River Teme aerial survey and habitat walkover (2017)
Client: Severn Rivers Trust / Environment Agency
BUG was commissioned by Severn Rivers Trust and the Environment Agency to conduct an aerial survey and habitat walkover survey to provide a baseline characterisation of fish habitat in advance of the partial removal of Powick Weir, with a view to conducting a repeat survey post-weir removal to quantify changes to the river upstream.
The surveys were undertaken as part of the ‘Unlocking the Severn for Life Project’, which is funded by the EU LIFE Nature Programme (LIFE15-NAT-UK-000219) and the Heritage Lottery Fund (HLF15-04573), with delivery partners including Severn Rivers Trust, Canal and Rivers Trust, Natural England and the Environment Agency.
An aerial survey was undertaken using a Small Unmanned Aircraft System (SUAS), or drone, to collect high resolution imagery from an altitude of 50 m, providing a ground resolution of 2.1 cm/pixel. The survey encompassed a 4 km stretch of the River Teme, from just downstream of Powick Weir to Bransford Bridge.
A total of more than 2,100 images were taken and stitched together into a high resolution geo-referenced orthomosaic, using Ground Control Points recorded during the habitat walkover survey. The outputs of the aerial survey were presented in GIS format, with the results of the habitat walkover survey overlaid as a mosaic of habitat and flow categories.
Using a combination of drone aerial imagery and habitat walkover data has provided a cost-effective way of collecting a solid baseline of existing riverine habitat, against which any changes post-weir removal can be compared. In addition, the aerial imagery provides an invaluable and easily accessible format of baseline information for inclusion in the public consultation process and stakeholder engagement.