Use of historic aerial photographs to reconstruct the 1946 landscape mosaic of the Eddleston and Ale sub catchments in the Scottish Borders 1
S.Ncube *, C. J .Spray* and A. Geddes* 1
s.ncube@dundee.ac.uk ; *University of Dundee, Scotland, UK
Background The Ecosystem Services Approach (ESA), provides a conceptual framework for the assessment and management of ecosystems and their services (Haines-Young and Potschin, 2010). The UK National Ecosystem Assessment (2011) recommended the need for more case studies on how freshwater catchments can be sustainably managed through the use of an ESA. Habitats play a significant role in the delivery of ecosystem services ( Kandziora et al., 2013), and as such there is need to understand their nature, location, extent and distribution. However, few studies have attempted to look at the ecological history of ecosystems and their services despite the importance of putting the current situation into context in order to help explain ongoing ecosystem changes and patterns (Swetnam et al.,1999). Furthermore, knowledge and information on past Ecosystem Services (ES) can also provide a baseline against which to assess habitat restoration aims and objectives, as well as the potential wider impacts of any proposed measures to achieve them. Set against the above, the aim of this study is to assess and understand the spatial and temporal changes that have occurred to habitats in the Eddleston and Ale sub catchments since the mid Twentieth century, and how these changes have translated in to changes in ecosystem services delivery.
Location of the sub catchments within the Scottish Borders
Stage 1: Developing photo mosaics: use of Photoscan commercial pack-
Stage 2: Visual air photo interpretation and habitat mapping (Backdating approach in ArcGIS) Attributes retained
New 1946 column
2. Change habitat map symbology
1. Overlay datasets
Ancillary dataset layers
4. Interpret and assign 1946 habitat class with aid of ancillary datasets
5. Edit (i.e. merge or clip &label) habitat boundaries to match the assigned 1946 habitat class
3. Start editor and zoom to interpretation scale 1: 4000
6. The output from this process is the reconstructed 1946 habitat map
Methodological framework 1:10 000 Royal Air Force 1940s aerial photographs were used to reconstruct the landscape mosaics. Data layers used:
Use of Photoscan to produce historic (1946) orthophotos for these sub catchments
Gather historic photos for the Ale and Eddleston sub catchments
2
1
Historic orthophotos from stage 1 Current aerial photographs Current habitat layer DTM (hillshade) Soil data layer Hedge rows data layer OS maps
Use of ArcGIS to visually interpret, edit/digitise/map and relabel the current habitat vector layer; backdating it to 1946.
Produce historic habitat/ land cover layers for the Ale and Eddleston subcatchments.
3
Stage 3: Ecosystem services mapping: Use of expert rule base approach Spatial Evidence for Natural Capital Evaluation (SENCE) method
4 2009
Use of algorithms and rule base
Stage 1
Flood control – ES stock maps
1946
Stage 2 Historic Ecosystem Services Mapping Factors influencing ecosystem services delivery: Habitat/LC type and condition Underlying geology and soil type Position in the landscape e.g. on a steep slope Management e.g. statutory designation (Environment Systems Ltd)
Eddleston Village
5 Current habitat and ecosystem services mapping of the Scottish Borders by Env Systems to be used as a reference point
Stage 3 Habitat and ecosystem services change analysis (using historic habitat and ecosystem services layers from step 4 and 5)
6 Peebles
Next steps: Analysis of the major changes in habitats and ES between these two dates and the implications of these changes.