at this scale and even at the scale of 1:25,000, must be 
cartographically enhanced, in order to be readable. This 
process defeats to a certain degree one of the major advantages 
of the ortho photo map process. 
In areas of shifting cultivation the ortho photo 
map would be at a considerable disadvantage, since it depicts e e 
the cultivation pattern as of the date of photography. The 
cultivation patterns can change completely within a year, and 
a one year old photo map would be confusing to the user as it 
would bear no resemblance to the ground, other than permanent 
features such as drainage. In these cases, a line drawn map 
is superior to an ortho photo map. It should also be considered 
that good quality reproduction of photo maps is more difficult 
and costly than reproduction of a single colour, or two colour e 9 
line drawn map. A line drawn map at a scale of 1:50,000 is 
preferable to a photo map at the same scale. However, ortho 
photo maps at larger scales such as 1:2,000 or 1:5,000 merit 
careful consideration, particularly if they are to be used for 
special purposes such as road locations, pipeline locations, 
irrigation, etc. 
AERIAL PHOTOGRAPHY 
  
The scale of the aerial photography, the type of 
emulsion and the choice of either wide or super-wide angle