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Abstract
Anticipatory actions are increasingly being taken before an extreme flood event to reduce the impacts on lives and livelihoods. Local contextualized information is required to support real-time local decisions on where and when to act and what anticipatory actions to take. This study defines an impact-based, early-warning trigger system that integrates flood forecasts with livelihood information, such as crop calendars, to target anticipatory actions better. We demonstrate the application of this trigger system using a flood case study from the Katakwi District in Uganda. First, we integrate information on the local crop cycles with the flood forecasts to define the impact-based trigger system. Second, we verify the impact-based system using historical flood impact information and then compare it with the existing hazard-based system in the context of humanitarian decisions. Study findings show that the impact-based trigger system has an improved probability of flood detection compared with the hazard-based system. There are fewer missed events in the impact-based system, while the trigger dates are similar in both systems. In a humanitarian context, the two systems trigger anticipatory actions at the same time. However, the impact-based trigger system can be further investigated in a different context (e.g., for livelihood protection) to assess the value of the local information. The impact-based system could also be a valuable tool to validate the existing hazard-based system, which builds more confidence in its use in informing anticipatory actions. The study findings, therefore, should open avenues for further dialogue on what the impact-based trigger system could mean within the broader forecast-based action landscape toward building the resilience of at-risk communities.

Discusses the results of evaluations of flood forecasting, warning
and response systems in England, Wales, Scotland and Northern Ireland.
Reveals that in England and Wales flood warning systems often
underperform. Despite technical sophistication and their elevation to
high priority in central government′s flood defence strategy,
arrangements for flood warnings are now under considerable stress
because of lack of agreement over organizational roles and
responsibilities. Legal ambiguities, funding difficulties and
ideological positions lie behind these problems. Flood warning systems
are developing in Scotland, and there is now a "fledgling"
system in Northern Ireland, but both lag behind England and Wales.
Examines implications for the future.

Publisher's version (útgefin grein) ; Glacier runoff and melt from volcanic and geothermal activity accumulates in glacier dammed lakes in glaciated areas around the world. These lakes eventually drain, creating hazardous subglacial floods that are usually only confirmed after they exit the glacier and reach local river systems, which can be many tens of kilometres from the flood source. Once in the river systems, they travel rapidly to populated areas. Such delayed detection represents a potentially lethal shortcoming in early-warning. Here we demonstrate how to advance early-warning potential through the analysis of four such floods in a glaciated region of Iceland. By comparing exceptional multidisciplinary hydrological, GPS and seismic ground vibration (tremor) data, we show that array analysis of seismic tremor can be used for early location and tracking of the subglacial flood front. Furthermore the timing and size of the impending flood can be estimated, prior to it entering the river system. Advanced warnings of between 20 to 34 hours are achieved for large (peak discharge of more than 3000 m3/s, accumulation time of ~ 5.25 years) to small floods (peak discharges from 210 to 380 m3/s, accumulation times of ~ 1.3 years) respectively. ; The data were collected and analyzed within the framework of FutureVolc, which received funding from the European Union's Seventh Programme for research, technological development and demonstration under grant agreement No. 308377. We thank Martin Möllhoff, Heiko Buxel for technical support, Tómas Jóhannesson for fruitful discussion, Benedikt G. Ófeigsson for assistance with GPS processing and Aoife Braiden and Vilhjálmur Kjartansson for assistance in the field. ; Peer Reviewed

Abstract. An early warning system (EWS) for flash floods has been developed for part of the Sinai peninsula of Egypt, an hyper-arid area confronted with limited availability of field data, limited understanding of the response of the wadi to rainfall, and a lack of correspondence between rainfall data and observed flash flood events. This paper shows that an EWS is not a "mission impossible" when confronted with large technical and scientific uncertainties and limited data availability. Firstly, the EWS has been developed and tested based on the best available information, this being quantitative data (field measurements, simulations and remote sensing images) complemented with qualitative "expert opinion" and local stakeholders' knowledge. Secondly, a set of essential parameters has been identified to be estimated or measured under data-poor conditions. These are: (1) an inventory of past significant rainfall and flash flood events, (2) the spatial and temporal distribution of the rainfall events and (3) transmission and infiltration losses and (4) thresholds for issuing warnings. Over a period of 30 yr (1979–2010), only 20 significant rain events have been measured. Nine of these resulted in a flash flood. Five flash floods were caused by regional storms and four by local convective storms. The results for the 2010 flash flood show that 90% of the total rainfall volume was lost to infiltration and transmission losses. Finally, it is discussed that the effectiveness of an EWS is only partially determined by technological performance. A strong institutional capacity is equally important, especially skilled staff to operate and maintain the system and clear communication pathways and emergency procedures in case of an upcoming disaster.

Recent flood events in Europe, the USA and elsewhere have shown the devastating impact that flooding can have on people and property. Flood warning and forecasting systems provide a well-established way to help to reduce the effects of flooding by allowing people to be evacuated from areas at risk, and for measures to be taken to reduce damage to property. With sufficient warning, temporary defences (sandbags, flood gates etc) can also be installed, and river control structures operated to mitigate the effects of flooding. Many countries and local authorities now operate some form of flood warning system, and the underlying technology requires knowledge across a range of technical areas, including rainfall and tidal detection systems, river and coastal flood forecasting models, flood warning dissemination systems, and emergency response procedures. This book provides a comprehensive account of the flood forecasting, warning and emergency response process, including techniques for predicting the development of flood events, and for issuing appropriate warnings. Related topics, such as telemetry and information systems, and flood warning economics, are also discussed. For perhaps the first time, this book brings together in a single volume the many strands of this interesting multidisciplinary topic, and will serve as a reference for researchers, policy makers and engineers. The material on meteorological, hydrological and coastal modelling and monitoring may also be of interest to a wider audience.

This paper addresses model design and data-related issues pertaining to the use of risk assessment models in support of conflict early warning systems. The paper first examines the data needed for risk assessment models. It argues that there are actually two types of data that we must collect and use: data to determine the theories that best explain the outbreak or escalation of violent conflict and data corresponding to variables that have been demonstrated to have predictive power and thus are appropriate for use in a risk assessment model. With respect to intrastate conflicts there remains a dearth of data of the first type that is only slowly being corrected. Collecting data of the second type will continue to be an inefficient process until better theories have been formulated and tested with the first type of data. The paper then examines a number of models germane to risk assessment and conflict early warning. It finds that except for one class of models, so-called correlational models, there has been only limited work done even though the alternatives appear to have promise. ; Das Papier behandelt Modellierungsfragen und Datenprobleme bezüglich der Zweckmäßigkeit sog. risk-assessment-Modelle bzw. zur Klärung von Frühwarnmodellen. Zunächst wird generell die Datenlage überprüft. Dabei läßt sich argumentieren, daß zwei Typen von Daten im Mittelpunkt stehen: einerseits Daten, die zur Erklärung des Auftretens und der Eskalation von gewaltsamen Konflikten herangezogen werden können, andererseits Daten, die sich für die Fundierung von risk-assessment-Modellen eignen. Während beim ersten Typus vor allem ein eklatanter Mangel bezüglich innerstaatlicher Konflikte herrscht, sind wir beim zweiten Typ mit dem Problem konfrontiert, daß das Generieren von immer neuen Daten solange ein wirkungsloses Unterfangen bleiben wird, wie es nicht mehr theoretische Klarheit über die Prozeß- und Strukturbedingungen von Gewalt gibt. Anschließend werden noch zentrale Modelle überprüft, die sich mit dem risk-assessment und der Frühwarnung befassen. Es wird gezeigt, daß – mit Ausnahme von Korrelationsmodellierungen – noch immer zuwenig Arbeit investiert wird, wenngleich die Alternativen durchaus vielversprechend sind.

Focuses on ways of coping with socio-economic and employment challenges of responding to crises arising from natural disaster, man-made catastrophe, or war. Reports on best practices and new avenues for crisis response and early warning, with examples from 14 developing countries around the world

Is it possible to see famines coming, to be prepared and to save possibly hundreds of thousands of lives? Or is this the wrong question? A famine is not a single natural catastrophe: it has different stages. Many societies have sophisticated strategies for coping - but these are becoming dramatically limited. Famine Early Warning System is about the people who are caught up in the process of famine. Peter Walker looks at how they perceive their predicament and what they do to avert mass starvation: and at what genuinely useful help can be offered in order to prevent irreversible disaster. Orig

Early warning systems (EWSs) are subject to restrictions that apply to exchange rates in general: fundamentals matter but their influence is small and unstable. Despite this limitation four major lessons emerge: First, EWSs have robust forecasting power and thus help policy-makers to prevent crises. Second, policy-makers must decide about some EWSs' elements, such as the sensitivity of the forecasts. Third, EWSs' performance is increased by taking a logit model, shorter samples and a regional approach. Fourth, the finding of contagion may motivate policy to shield its economy against inefficient international financial markets.