Archaeological prospecting in woodland using LiDAR - summary of 2009 surveys

Light Detection And Ranging (LiDAR) surveys are one of our Woodland Heritage Services

Ironbridge Gorge World Heritage Site

The wooded slopes and hills surrounding the gorge, combined with the areas world famous industrial heritage made Ironbridge an obvious location for the potential benefits of LiDAR, with its ability to map the landscape beneath the canopy. Results from the survey did not disappoint, with wooded areas revealing many sites of former industrial activity, including bell pits, quarries, building remains and charcoal hearths. However, in some wooded areas, the effectiveness of the survey was reduced due to the high abundance of holly which led to many gaps in the terrain model. Surprisingly perhaps, is the fact that this lack of a good terrain model in many places is being used to help to target areas where some active holly control would be desirable. Outside of wooded areas, the survey produced a 3-Dimensional map with sufficient detail to show former agricultural processes in some fields, the rails of an inclined plane and even the railings of the iron bridge itself.

  • LiDAR modelled ground surface image of quarried ridge and charcoal hearths on facing slope at the Ironbridge Gorge World Heritage Site
    Quarried ridge and charcoal hearths on facing slope
  • LiDAR modelled ground surface image of Abbey ruins at the Ironbridge Gorge World Heritage Site
    Abbey ruins
  • LiDAR point cloud image of the Iron Bridge
    Point cloud image
    of the Iron Bridge

The New Forest (part of)

A survey of a section of the New Forest was undertaken during the winter of 2009, incorporating areas of both woodland and open heathland. The survey showed many features on the heathland already known from traditional aerial photographic mapping and other historic records. Open heathland features identified include burial mounds, mineral extraction, boundary earthworks and search light batteries. Under the woodland, the survey showed many earthworks, relating to a variety of monuments, boundaries and extensive drainage systems. The variety of drainage patterns evident are intriguing, perhaps indicating either different periods or practical approaches. Finally, the New Forest also has many veteran trees and many of these are distinguishable in the LiADR data.

  • Aerial photo of New Forest woodland canopy
    Aerial photo of forest canopy
    LiDAR modelled ground surface of New Forest woodland
  • LiDAR modelled ground surface
  • Aerial photo of New Forest woodland canopy
    Aerial photo of forest canopy
    LiDAR modelled ground surface of New Forest woodlands
  • LiDAR modelled ground surface
LiDAR mage showing the location of some taller, perhaps significant trees in the New Forest
Location of some taller, perhaps significant trees
Enlarge (image size 146K)

The Weald Forest Ridge (south and east)

The Weald Forest Ridge has Ashdown Forest at its heart, but incorporates a belt of land extending east-west from Horsham in West Sussex, to Royal Tonbridge Wells in Kent. As with so many landscapes with abundant woodland cover, the county based Historic Environment Records showed fewer entries for the wooded areas when compared to the more open environments. Once again the application of LiDAR is helping to readdress the balance. To date, only half of the Weald Forest Ridge has been captured, with the remaining area due to be completed during the early months of 2010. Nonetheless, data acquired to date is already proving informative, mapping many new features of archaeological interest in addition to those already known. Like many parts of the Weald, quarries, route ways and water management systems associated with the areas iron industry are evident. Pillow mounds (artificial rabbit warrens) are also visible, both in currently open and wooded landscapes. Investigations into the findings of the first half of the survey are ongoing.

  • Aerial photo of Weald Forest Ridge wooodland canopy
    Show aerial photo of forest canopy
    LiDAR modelled ground surface of Weald Forest Ridge
  • Show LiDAR modelled ground surface
  • Aerial photo of Weald Forest Ridge wooodland canopy
    Show aerial photo of forest canopy
    LiDAR modelled ground surface of Weald Forest Ridge
  • Show LiDAR modelled ground surface