Recent changes in flood management policy towards more distributed, holistic management has seen management responsibility increasingly transferred downwards onto those at risk, with a concomitant increase in policies intended to promote active public participation in flood management. However, active participation in flood management remains elusive, with established, expert-led practices of management still pre-eminent in many areas.
The multi-dimensional perspectives on flood risk project challenge existing practices in flood risk management through the adoption of novel participatory approaches to exploring issues traditionally considered to be expert-led. Working together with communities in the Twizell Burn catchment in the northeast of England, the research looks to explore how current practices of catchment management are shaped by competing frames of knowledge regarding citizen participation. Building upon this understanding of the current practice, the research also explores how participatory approaches can open up and enhance existing practices of flood management. At Corbridge in the Tyne Catchment in the northeast of England, working together with a flood-affected community the research explores how local knowledge can be used to enhance the validation of complex numerical flood models. Builds upon novel participatory research approaches pioneered at Durham University, it also works together with flood victims to explore how flood risk is communicated. Opening up the discussion of what information is important to whom and why using in-depth participatory techniques reveals the limitations of our current communications and allows the development of new approaches which more effectively act to promote local resilience to future floods.
Flooding is a major hazard in England, potentially affecting over 5 million properties. Climate change is predicted to increase the risks posed by flooding in the future. There is an urgent need to integrate people living at risk from flooding into flood management approaches, encouraging flood resilience and the up-take of resilient, pre-flood activities. The effective communication of flood risk information plays a major role in providing the information necessary for those at-risk to make decisions about flood risk and prepare for future floods.
This research, currently being carried out by Durham and Newcastle universities in Corbridge, explores how flood risk communications could be undertaken more effectively, based on the perspectives of those at risk from floods. The research finds that current approaches to real-time flood risk communication fail to forecast the likely significance of predicted floods, whilst current passive approaches to flood mapping lack detailed information about how floods occur, or use confusing scientific terminology which people at risk find difficult to relate to the realities of flooding on the ground. This means users do not have information in a format they find useful to make informed decisions about how to prepare for and respond to future floods.
Working together with at-risk participants as part of the Corbridge Flood Research Group, the research has co-produced new approaches for communicating flood risk. These approaches focus on providing detailed information on past floods, helping people to contextualise past flood experiences and to understand how and why their area floods. This helps them to understand their risk and take appropriate pre-flood actions, such as preparing a flood plan or identifying key belongings to move to safety. These approaches also focus on providing forecasts of predicted flooding and allow those at risk to explore catchment wide information, allowing them to assess the significance of predicted flooding and make more informed judgments on what action to take when flooding is predicted.
The figures presented below show the new approaches that have been co-produced by the Corbridge Flood Research Group. Click on the figures to view a high resolution version.
The graphics presented in this section are mock-ups of potential options for alternative, online flood risk communications. Actual implementation would require additional engagement with end-users to ensure that interactive functionality was effective and properly integrated. However, the graphics have been designed to be as realistic as possible by using readily available information and drawing on current industry or academic approaches to assessing flood risk. The information used of the maps is summarised below.
Ordnance Survey Mapping
The Ordnance Survey Mapping used for the graphics is Ordnance Survey Open Data and is freely available even for commercial usage. Other examples of online flood mapping have made use of Google Maps or Bing Maps background mapping . Flood Depths and Flood Dynamics
The flood depth and dynamics information presented on Figure 4 represented estimated maximum flood depths during the December 4/5 2015 flood event. These depths have been generated by a flood inundation model constructed using the Lisflood-fp modelling package1. The model outputs, including the key flood mechanisms and dynamics, have been validated using information collected from the community as part of the research process.
River Gauge Levels
The style of the river gauge level graphs presented on the graphics are copied from the existing style used by the current online gauge graphs.
The water levels on the graphs and the current river level states are synthetic for information only and do not represent an actual flooding event. The approach to river level forecasting is based on proposals made by Leedal et al2.
1 P.D Bates and A.P.J De Roo, ‘A Simple Raster-Based Model for Flood Inundation Simulation’, Journal of Hydrology 236, no. 1–2 (September 2000): 54–77, doi:10.1016/S0022-1694(00)00278-X. – see here.
2 D. Leedal et al., ‘A Data Based Mechanistic Real-Time Flood Forecasting Module for NFFS FEWS’, Hydrology and Earth System Sciences Discussions 9, no. 6 (8 June 2012): 7271–96, doi:10.5194/hessd-9-7271-2012.
Figure 01 – River Tyne catchment overview showing all water level gauges with their current status and the magnitude of any change
This map presents an overview of the Tyne catchment showing the gauges and their current water level status, as well as the status of any flood alerts currently in place. The size of the gauge icons indicates the rate of rise or fall of the water level. The design is based on a combination of the USGS Flood Inundation Mapper, which allows viewing of gauges at a country scale, and the Fishpal website, which provides a gauge state of rising, falling, or stable. However, whereas Fishpal provides only a tabulated list of gauges this would allow rapid visual assessment.
This view allows the user to quickly assess the state of water levels across the catchment, particularly about how quickly the river is responding to rainfall and how far downstream a flood wave has progressed.
The group considered this view to be very useful for providing an overview of the catchment and for assessing the significance of any rises in water levels. To enhance the information provided and to make it easier to interpret, hovering the mouse over individual gauges would provide a gauge location name and a current level. Clicking on individual gauges would open the gauge level view. Zooming in on this map would also show details of current flood warnings in place.
Figure 02 - The gauge dashboard showing the four options for live gauge graphs
This figure presents different options for the way that ‘live’ gauge information should be presented:
1. The current situation showing a five-day historic water level with maximum previous water level and 'flooding possible over' water levels
2. The current situation allowing the overlay of a past flood onto the five-day period; a past flood could also be the synthetic hydrograph for a significant flood, for example the 1% AEP event
3. The current situation with a water level predicted into the future including potential estimation error
4. The current situation allowing viewing of both the predicted water levels and the historic overlay
Several general comments were made by the group regarding the gauges.
Of the options presented, both the historic overlay and the predicted water levels were considered to be important, although viewing both of these on the same graph was considered too complex. The group considered the prediction and estimation error to be easily understandable if presented alongside explanatory information. However, the prediction timescale should be limited in time to maintain a reasonable margin of error, so as to avoid people writing off the prediction as meaningless. The historic view should allow different past events to be overlain so that different magnitudes of flooding could be examined.
Figure 03 - The detailed flood map showing key information about the flood mechanisms and dynamics for a past flood in an interactive fashion
This map presents a detailed 'account' of a past flood, showing modelled flood depths alongside information on specific flood dynamics, mechanisms and water flows. Clicking on different aspects of the map would provide detailed information on the dynamics of the flood, impacts, and any post-flood actions that might have altered the flood risk, for example flood defence works.
It also presents the recorded flood hydrograph, allowing the water levels to be interrogated. This would be linked to the different aspects of the map, highlighting key dynamics at different water levels, for example areas of overtopping activated at particular water levels on the rising limb of the hydrograph. The hydrograph would also overlay the current water level, which could be used to assess the present risk and how this compared to the past event.
The group considered the detail of the information on this map to be very useful in developing a deep understanding of the flood characteristics of their area, and a possible way of making people more familiar with water levels and the realities of flooding events. Another map was also presented alongside this one which showed only the flood depths; this second map was not considered to be as useful as it lacked the contextual information which explained the dynamics of the flood.
Figure 04 - The flood explorer simulator which allows the user to set different water levels and simulates the areas impacted and their estimated flood depths
This map links flood levels to areas potentially at risk from flooding by allowing the user to scroll the water level for a given area and identifying the extent and depth of potential flooding. It would also present the current gauge graph and predicted water levels, allowing the user to explore the potential impacts of predicted water levels.
The group considered this map to be very useful as a way of allowing them to assess the impacts of potential future flood levels. Although this map did not present possible areas of overtopping or flood dynamics, the group considered this unimportant when used in combination with the detailed information on past floods. The simplicity of this map made it more useful for using alongside the active information in the immediate pre-flood period, whereas the more detailed maps were for use in the longer-term planning phase.
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