Dennis J. Parker

Floodplain development policy in England and Wales

Abstract There is evidence of substantial floodplain development in England and Wales. An ‘escalator effect’ is observed whereby progressively higher levels of flood defence are provided to protect against progressively increasing flood damage potential, caused mainly by post-defence development. The efficacy of current flood defence and floodplain planning policy is questioned. Planning influences floodplain development rather than prevents it. Wider planning constraints divert development towards floodplains to avoid other environmental problems. Floodplain development decisions should be taken in the context of the wider benefits of such development, as well as the natural and cultural functions of floodplains.

An evaluation of flood forecasting, warning and response systems in the European Union

This paper presents results from the EUROflood research project sponsored by the European Commission under the EPOCH programme. The paper evaluates levels of development of flood forecasting, warning and response systems (FFWRS) in the European Union with reference to riverine and tidal floods in The Netherlands, the United Kingdom, Germany, France and Portugal. An experimental evaluation methodology, comprising fourteen criteria and five development stages, is used to evaluated FFWRS. Flood forecasting is the starting point, but the research addresses entire FFWRS. Despite advances in flood forecasting, FFWRS often under-perform because warning dissemination and response are unsatisfactory.FFWRS have developed in response to different water resource management problems, varying flood characteristics and different historic, cultural and institutional factors. FFWRS for flood defence and flood emergency response are the main focus, but they are also important for navigation, bridge clearance, fishing, recreation and industry. France, parts of Germany, The Netherlands and England and Wales have relatively mature FFWRS. FFWRS are much less well developed in Scotland, Northern Ireland and Portugal, and important areas for enhancement are identified in all countries. Cross-country and within-country comparisons reveal the potential for knowledge transfer, although ultimately the unique circumstances of each country places limits upon this process.

Assessing multifaceted vulnerability and resilience in order to design risk-mitigation strategies

Vulnerability studies have evolved significantly in recent decades. Although not overly theoretical compared with some other fields of science, some important conceptual progress has been made. At the practical level, vulnerability indicators have been used either at a generic level or for particular hazard contexts. However, these indicators are often predictably too narrow in their coverage of aspects of vulnerability. An important need remains to produce more conceptually informed vulnerability indicators or parameters and more satisfactory operational tools to assess weaknesses and resilience in coping with natural risks. In this paper, we present the methodology developed in the context of a recently concluded EU funded project, ENSURE (Enhancing resilience of communities and territories facing natural and na-tech hazards). The resulting vulnerability and resilience assessment framework tool adopts a systemic approach embedding and integrating as much as possible the multifaceted and articulated nature of concepts such as vulnerability and resilience. The tool guides evaluators towards a comprehensive and context-related understanding of strengths and fragilities of a given territory and community with respect to natural extremes. In this paper, both the framework tool and its application to Sondrio in Italy, which is exposed to flash floods, are presented and discussed. The merits and demerits of the new tool are discussed, and the results of the application to Sondrio indicate where data are currently missing, suggesting the kind of data, which will need to be gathered in future to achieve more complete assessments. The results also suggest vulnerability reduction policies and actions and further ways of revising the existing framework tool in the future.

Risk communication in emergency response to a simulated extreme flood

Abstract Risk communication in flood incident management can be improved through developing hydrometeorological and engineering models used as tools for communicating risk between scientists and emergency management professionals. A range of such models and tools was evaluated by participating flood emergency managers during a 4-day, real-time simulation of an extreme event in the Thamesmead area in the Thames estuary close to London, England. Emergency managers have different communication needs and value new tools differently, but the indications are that a range of new tools could be beneficial in flood incident management. Provided they are communicated large model uncertainties are not necessarily unwelcome among flood emergency managers. Even so they are cautious about sharing the ownership of weather and flood modelling uncertainties.

New insights into the benefits of flood warnings: Results from a household survey in England and Wales

Abstract The flood defence agency in England and Wales has been pursuing a programme of flood warning system enhancement, engaging householders at risk in improving their warning responses. The immediate aim of this paper is to test and revise a model of economic benefits of warnings, but the survey data also generate insights into the constraints acting upon flood warning responses. Damage saving is less than previously anticipated: warning reliability and householder availability problems limit savings. Warnings are less likely to be received by those in lower social grades, and flood warning lead time is a factor in avoiding damage. The survey data indicate the complexities involved in improving flood warning response, and provide policy pointers.

Advances and challenges in flash flood warnings

Advances in meteorological, hydrological and engineering sciences are fast generating a range of new methodologies for forecasting weather and flood events, including ensemble prediction systems (EPS) and new hydrodynamic models. These advances are in addition to those already made in weather radar and quantitative precipitation forecasting which have enhanced flood warning lead time potential; in integrated real-time monitoring and modeling; and in long-term models. Each of these advances presents new challenges within the complex information and data flows which now exist between actors generating forecasts and actors using them (Fig. 1). At the same time, the natural, physical and engineering sciences, which are generating the technical advances noted above, are being challenged by social science. The social science paradigm focuses on human perceptions of risk information and the under-estimated complexities of communicating risk between actors, and stresses that uncertainty must be managed rather than eradicated. It has already contributed much to a broader and deeper understanding of human behaviour in the face of hazard warnings. It promises to contribute further in addressing the risk communication and response issues now raised by the new wave of technical advances.

The Fallibility of Flood Warning Chains: Can Europe’s Flood Warnings Be Effective?

Taking a broad overview, this paper explores recent evidence on flood forecasting, warning communication and public warning response in Europe between 1995 and 2010. Key flood warning chain deficiencies are identified together with the effect these deficiencies have on flood warning effectiveness and loss reduction. Europe-wide data on flood forecasting and warning communication are examined alongside recent in-depth research evidence from various parts of Europe on flood warning receipt, warning response and warning effectiveness. Using the latest flood warning benefit assessment methodologies, the results of case studies of flood loss avoidance through warnings reveal the damage saving potential of flood warning. Although these savings are significant, currently they are inhibited by a series of shortcomings which transfer through the warning chain limiting warning impact. Flood forecasting, warning and warning response systems are inherently fallible and so it is doubtful that they will ever be consistently effective. Sole reliance upon them to protect life and property carries inevitable risks and governments should not be surprised when flood warnings are only partially effective. Although Europe’s flood forecasting and warnings have been improving, the scope for further improvement is large. Extending flood forecasting and warning coverage, extending warning lead times by combining meteorological and hydrological forecasts, building greater redundancy into warning communication, and crucially also building it into cooperative strategies designed to engage at risk communities in flood warning response, are all likely to be important.

Assessing options for the development of surface water flood warning in England and Wales.

This paper explores the technical options for warning of surface water flooding in England and Wales and presents the results of an Environment Agency funded project. Following the extensive surface water flooding experienced in summer 2007 a rainfall threshold-based Extreme Rainfall Alert (ERA) was piloted by the Met Office and Environment Agency providing initial steps towards the establishment of a warning for some types of surface water flooding. The findings of this paper are based primarily on feedback on technical options from a range of professionals involved in flood forecasting and warning and flood risk management, about the current alerts and about the potential options for developing a more targeted surface water flood warning service. Providing surface water flooding warnings presents a set of technical, forecasting and warning challenges related to the rapid onset of flooding, the localised nature of the flooding, and the linking of rainfall and flood forecasts to flood likelihood and impact on the ground. Some examples of rainfall alerting and surface water flood warning services from other countries are evaluated, as well as a small number of recently implemented local services in England and Wales. Various potential options for implementation of a service are then explored and assessed. The paper concludes that development of a surface water flood warning service for England and Wales is feasible and is likely to be useful to emergency responders and operational agencies, although developing such a service for the pluvial components of this type of flooding is likely to be feasible sooner than for other components of surface water flooding such as that caused by sewers. A targeted surface water flood warning service could be developed for professional emergency responders in the first instance rather than for the public for whom such a service without further operational testing and piloting would be premature.

Modelling the potential damage-reducing benefits of flood warnings using European cases

Flood warning systems are now centre-stage in flood risk management strategies in Europe. This is due to advances in flood forecasting and the rapid communication of flood risk information, coupled with a growing understanding that communities need to find better ways of co-existing with rivers and the realization that structural flood defences are insufficient on their own to prevent flooding. However, not enough is known about the potential and actual benefits of flood warnings for avoiding property damages. This paper presents an extended approach to the estimation of potential flood damage reduction benefits of flood warnings for fluvial and tidal floods, drawing upon research completed for the European Commissions Floodsite project. Its aim is to demonstrate the potential economic benefits of coupling flood warnings to a combination of structural and non-structural flood risk management measures. Previous research in this area is critiqued, including that which suggests that flood warnings are futile, and the features, strengths and weaknesses of the extended approach are presented and discussed. Two case studies, a national-level (England and Wales) and a local-level (Grimma, southeastern Germany) assessment of flood damage-saving potential, are presented to illustrate the new approach. Although a number of data quality issues need addressing, the model outputs and estimations of potential damage savings may be used to make wise decisions about investment in flood warning systems, and to identify those areas, such as public flood risk awareness, that need attention to achieve the full scope of potential benefits in practice.

Flood warning systems under stress in the United Kingdom

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.