This wonderful RAF air-photograph, taken at about 11am on 15th December shows the Trent in full flood, with substantial overbank flooding affecting both the north and south of the river and the area to the south (Lockington Marshes) almost completely inundated. A south-bound express train can be seen, most visibly by its train of steam, about to cross the Trent. But how deep was the flooding. Some while ago we calculated the extent of the floods by comparing the photographic evidence with recent lidar terrain data.
Lidar Terrain Model.
"Flooded" lidar (in blue) superimposed on air-photograph.
Together, these two allow us to duplicate the photographically documented flooding by selective colouring of the lidar data. By our estimates the river level at Lockington was up to 1.2m above its usual winter level. So what about visualisation? Using Cityscape and the lidar DTM (exported as a binary grid from ArcGIS, which overcomes the GeoTiff issues) it is possible to flood the terrain to roughly duplicate the level of inundation of December 1954.
Floods of 1955 simulated in CityScape
Moving from the 2D map view CityScape allows some nice 3D visualisation of the extent and character of these floods.
Looking north-east from an earthwork platform which
probably served as a livestock refuge.
Overlooking Sawley Cliff Farm, isolated by floodwaters.
Sawley Cliff Farm was abandoned not long after the 1954 floods and the whole area remains prone to periodic flooding. The Lockington marshes have formed the study area for intensive research into river channel formation processes and the relationship between archaeology and dynamic river systems. Does visualisation such as this contribute to such studies? I'm not sure at present, although it may at least open up the area to other, more visually oriented audiences. Of course these visualisations are simply the here and now (well almost), perhaps more interesting would be to recreate the river-scape of 2000 years ago, channel movement, vegetation, environment and settlement, and then explore the impact of the dynamic River Trent on that.
