A Mine Entry with Potential Zone of Influence is the area of the ground that might be affected if subsidence of the mine entry was to occur. Each mine entry has a zone of influence buffer around the mine entry calculated from the same algorithm used in producing a ‘Mine Entry Interpretive Report’. The Zone of Influence (ZOI) highlights the area on the surface that could potentially be affected in the unlikely event a collapse was to occur. The calculation takes into account the size of the mine entry entrance, the geological ‘drift’ deposits for the area and the original source from which the mine entry was captured.
The layer shows a mathematical area, which may be affected and does not attempt to take into account the varying local geological conditions that may affect this. Where the calculated ZOI is less than 20m then a default value of 20m is used.