BGS undertook an aerial survey of the Trent Valley flooding event on 9 November 2000. These photographs were used to establish a link between flooding and Geology.
This case study was the initiator for the creation of the Geological Indicators of Flooding dataset (GIF). The case study established that in detail, geological maps show that the floodplain corresponds to the extent of Alluvium, which represents the clay, silt, sand and gravel deposits laid down by fluvial activity (meander migration and flooding) related to the modern river channel (see LiDAR image). Many larger floodplains include additional areas of raised ground representing the 'first terrace' or the 'floodplain terrace', which is overlapped by the alluvium (see geological map).