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Spatial information technologies to aid Archaeological Site Mapping Image Classification Supervised classification approach was applied to delineate roads network employing ERDAS IMAGINE software to generate land use of the study area using a maximum likelihood classifier (MLC) technique. The prime concern is to map out roads, then generated land use classes are merged until two classes were produced namely as roads, and non-roads (background) which comprised classes that do not have any association with roads. This map is used in the process of road location. Data Editing and Field Verification As the roads coverage provided by DELM was based on 1989 map compilation, some parts of the VDL roads network exists in the topography map. Some parts of the VDL network did not show up those data since much of the knowledge of the location of the early alignment has been lost or overwritten as there has been little later permanent settlement in the area. Fig. 6 also provides missing VDL road segments which are presented in red colour, and the road segments that did not appear on the available digital data were digitised and edited into the VDL road coverage. This information has been compiled from field verification, local knowledge, and ancillary maps in order to reconstruct and update the VDL network. Ancillary data and maps include topographic map sheets of Lea (4239), Pencil Pine (4039), Liena (4040), County Chart (Lincoln 1), Forestry Commission Forest Type (Daisy Dell), Archives of Tasmania VDL Co maps and Sorell Survey maps 1877 used to extract DVL segments and were input onto a GIS. The County Chart and Forestry Commission Forest Type were useful in identifying some sections of the route. But the older maps did not provide significant data other than giving an historical perspective. Screen and tablet digitising from geocoded imagery and the topographic map respectively using ARC/INFO software generated the roads and tracks of the study area. Then maps were joined by an edge-matching technique. Field data collection has been undertaken by an archaeologist, a GIS operator, and foresters using a number of maps to verify local knowledge about the existence of VDL roads network. In addition, GPS (GPS Explorer) were used to verify both local knowledge, and the information from the maps. It was difficult to locate and identify some parts of VDL network. Much of the knowledge of the location of the early alignment has been lost or over-written, as there has been little later permanent settlement in the area. In addition, timber harvesting activities and logging practices in the 20th century may have reused the road or have snigged over the alignment altering its structure. For example, in the Liena area it was found that there are many tracks that either run parallel to each other or intersect one another. Even local knowledge could not assist in identification of which of these was the actual VDL segment. Thus, the only solution was to specify an approximate track (line) to represent the VDL route (Fig. 7).   Fig. 6: Shows road networks red and yellow were overlaid onto the georeferenced image. The yellow lines are the existing roads on the topographic map. The red lines are the compiled VDL road networks. Remarks Utilised GIS/RS integrated approach provided a scientifically justifiable and generally applicable approach to variable historic site identification, recording, and mapping. The output can be potentially integrated into a planning framework to support resource and environmental planning, management, and decision making. Despite the fact that this report has been able to provide the best possible estimate of the location of the road, we recommend that further ground truthing will be required to verify this conclusion.  Fig. 7: Diagrammatic representation of the reconstructed of the VDL route. References
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