The report assesses the potential for using aerial photography as a tool for supporting field survey – for ultimately assessing tor-grass cover and consequently chalk grassland condition, and understanding the rate of change on Salisbury Plain. Use initial field survey of 20 × 4 hectare plots (200m x 200m) known to contain tor-grass patches/areas. Then, a variety of aerial imagery will be sourced and assessed, to find the best demonstration of tor-grass presence and cover, using the field-mapped polygons as reference. The second aim is to provide Natural England with imagery that best allows visual estimation of tor-grass cover on the Central Impact Area.
The outcome of this project is extremely useful, it assesses tor-grass cover and change on the Central Impact Area of Salisbury Plain. This is required as part of the Integrated Site Assessment of the SSSI. A final report and an enhanced aerial photography layer have been provided, which will be shared with Defence Infrastructure Organisation.
Due to delays in obtaining the different aerial photography layers and CEH being short of time, it was agreed that Natural England would carry out most of the fieldwork – mapping tor-grass areas using Trimble Junos. This was actually very collaborative and productive.