INDIA 7 
In Survey of India maps are prepared for a great variety of purposes. Apart from the depart 
mental topographical maps on 1 : 50,000 scale with contour intervals ranging from 20 metres for 
undulating areas to 40 metres for steep areas which is the normal departmental commitment, maps 
are prepared for reservoir and dam site surveys of hydro-electric and irrigation schemes, large scale 
development plans, medium scale maps for exploration of mineral resources, siting plans for refineries, 
town planning surveys, guide maps and excavation plans of archaeological ruins. Table 5 gives the 
total map coverage produced by the Survey of India and Messrs. Air Survey Company Private Ltd., 
by photogrammetric method during 1960-64. During the same period, an area of 1,75,626 sq. km 
was surveyed from aerial photographs by Arundel method on scales ranging from 4" = 1 mile to 
1:50,000. 
Table 5.—Photogrammetric Survey in India during 1960-64 
Serial 
No. 
Type of map 
Scale of 
map 
Scale of 
photograph 
Area in 
sq. km 
Remarks 
A. Survey of India 
1 
Departmental Topo Maps 
1 : 50,000 
1 : 60,000 
83,507 
1 : 32,000 & 
9,081 
. 
60,000 
1 : 50,000 
32,858 
1 : 40,000 
20,166 
1 : 30,000 & 
13,310 
50,000 
1 : 25,000 
1 : 60,000 
80 
2 
Irrigation Maps 
4" = 1 mile 
2" = 1 mile 
1,632 
3 
Mineral Resources Maps 
1 : 1,000 
1 : 10,000 
1-77 
1 : 2,000 
1 : 10,000 
3-14 
1 : 10,000 
1 : 10,000 
108 
1 : 2,500 
4" = 1 mile 
14 
1 : 25,000 
1 : 40,000 
141 
1 : 50,000 
1 : 50,000 
2,833 
4 
Development Plans 
1 : 10,000 
1 : 40,000 
233 
5 
Town Planning Maps 
1 : 8,000 
1 : 30,000 
81 
1 : 10,000 
4" = 1 mile 
845 
1 : 15,000 
1 : 40,000 
18 
1 : 20,000 
2" = 1 mile 
1360 
6 
Development Project Maps 
1 : 5,000 
10" = 1 mile 
9-73 
1 : 25,000 
1 : 50,000 
495 
7 
Archaeological Maps 
1 : 8,000 
1 : 15,840 
31 
B. M/s. Air Survey Company 
8 
Development Project Maps 
25" = 1 mile 
36-25 
16" = 1 mile 
67-59 
8" = 1 mile 
18-11 
6" = 1 mile 
699-26 
2 • 5" = 1 mile 
647•46 
l : 4,000 
56-98 
1 : 5,000 
64-72