Pre PRL Clearing

The Pre-PRL Clearing dataset shows the extent of major land clearing before Phosphate Resources Limited (PRL) began mining on the island in the early 1990’s. It was provided to Geoscience Australia in early 2011 by PRL. This shapefile is a first pass only. There is the possibility of adding further cleared areas through closer inspection of the orthophoto’s and redefining some of the edges to more closely represent the area cleared. The Pre-PRL Clearing data was digitized by hand by PRL in October 2010 from aerial photographs taken in 1976, 1982 and 1987. The 1976 image was used first, then 1982, then 1987 making sure that each polygon snapped to the last. Generally digitises at 1:5000 although this is variable. All polygons have been assigned an attribute and the year represent the first time the area is indicated as being cleared off the orthophoto. This data is logical as each attributed year shows the progress of clearing across Christmas Island in a logical manner. [Disclaimer]( https://www.infrastructure.gov.au/utilities/disclaimer.aspx)