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Flood Impact (flood + impact)

Distribution by Scientific Domains

Engineering	50%

Selected Abstracts

Uncertainty propagation in a London flood simulation

JOURNAL OF FLOOD RISK MANAGEMENT, Issue 1 2009
B.W. Golding
Abstract Following recent costly flood events in the United Kingdom, there is considerable societal and political pressure to reduce flooding and improve warnings. In response to this, the Flood Risk Management Research Consortium (FRMRC) has been created to investigate the potential of several areas of existing research to be brought into operational use. In this paper, the estimation of flood impact and probability is analysed and illustrated with examples from a simulated forecast of a Thames Estuary flood event carried out at a FRMRC workshop. The forecast modelling chain consisted of meteorology, storm surge, estuary hydrodynamics, defence failure and inundation. The workshop concluded that end-to-end propagation of probability was feasible in an integrated real-time flood forecasting system, and that the basis of such a system had been demonstrated. [source]

Quantifizierung der Schäden infolge Hochwassereinwirkung: Fallstudie Eilenburg

BAUTECHNIK, Issue 12 2005
Jochen Schwarz Dr.-Ing.
Die für das Katastrophenmanagement notwendige Abschätzung der Schäden unter Hochwassereinwirkung ist eine entscheidende, aber bislang methodisch-wissenschaftlich noch unzureichend vorbereitete Aufgabenstellung. In Anlehnung an die für die Risikoanalyse Erdbeben entwickelte Vorgehensweise wird überprüft, inwieweit methodische Grundlagen übernommen werden können bzw. modifiziert werden müssen, und welche Kenngrößen aus Datenerhebungen abzuleiten sind. Dabei wird neben der Hochwassereinwirkung in Form der Überflutungshöhe als wesentliche Neuerung der Einfluß der Bauwerksparameter berücksichtigt. Die Bauweisen sind danach in Verletzbarkeitsklassen einzuordnen, denen einwirkungsabhängig charakteristische strukturelle Schäden bzw. Durchfeuchtungsgrade zugewiesen werden können, die letztlich auch die Höhe des Schadens (Kosten) bestimmen. Wie anhand der Fallstudie Eilenburg gezeigt werden kann, können mit dem gewählte Ansatz für ein vorgegebenes Szenarium Gebiete mit besonders verletzbarer Bauwerksstruktur identifiziert und Empfehlungen für künftige Bebauung abgeleitet werden. Ein Schlüsselelement in der Vorgehensweise liegt in der Aufbereitung der erforderlichen bzw. geeigneten Datenebenen, die über Schadensfunktionen zu verknüpfen sind. Der Beitrag gibt eine Übersicht zu den Vorgehensweisen im mesoskaligen und mikroskaligen Betrachtungsmaßstab. Wie am Beispiel der Stadt Eilenburg gezeigt wird, können mit den bereitgestellten ingenieurmäßigen Hilfsmitteln und Datenebenen die aufgetretenen Schäden durch das Hochwasser 2002 in ihrer Höhe und Verteilung reinterpretiert werden. Assessment of damage due to flood impact: the case study of Eilenburg. Estimating damage caused by flood impact is an important, yet scientifically and methodically insufficiently investigated task, which is necessary for preparing the management of catastrophes. Alluding to the procedure developed in the risk analysis of earthquakes it is checked, whether methodical fundamentals can be transferred or have to be modified, and which parameters must be derived from data surveys. As an essential improvement, in addition to the inundation level, the influence of the buildings' parameters are considered. Subsequently, the building types are sorted into vulnerability classes, to which characteristic structural damages, depending on the impact, or humidity penetration ratios can be assigned, which ultimately determine the extent of the damage and the resulting cost. As can be shown for the case study of Eilenburg, areas with unusually high vulnerability of the building stock can be identified by applying the chosen approach assuming a defined scenario, leading to recommendations for future decisions on building in the area. A key element of the procedure lies in the preparation of the required or, respectively, usable data, which must be linked by damage functions. The paper gives an overview of the approaches for observations on mesoscale and microscale. As can be shown on the example of the town Eilenburg, with the provided tools and data, the damages caused by the flood in August 2002 can be reinterpreted regarding their height and distribution. [source]

El Niño Southern Oscillation link to the Blue Nile River Basin hydrology

HYDROLOGICAL PROCESSES, Issue 26 2009
Wossenu Abtew
Abstract The objective of this study is to evaluate the relationships of El Niño Southern Oscillation (ENSO) indices and the Blue Nile River Basin hydrology using a new approach that tracks cumulative ENSO indices. The results of this study can be applied for water resources management decision making to mitigate drought or flood impacts with a lead time of at least few months. ENSO tracking and forecasting is relatively easier than predicting hydrology. ENSO teleconnections to the Blue Nile River Basin hydrology were evaluated using spatial average basin rainfall and Blue Nile flows at Bahir Dar, Ethiopia. The ENSO indices were sea surface temperature (SST) anomalies in region Niño 3·4 and the Southern Oscillation Index (SOI). The analysis indicates that the Upper Blue Nile Basin rainfall and flows are teleconnected to the ENSO indices. Based on event correspondence and correlation analysis, high rainfall and high flows are likely to occur during La Niña years and dry years are likely to occur during El Niño years at a confidence level of 90%. Extreme dry and wet years are very likely to correspond with ENSO events as given above. The great Ethiopian famine of 1888,1892 corresponds to one of the strongest El Niño years, 1888. The recent drought years in Ethiopia correspond to strong El Niño years and wet years correspond to La Niña years. In this paper, a new approach is proposed on how to classify the strength of ENSO events by tracking consecutive monthly events through a year. A cumulative SST index value of ,5 and cumulative SOI value of , ,7 indicate strong El Niño. A cumulative SST index value of ,,5 and cumulative SOI index of ,7 indicate strong La Niña. Copyright © 2009 John Wiley & Sons, Ltd. [source]

Challenges in urban flood management: travelling across spatial and temporal scales

JOURNAL OF FLOOD RISK MANAGEMENT, Issue 2 2008
C. Zevenbergen
Abstract Urban floods cannot be managed in isolation at the city scale and responses to potential flood impacts are complicated by interlinked political, socio-economic and environmental changes. To understand the unique features of urban flood management, a framework should be developed in which spatio-temporal relations are further defined and investigated. This should provide clarity regarding both the feedback loops that cause vulnerability as well as those that build resilience, and how they interact across differing spatial scales. Various insights and methods from system and complexity theory could provide hands-on methods to create such a framework. Yet the transition towards system-based approaches is still surrounded by many unknown factors; more effort should be put into developing a roadmap towards this transition. It is argued that local-scale pioneering and experimentation are essential in this process to encourage the cultivation of resilience through bottom-up initiatives that can shape strategy and policy development. [source]