowballing techniques was important. Thus, data on paired events were provided by professionals with excellent local knowledge of the events and risk management practices.