Flood Forecasting and Warning – a retrospective

Chris Haggett has worked in the UK water industry for over 40 years, including with the Greater London Council (Department of Public Health Engineering), Thames Water (Rivers Division), National Rivers Authority, Environment Agency and RAB Consultants. He has experience in hydrology, flood forecasting and warning, emergency management, and benefits and business change management. Chris has worked as Flood Forecasting and Warning Development Manager within the Environment Agency’s National Flood Warning Centre, and has experience in managing many major flood incidents, including Easter 1998, Autumn 2000 and Summer 2007 floods, at both a regional and national level. Chris has also worked as a Flood Warning Manager and was responsible for delivering the day-to-day flood forecasting and warning service for the Thames catchment. Chris looks back at four decades of development in flood forecasting and warning.

I started work as a graduate hydrometric assistant working for the Greater London Council (GLC), Rivers Division in 1975. My first job was assisting with the aftermath of the Hampstead Storm when 170.8mm of rain fell in just 155 minutes on 14 August 1975 (Keers and Wescott, 1976). One man died in the storm, four of London’s main-line railway stations were flooded and closed, a large part of the London Underground was brought to a standstill as tunnels were inundated and the electricity supply failed (figure 1). Within 5 minutes of the start of the storm over a hundred homes were flooded to more than a metre. And yet just 6km or so away from the storm centre, there was almost no rain at all.

This storm highlighted a number of fundamental issues including summer storms in urban areas can be destructive and life threatening; they are difficult to detect, even with a dense network of recording rain-gauges; they are challenging to forecast and almost impossible to warn against due to very short lead times.

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In 1977, another severe storm affected north-west London when a maximum of 113mm of rain fell in a 9-hour period at Ruislip, Middlesex (below). No deaths were reported but some 1,100 houses, 20 factories, 20 shops, several schools and churches, many roads and several railways were flooded to depths of up to 1.5m (Haggett, 1980). Although a rudimentary flood warning scheme was in place at the time, a Government inquiry highlighted that the system was not effective in giving any warning to the police or the public (Prickett, 1978).

The Prickett Report made several important recommendations to improve flood forecasting and warning for fast responding urban floods:

  • Flood detection and forecasting: information from detection gauges needs to be captured by a central processing unit with facilities for automatic interrogation and the issue of alerts to duty staff; the prospects for measuring and forecasting the location, duration and intensity of summer storms sufficiently for warning purposes could be improved with the aid of weather radar.
  • Flood warning dissemination: the most feasible method for alerting householders is for messages to be conveyed to nominated persons or flood wardens who would undertake to inform their neighbours; to be effective in the short time available, some river alarms might need to go direct to occupants or via flood wardens. Local audible warnings may be the only possibility in some situations.
  • Emergency management and public awareness: the operational arrangements should be clearly documented including objectives, equipment, communications, staffing, duties and duty rosters; occupants of property in flood susceptible areas should be regularly reminded of the warning arrangements and action which can be taken to minimise damage including flood proofing methods and other forms of self-help.
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Flooding from the River Brent, Ealing, London, August 1977

It is interesting to see how these recommendations have been acted upon and what improvements have been made to flood forecasting and warning in urban areas in the 40 years since these devastating storms in London in the 1970s.

Advances in Flood Detection, Forecasting and Warning in the 1980s and 1990s

Flood Detection. Following the storms and floods of the 1970s and early 1980s, there was a great emphasis placed on developing an integrated flood detection, forecasting and warning system for fluvial rivers draining Greater London. The resultant CASCADE system (a Catchment Assessment System Concerned with the Accurate Dissemination of Effective flood warnings) included a large element of automation, was simple to operate, reliable and accessible to users 24 hours a day. The design and operation of this system was carefully planned as the nature of catchments involved meant that there is often very little time for the issue of a warning before the onset of flooding.

Figure3

2km radar image of the “Lewisham Storm” of 10 June 1997

Initially, CASCADE incorporated data from a network of telemetered rain and river level gauges and from the London Weather Radar at Chenies. To facilitate the detection of localised urban storms 2km radar data displays were created which updated every 5 minutes (above). At the time, the Met Office did not routinely disseminate 2km radar data to users.

In the 1980s and 1990s disparate telemetry systems were in operation and progress was made to link, integrate and extend these systems, allowing operational access to any individual outstation via regional computer systems. At the same time, comprehensive alarm handling software was developed to alert duty staff of a developing situation based either on pre-defined rainfall intensities or river levels. Telemetry data displays allowed duty staff to rapidly assimilate near real-time information and this facilitated operational decision making (below).

Figure 4

Hyetogram/Hydrograph of the “Edgware Flood” of 22 September 1992

Although weather radar provided an unparalleled source of information on rainfall variations over urban areas, the accuracy of the rainfall estimates was on occasions poor and it was clear that improved calibration was needed. In the late 1980s an operational calibration technique was developed which made use of data from the London Weather Radar and a network of telemetered rain gauges to provide more accurate estimates of spatial rainfall. It was demonstrated that this technique provided a 22% improvement in accuracy relative to that obtained by radar data without calibration (Moore, et al., 1989a).

Flood Forecasting. Despite the importance placed on developing effective flood detection systems, it was soon recognised that to improve warning lead times further, more emphasis would be needed on introducing operational forecasting methods (Haggett et al., 1993 & 1995). This involves the prediction of rainfall, river levels and river flows to forecast the time of occurrence and duration of a flood. Methods of achieving this varied in technical complexity from rudimentary correlation techniques to sophisticated mathematical models capable of predicting rainfall, in-bank flows and flood plain inundation. For fast responding urban catchments development work focussed on applying rainfall forecasting and rainfall/runoff forecasting techniques.

In the 1990s, three approaches to quantitative rainfall forecasting were evaluated operationally:

  • FRONTIERS/NIMROD – making use of data generated by the Met Office giving rainfall forecasts out to 6 hours ahead on a 5km grid, updated every 15 minutes (Golding, 1994);
  • Local Radar Rainfall Forecasting – regional based systems providing forecasts up to 2 hours ahead on a 2km grid, updated every 15 minutes;
  • Convective Storm Forecasting (GANDOLF) – a system for generating automated nowcasts of convective precipitation (Collier, et al., 1994a).

Although FRONTIERS rainfall forecasts were very useful for flood forecasting, the technique did not fully meet the specific operational requirements needed for fast responding catchments. This prompted the development of a local rainfall forecasting system producing higher resolution forecasts. It was found that the local forecasting procedure achieved a superior performance to FRONTIERS up to 2 hours ahead (Moore et al., 1992). However, beyond lead times of two hours the utility of the local system, which is based on a single radar, is reduced as the radar field is advected beyond the area of interest (below).

Figure 5

Local Radar Rainfall Forecast Sequence for 14.00 to 16.00 GMT on 30 September 1993

As May (1994) demonstrated, both FRONTIERS and the Local Forecasting Technique had difficulties in forecasting in convective situations under certain circumstances. Where there is rapid storm development and erratic motion, for instance, both procedures failed to produce credible predictions. As the Hampstead Storm demonstrates, serious flooding incidents can be generated from convective storms which develop rapidly and become stationary over a location for a period. This prompted development work by the Met Office on the GANDOLF system based on an object-oriented convective precipitation model designed to exploit the predictive capabilities of a conceptual model of convective cell evolution (Pierce, et al., 2000).

In the 1990s much work was devoted to developing, calibrating and implementing rainfall-runoff models which made use of data from rain gauge networks, weather radar and short-period rainfall forecasting models. Studies were commissioned to assess the different rainfall/runoff model types, real-time updating methods and the effects of data time interval and spatial resolution. A study in the Thames catchment (Moore, 1993), showed that the Local Radar Rainfall forecasting scheme applied to locally calibrated radar data provided the best performance overall especially in small catchments. It illustrated that the simpler rainfall/runoff models had difficulty producing credible forecasts in catchments with complex responses.

Following studies of this type, decisions were made to use the more complex conceptual models for forecasting and to integrate them with operational detection and forecasting systems such as CASCADE. This led to the development of automated flood forecasting systems which ran every 15 minutes with new data and auto selection of the appropriate rainfall forecast or combination of rainfall forecasts for given circumstances.

Flood Warning. Despite the progressive improvement of detection and forecasting capability in the 1980s and 90s, flood warning failures continued. As Parker (1987) observed, this was often due to weaknesses in the dissemination phase of the process upon which the efficacy of the entire forecasting and warning system rests.

In England and Wales, the traditional method of disseminating flood warnings via the police and local authorities was becoming strained due mainly to resource constraints and the lack of clarity on mandatory responsibilities for warning dissemination. Consequently, a number of initiatives were instigated to improve the effectiveness of this important part of the flood warning process: automation of warning dissemination to the agencies; identification of areas of flood risk and better targeting of warnings; the use of flood wardens; the use of the media.

Figure 55

Flood Warning Dissemination System for the Colne Catchment (1994)

An example of warning automation can be afforded in the Thames Region where the fluvial Thames and each of its tributaries were divided into operational flood warning reaches. By nominating a specific reach or group of reaches, the duty officer was able to trigger the automatic creation and issue of warning notices to relevant agencies via telex and fax. This computer-controlled facility radically reduced the amount of time needed to generate warning messages to the emergency services, local authorities and utility agencies (above), (Haggett, 1995).

To improve the targeting of flood warning messages within each of the flood warning reaches, records stretching back to 1965 were collated and attributed to each reach. Information including property details, frequency of flooding and the level of flood risk was supplied to each police force and local authority in the Thames Catchment. It was hoped that armed with this information, the agencies would be able to target their resources more effectively during flooding incidents.

Several flood warden schemes were established in fast responding river catchments in and around Greater London where traditional dissemination methods failed to respond in sufficient time to be effective. In the early 1980s the GLC introduced the “watchdog” scheme at 22 high-risk locations where river level warning devices were installed which automatically alerted local authorities and residents when pre-defined levels were exceeded. Recipients of an alert monitored river levels locally and warned their neighbours of impending flooding. The scheme had mixed success with technological problems causing large numbers of false alarms to be generated in the early stages. In areas where the number of subsequent flooding incidents was low, the level of public interest soon waned and in some localities the scheme was withdrawn due to lack of support. Nevertheless, the scheme did signal a turning point, for the first time an attempt was being made to address the issue of flood warning dissemination for fast responding rivers in London by installing systems that would alert the public directly (Haggett, 1997).

There was also a conscious effort to involve the media in flood warning dissemination. Notices were passed to local radio stations for immediate broadcast during times of flood which identified the areas at risk. Advice and situation updates were given throughout an event via live and recorded interviews on radio and television and through the press. It was recognised at the time that the media would feature more extensively in flood warning dissemination in future years.

Research undertaken by Middlesex University in the 1980s and 90s showed that the passing of warning messages to the police and local authorities was very effective. However, these warnings often failed to reach the at-risk public in time for action to be taken to reduce flood losses. The research recommended that improvements should be made to the effectiveness of warning dissemination and that a multi-route approach should be developed involving a range of techniques that should work in parallel to ensure that the warning message reaches its intended target. (Hyde, 1992), (Fordham and Haggett, 1994).

Advances in Flood Detection, Forecasting and Warning from 2000

Flood Detection. Major UK floods over the last two decades have motivated significant technological and scientific advances in operational flood forecasting and warning.

The telemetered networks of river and rain gauges have been extended and integrated further, within and across government agencies. Access to data from such networks in near real time has been made publicly available for the first time.

The Environment Agency, for example, has extended its river level monitoring service to cover 36,000 kilometres of rivers in England. In addition, the Agency has approximately 1,000 real time rain gauges which are connected by telemetry and the data from some gauges is combined with data from the Met Office’s network to operationally calibrate rainfall radar data to improve accuracy.

Data from river level and rain gauge networks are published openly on the internet as it has the potential for a wide range of uses externally such as flood forecasting, farming, and recreation; flood forecasts are also being trialled online.

The weather radar network now consists of 15 operational radars across the UK providing real-time information to help monitor and forecast heavy rainfall (figure 8). In 2016, the Met Office and the Environment Agency launched the network renewal project which will provide major investment and improvements in new weather radar systems. The latest technology will be used to increase radar capability, such as dual polarisation which will improve quality control and rainfall rate accuracy. This investment will extend the operational life of the network by a further 15-20 years.

New technologies are being adopted more widely that allow incident staff to see what’s happening on the ground and to respond faster and better when floods threaten. This includes the use of mobile technology and mapping systems to facilitate the capture and sharing of real-time data.

Flood Forecasting. One of the major changes in flood forecasting during this period was the establishment in 2009 of the national Flood Forecasting Centre (FFC), a partnership between the Environment Agency and the Met Office. The FFC, for the first time, brought together the experts who predict the weather with those who forecast floods. This has led to the production of a daily, national Flood Guidance Statement (FGS) to the emergency response community.

The FGS is based on a Flood Risk Matrix approach that is a function of potential impact severity and likelihood. It has driven an increased demand for robust, accurate and timely forecast and alert information on fluvial and surface water flooding along with impact assessments. The Grid-to-Grid (G2G) distributed hydrological model has been employed across England, Scotland and Wales at a 1km resolution to support the FGS.

At a more local level, there was a move to bring together regional systems into a single national system to improve forecasting consistency across the country. The National Flood Forecasting System (NFFS) provided a single software shell capable of using a standard set of models that improved forecast quality and allowed extension of the service.

Flood Warning. Floodline Warnings Direct (FWD) was deployed in 2006 to replace and enhance legacy warning systems. There was a requirement to deliver a single, consolidated and robust national solution for warning and informing the public of flooding. Using the latest technology, warnings were targeted more effectively increasing the number of people receiving appropriate and timely warnings (Haggett, 2015).

FWD is the first integrated multi-media warning system deployed in the UK and it can now warn 1.2m people of risk of flooding at the touch of a button. The number of communication channels has steadily increased as social media grows and in December 2013 Twitter was used for the first time to send a severe flood warning.

Conclusions

Over the last 40 years there have been huge strides taken to develop the various elements of the flood forecasting and warning process. Improved flood detection using telemetry, weather radar and computer technology; enhanced forecasting using operational flow prediction models and quantitative rainfall forecasting techniques; more effective warning dissemination using computer technology to target warnings directly to the public; and timely, efficient and coordinated response by the relevant agencies. However, it is important to remember that flood forecasting and warning systems work on the principle of reducing flood losses through effective action by those at risk prior to a flood. To do this effectively all elements of the process must operate smoothly and in an integrated way to have any significant impact on flood losses. To deliver accurate, reliable and timely flood warnings the total warning system must operate efficiently.

Technology has played and is continuing to play an important role in integrating the total warning system, but there is a need to ensure that the service does not become technology driven. Other factors need to be considered which influence the performance and integration of flood warning systems, such as coordinated institutional arrangements, the flow of information and knowledge between organisations and communities, and human interaction and expertise.

References

Collier, C.G, Walsh, P.D. and Haggett, C.M. (1994a). The use of radar-based rainfall forecasts in operational flood warning. In: Merriman, P.A. and Browitt, C.W.A. (eds) Natural Disasters: Protecting Vulnerable Communities, Thomas Telford, London, 210-224.

Fordham, M. H. and Haggett, C. M. (1994). Flood forecasting, warning and response systems: the problem of warning dissemination. Workshop on Integrated Radar Estimates of Rainfall in Real-time Flood Forecasting. 25-26 July 1994, Monselice, Italy.

Golding, B.W. (1994). NIMROD and its relevance to the NRA. Internal Report. Restricted circulation.

Haggett, C.M. (1980). Severe storm in the London area – 16/17 August 1977. Weather. 35: 2-11

Haggett, C.M., May, B.C. and Crees, M. A. (1993). Advances in Operational Flood Forecasting in London. Proceedings of the Second International Symposium on Hydrological Applications of Weather Radar. Hannover, 7-10 September 1992.

Haggett, C.M., (1995). Operational fluvial flood forecasting and warning in the Thames Catchment. BHS Occasional Paper No.5. British Hydrological Society.

Haggett, C.M. (1997). Aims and objectives of flood warnings from the perspective of the flood forecaster, in Handmer, J.W. Flood Warnings: Issues and Practice in Total System Design. London: Middlesex University, Flood Hazard Research Centre.

Haggett C.M. (1998). An integrated approach to flood forecasting and warning in England and Wales. Journal of the Chartered Institution of Water and Environmental Management. 12: 425–432.

Haggett, C.M. (2015). Advances in Flood Warning Dissemination and the Challenges for Flood Forecasting. Real Time Flood Forecasting – Developments and Opportunities. Institution of Civil Engineers.

Hyde, V. M. (1992). The flood warning systems and flood-events of two catchments within the Eastern Area of the NRA. Thames Region. London: Middlesex University, Flood Hazard Research Centre,

Keers, J.F. and Wescott, P. (1976). The Hampstead Storm – 14 August 1975. Weather. 31: 2-16.

May, B.N. (1994). Integration of radar-based forecasting methods into CASCADE flood forecasting and warning system. COST-75 Seminar 1994, Brussels.

Moore, R.J., Watson, B.C., Jones, D.A., Black, K.B., Haggett, C.M., Crees, M.A., Richards, C.I. (1989a). Towards an improved system for weather radar calibration and rainfall forecasting using rain gauge data from a regional telemetry network. New directions for surface water modelling, IAHS Publication No. 181. International Association of Hydrological Sciences, pp13-21.

Moore, R.J., Austin, R.M., Jones, D.A. and Black, K.B. (1992). London Weather Radar Local Rainfall Forecasting Study: Final Report. Contract Report to the National Rivers Authority, Thames Region, Institute of Hydrology, September 1991, 124.

Moore, R.J., Austin, R.M., Carrington, D.S. (1993). Evaluation of FRONTIERS and Local Radar Rainfall Forecasts for use in Flood Forecasting Models: Final Report. Contract Report to the National Rivers Authority, R&D Note 225.

Parker, D. J. (1987). ‘Flood warning dissemination: the British experience’, in Handmer, J. (ed) Flood Hazard Management: British and International Perspective. Geobooks, p 169-190

Parker, D.J. and Haggett, C., 2001. The development of flood warning technologies in England and Wales, Paper presented at the International Emergency and Disaster Management Conference (TIEMS), Oslo, Norway, June.

Pierce, C.E., Hardaker, P.J., Collier, C.J. and Haggett, C.M. (2000). GANDOLF: a system for generating automated nowcasts for convective precipitation. Royal Met. Soc., Meteorological Applications, 7: 341-360.

Prickett, C.N. (1978). Departmental investigation into flood warning arrangements in north-west London. Ministry of Agriculture, Fisheries and Food.

 

 

 

 

Serious Gaming for Flood Resilience

Robyn Shaw, an MSc Sustainability and Water Security research student, reflects on work to develop a serious game to help improve community flood resilience.

I am currently at the University of Dundee and as part of my course I had the pleasure to embark in a research in practice placement supporting the development of practical solutions for flood resilience.  The aim of my placement was: To develop a concept of a multi-participatory game based on reality for flood response and community flood resilience in Scotland which was fun to play.

Cascde event (picture by Cascade_net)

Civil Agency, Society and Climate ADaptation to Weather Extremes (CASCADE-NET) workshop at the University of Dundee. Source: CASCADE-NET

Serious games are interactive and fun educational tools which allow players to learn from experience in a safe environment. The niche of the game I was focussing on was learning and understanding the different channels of communication during a flood. My placement involved desk-based research, setting up and attending meetings with key individuals, for example a gaming expert, running workshops and shaping the concept of the game into a prototype.

Two workshops were held, one with flood experts with representatives from SEPA, Scottish Flood Forum and a Local Authority, and another with university research students. The concept of the serious game was played, and constructive feedback was received in a discussion to assist the development. This was analysed and eight key areas arose: name, aim, audience, timing, players, graphics, education and ethics. Alterations were made and the serious game, now known as FORECAsT, became a prototype and was successfully ran at a CASCADE-NET Emergency Response seminar.

The FORECAsT game was run to support a CASCADE-NET seminar on Civil Society and Emergency Response: conflicting discourses of dependency and empowerment, with over 40 attendees from multiple disciplines including the Scottish Government, academics, local councils, and flood experts. This was an amazing opportunity for myself and the game as it promoted integration of serious gaming as an educational tool into wider society. The attendees were grouped into a number of roles all involved in receiving flood forecasting information. The players had to decide who and how to respond and communicate with other players using post-it notes, and news headlines and social media messages.

Overall, there was a very positive response and it stimulated a lot of discussion around the topic ‘reducing dependency and enhancing empowerment’ which was the main question the game supported in the seminar. The player’s feedback highlighted that they really began to understand the different channels of communication from the perspectives of each role during flood response. They were challenged, educated and had fun acting out a real life situation but in a safe environment. This opportunity has given the game FORECAsT a great prospect, ready for the next stages of development.

Throughout the course of my placement I was given several unique opportunities and a vast amount of valuable experience which I highly appreciated. I was fortunate to have worked collaboratively with those trying to develop the game FORECAsT and I believe it definitely has the potential to be established into a functional game in the future. Overall, it was an exciting new project to work on and I learnt the importance of support from other colleagues and the main factor- to enjoy your job!

 

The 2007 Floods: ten years of thinking big and acting early

Russell Burton is an expert in flood risk and incident management, Managing Director of RAB Consultants and a former flood warning team leader in the Environment Agency.  Russell looks back at changes in flood resilience since the 2007 floods.

I read John Curtin’s blog Flood risk management 10 years on – a journey of high and low tech improvements with great interest this week and found the list of improvements and the progress made impressive, especially against a backdrop of economic uncertainty and austerity.

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Tewkesbury is situated in Gloucestershire and was one of the worst affected parts of the county when the floods hit in July 2007. Source: Panoramio

It also got me thinking back to my own experiences and how the changes are not only in the tech we use but also in the way we think and respond to floods. Like John, I have my own story of what I was doing on the day of the 2007 storm. In July 2007, RAB was one year old, so it was a time of optimism and hard work for me to get the company off the ground. On that day in July I had a meeting with Environment Agency Wales (remember them!) in Cardiff, to start planning a flood exercise of all things. I planned to drive from Lichfield to Cardiff via the M50 with RAB’s first ever employee as a passenger. To be fair the Met office issued severe weather warnings for the west midlands up to 2 or 3 days ahead of the storm but it would only be on the homeward journey for us and who was to say it would be that bad and in that location anyway? I blush at the thought of my gung-ho attitude but I think I reflect the mindset of the times, “Think maybe, act if we have to”.

So off we set and had a great meeting, but by the time we were heading home reports were already coming in of flooding and travel disruption. Nevertheless we made pretty good progress on the M50 till we were approaching the junction with the M5 at Stroud. By now the downpour was a monsoon, the motorway came to a standstill and gradually the road became a river as torrents of water flowed off the fields. The hard shoulder and lane one were impassable but after a two hour delay we were able to crawl past in the “fast lane”.

Motorway 2007

Strensham Services on the M5, July 20th 2007. Source: flickr

To be fair I wasn’t the only one “thinking maybe and acting if we have to”, at some point I probably passed the lorry full of flood barriers bound for Upton upon Severn but stuck on the other carriageway of the flooded M5.

So what’s changed? Personally, I take Severe Weather Warnings very seriously now and adjust my travel arrangements to suit. But 2007 was also a watershed in mindset for flood risk managers in the UK. For the Environment Agency, it was the birth of the mantra “Think Big, Act Early”. This simple phrase has stood up to challenge (Think big, Act Appropriately was one watered down suggestion I recall) and I believe it’s helped drive the high and low tech improvements listed by John. It’s made us ask questions like, how big, how shall we act and when is early enough? The Flood Forecasting Centre  quantify the scale and timing of the impacts through the Flood Guidance Statement, which now gives flood managers up to 5 days notice to decide how and when to act early. The new extended flood outlook offers a 30 day window for flood risk managers to prepare and plan the response. The 2013-14 floods (amongst others!) highlighted that Thinking Big didn’t always result in Act Early. There was a need to plan what early actions could be done with this extra lead time for unprotected communities, and so came Temporary Defence Deployment Plans and Major Incident Plans to set out the strategic and tactical actions flood managers have at their disposal. Although these are just a couple of examples, the other improvements in John’s list are also driven by the need to “Think Big, Act Early”.

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July 2007 floods at-a-glance. Source: BBC

So in summary, the high and low tech improvements that have been made over the last 10 years are all fantastic but for me the biggest change is in our mindset, to “Think Big, Act Early”. To bring this into sharp contrast, this week the Met Office predicted that Britain is heading for “unprecedented” winter rainfall after their new super computer predicted records will be broken by up to 30 per cent. Time to “Think Big, Act early”.

Forecasting and hazard early warning systems: international perspectives

Canada recently witnessed severe flooding with some river flows reporting their highest on record.  Whether this is becoming the norm or not following recent flood-rich years, delivering effective multi-hazard early warning systems is vital for enabling communities being prepared for future events.  The Sendai Framework for Disaster Risk Reduction, which was endorsed by the United Nations, encourages government agencies to support improved and effective early warning systems. So, how are agencies responding to such challenges of early warning for increased natural hazards?

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A man fixes a hose connected to a pump at his flooded house on Ile Bizard, Que., near Montreal, Monday, May 8, 2017. Source: Paul Chiasson/The Canadian Press

The European Geosciences Union General Assembly which took place between 23rd and 28th April in Vienna, was an opportunity to share progress and innovations in the field of forecasting and warning systems.  One PICO session brought together presentations on real-world case studies of system implementations, configured at local, regional, and national scales.

On emerging capabilities, Mikuličková presented on approaches to trans-boundary flood forecasting in Slovakia, where European scale predictions (EFAS) run alongside a local model.  Likewise, in Nepal, global predictions (GloFAS) are used in conjunction with regional Data-Based Mechanistic Modelling (DBM) techniques for community alerting.

Flood Outlook

The new flood outlook product for England and Wales. Source: Flood Forecasting Centre, Exeter.

Various approaches to flood outlooks were presented.  Pilling presented new methods for providing flood risk guidance for the month ahead in England and Wales which have been developed in response to the Winter 2015/16 floods. Thiemig presented the latest developments with the European Flood Awareness System (EFAS) which include seasonal outlooks, event hazard mapping and rapid risk assessments. 

For those that have no experience of running an operational flood forecasting system, the opportunity was provided to test yourself through the interactive game for pathways to designing and running an operational flood forecasting system.  This follows a series of interactive games developed by the HEPEX community over recent years at the EGU General Assembly.

PICO session

EGU PICO session on operational forecasting and warning systems for natural hazards: challenges and innovation.

Away from the PICO session, several other talks provided some insights into global approaches in flood forecasting.  Demargne presented work in France on hydrologic ensembles based on convection-permitting precipitation nowcasts for flash flood warning.  The new system, called Vigicrues Flash, follows major flooding which occurred in France in 2010 resulting in 24 casualties and 1350 people being evacuated.  Parry presented work on data availability, limitations, and the impact of observational uncertainty for operational flood forecasting in Scotland. Finally, Dottori gave an interesting talk on satellites, tweets, forecasts and the future of flood disaster management where the use of social media is being trialled to verify flood forecasting where no data exists.

For more information on our EGU presentation on research with the University of Dundee and SEPA, please read the recent HEPEX article on ‘public perceptions of flood warnings in Scotland.