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This data was created by means of visual interpretation and vectorization of SPOT 5 imagery (panchromatic sharpened images (2.5 m resolution) merged with multispectral bands (10 m resolution) to produce a 5 m resolution images) from various acquisition dates in 2006 to 2008. The outer boundary of gullies were delineated from SPOT 5 satellite images in ArcMap. Gullies were identified by their tone, shape, drainage pattern and association. Furthermore, compression of imagery (i.e. to enhanced compressed wavelets) made it possible to rapidly and simultaneously view several images as one layer in a seamless coverage (i.e. using Image Catalogue developed as an extension in Esri® ArcMap software). In order to ensure that the full extent of the Province is roamed at a scale of 1:10 000, an annotation layer in the form of a series of vertical and horizontal lines was created using Hawth's Analysis Tools (developed as an ArcGIS 9.3 extension). |