Photogrammetry and Geodetic Surveying in the 
Planning of Hydroelectric Power Stations 
By Einar Rehnlund, VIAK, Stockholm 
Introduction 
Of recent years the State Power Board of Sweden has made exten- 
sive use of photogrammetric and geodetic procedures in the prepara- 
tion of plans for the development of the water power resources in the 
north of this country. Modern surveying methods have made possible 
the rapid collection of information for reconnaissance of large areas 
in à short time. 
Aerial photographs have come into widespread use for a great variety 
of applications in the work of the State Power Board. During the past 
year, the Power Board ordered more than 10.000 paper prints and dia- 
positives from the Geographical Survey Office. These photographs 
were used for plotting maps; for levelling and contouring; for scaled- 
down studies of contemplated projects; and for recording traverses, 
exploratory boreholes, seismic profiles, geologic notes, and the like. 
The table below shows the areas plotted to various scales during 1959 
for the Planning Department and the Flow Regulation Department of 
the Power Board. 
Scale Hectares Plotted 
1:40.000 250.000 
1:10.000 445.000 
1:4.000 37.000 
1:2.000 9.800 
During the same period, the number of models photogrammetrically 
triangulated was 965. 
The applications of geodetic surveying have developed apace with 
Sev JS 
those of photogrammetry in the work of the Power Board. Modern 
geodetic procedure was introduced in order to make possible the estab- 
lishment of ground control points as rapidly as required. The Power 
Board, for instance, was the first organization in this country to apply 
the geodimeter and the tellurometer, two electronic instruments for 
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