Flood Model
Infoterra Ltd and JBA Consulting have combined their expertise to bring new levels of intelligence to flood risk predictions, by developing a flood risk model of GB. This new model offers a unique tool for understanding flooding from rivers and sea, surface water flooding, groundwater and dam/reservoir breaks all at property level.
The JBA Comprehensive Flood Map Product is a good quality spatial dataset that provides users with Flood Map data for England, Wales and some of the major urban centres and rivers of Scotland.
Flood map data products currently available are:
- Surface Water Flood Map
- Reservoir Failure Flood Map
- Undefended River Flood Map
- Coastal Flood Map
A range of Height Data Products are used to create the the Flood Model: approximately 15,000 sq km of high accuracy urban centre LiDAR Digital Terrain Model data and 155,000sq km of photogrammetric 5m ground model data. A Product update is produced annually.
Surface Water Flood Map
JBA’s surface water flood map is the first available map in the UK to identify areas likely to flood following extreme rainfall events, i.e. land naturally vulnerable to surface water or “pluvial” flooding. The area covered is all of England and Wales plus major cities in Scotland.
The model provides the maximum depth of flooding in each 5m cell of the digital terrain model, which is processed into depth bands to identify varying levels of risk. This model is the world’s first large scale mapping of surface water risks and has been licensed by the Environment Agency for emergency planning purposes.
The maps include 4 bands indicating areas of increasing natural vulnerability to surface water flooding. These bands are obtained by extracting data based upon flooded depths of:
Less than 0.1m
0.1m (less likely to flood)
0.3m
1m or greater (more likely to flood)
These bands indicate those areas that will be more and less likely to flood as well as the relative depth of flooding.
Reservoir Failure Flood Map
JBA’s reservoir failure flood maps identify areas in England that are most likely to suffer damage to property following the sudden catastrophic failure of a reservoir. 1,700 reservoirs are included in the model. The maps are based on modelling that used empirical methods to predict water flow resulting from failure, which was then modelled on the 5m digital terrain models (DTM) using JBA’s advanced 2D hydraulic modelling techniques. These maps are the UK’s first large scale mapping of the risk from reservoir failure.
Undefended River Flood Map
JBA’s river flood map provides the highest resolution flood mapping available for urban areas that hold the highest aggregations of exposure for insurers. The modelled area includes over 120 cities in England Wales and Scotland for which LiDAR digital terrain data are available. The mapping is based on a detailed hydrological analysis of river systems, followed by advanced 2D hydraulic modelling of water flow onto river floodplain areas. The output from the modelling includes flood outlines and flood depth grids for the following four return periods: 1 in 75 years; 1 in 100 years; 1 in 200 years, and; 1 in 1,000 years.
Coastal Flood Map
JBA’s coastal flood map indicates land vulnerable to sea surge flooding in England and Wales. The coastal flood map was developed using sophisticated ocean circulation and storm surge models developed as part of the European Tidal Database project. The flood inundation model simulates how and where coastal flood water will move over the land. The horizontal level of resolution of the model is 5m.
The output includes flood outlines for four return periods: 1 in 75 years; 1 in 100 years; 1 in 200 years, and; 1 in 1,000 years.
The flood model has been produced in partnership with JBA consulting
