An imagery based land information mapping and map udating technique for rural applications
Stringent positional accuracy requirements of traditional land survey departments have tended to hinder the production of land information in order to produce property rights data. Since properly set up land rights databases are required for the effective functioning of the market and for land administration in general, it has become imperative that the rural villages also set up some land management system. This presentation discusses the use of georeferenced/georectified large scale aerial photographs to produce a village plot layout using on screen digitizing and field sketching (to update) that is guided by a printed copy of the aerial photographs overlain with vectors of the current plots. The contention is that the sub-30cm positional accuracy that is required for vector line positions of land parcels and other infrastructure networks is not necessary; the rational is that the attribute data is linked to the plot centroid. In order to prove sufficient accuracy delivered by the this mapping approach, plot layout centroids from the Department of Surveys and Mapping (DSM) plot layout was overlain with the image produced plot layout centroids. The results showed image produced plot centroids positions that corresponded with the DSM plot layout centroids. Adequate accuracy is judged to be one that positions the plot centroids within the correct plot space and around the centre of the plot.
Keywords: Land Information; positional accuracy; imagery guided field based sketching; adequate accuracy; land management system