the orthophoto was first made from many vertical aerial photograph that partly covered one another. this was done to create scale correct images.
orthophoto maps are created by adding map information to the orthophotos
an orthophoto map is the combination of map and a photograph.
it has a large scale (1:10,000) than the topographical map, so features appear larger.
it is more representative of the reality than the topgraphical map
orthophoto maps can have contour lines superimposed on them to provide a sense of the relief of the landscape. in this way they can provide critical information about where to build or to assess areas most at risk during flooding
advantages of orthophoto maps
- orthophoto maps have large scale of 1:10000 so features can be seen quite easily
- othophoto mapping is quick and easy to use for updating maps
- most urban areas and major growth point are covered
disadvantages of orthophoto maps
- orthophoto mapping is not yet available for the whole of Africa
- new full colour orthophoto image has been made available to the general public only recently so are difficult to get