Air photos are particularly useful to the rural valuer. Rural valuations have the inherent problem of physical access to all parts f the property particularly, for rugged terrain. The access problem is largely overcome with the use of air photos. Air photos are used for initial valuation information and the information is transposed onto the topographical sketch before the inspection of the property.
This provides a good overview of the property before inspection. They are also important during the inspection as they can be taken into the field and post inspection to clarify valuation features not fully inspected.
Air photos are obtainable from the Department of Lands and Government map shops for example, Mapland in South Australia. If the valuer knows the legal description of the property he can identify the property on the Parish, Hundred, County or a specialist Index map.
Air photo runs are shown on the map and the valuer can ascertain the necessary photo numbers. See diagram below:
Most rural areas are covered by black and white photos and a large part of Australia is now covered by colour photos. Colour photos are much better as they allow more reliable identification of rural features such as soil types, crops, health of crops and vegetation. Photos are typically about 230 mm square and for rural regions will have a scale of about 1:40 000 to 1:60 000. Heights flown vary between about 4 500 m to 7 600 m above sea level.
Oblique photos allow a better appreciation of landforms than vertical photos. If available, they can be used in conjunction with verticals and add to the valuation report.
The following are examples of rural and industrial oblique photos:
The following photos show different terrain and topography:
See air photo interpretation