forest area, topography. 
On an average it was found that it required some 10 to 12 wor- 
king days to complete a photomap of one mapsheet covering the 
geographical area within 15' latitude and 15' longitude (Approx 
it works out to some 730km?). 
This work was carried out under the supervision of the concerned 
photo-interpreter who was responsible for the showing of the 
various strata boundaries properly on the map. 
1. Showing of reserved and protected forest boundaries 
(RF & PF boundaries) 
The planning for raw material available for forest based indus- 
tries is confined to onlv reserved and protected forests which 
are managed by the Forest Department, Therefore it was necessary 
to show these boundaries on PI map prepared above. The data of 
legal boundaries namely reserved and protected forests was ob- 
tained from the stock maps obtained from the Forest Department. 
These boundaries were then superimposed on the photomaps pre- 
pared above. A list of Reserved and Protected forest blocks was 
prepared mapsheetwise. This helped in ensuring firstly that all 
the legal blocks have been shown on the mapsheet whether full 
or in part as the case may be and secondly whether any minor 
locational adjustments were needed as per the occurance of ve- 
getational growth as seen from the aerial photographs. 
  
About 4 to 5 working days were needed to complete the job of 
showing RF & PF boundaries on one mapsheet which included tra- 
cing and enlargement or reduction as per scale of photomap and 
fitting of forest blocks. 
8. Area calculation 
The last phase of this work was to calculate the area of the 
various strata identified according to the photo-interpretation 
scheme given above. The area calculation for various strata was 
carried out by dot grid method. A oroforma was drawn out which 
gives the break up of the occurance of various strata within a 
forest block. The legally notified area of each forest block 
was taken and the break up of this area into various strata was 
known from the proforma. 
It required on an average some 8 to 10 working days to complete 
the area calculation work of one mapsheet. The time varied ac- 
cording to the scale of photomap. 
9. Conclusion 
Two vital questions of location and extent of forest raw material 
which are one of the basic pre-requisites for industrial planning 
have been well answered with the completion of photomaps as well 
as with the stratumwise area calculation. The experience gained 
has also shown that the small scale of 1:50,000 is good enough 
provided the quality of photographs is excellent to furnish 
the desired results. This way lesser number of photographs are 
to be handled to save both on time as well as money.