Flow diagram 2
A
Q
Existing
topographic
maps
Interpretation of
small scale aerial
photography
i
Construction of
medium scale
orthophotomap
with contours
or a photo-
mosaic
Photo delineation
and plotting
Planning the best route
1.
2.
5.
.
3.
2.
5.
l.
Ze
Delineation of l.
potential areas e.
for road passage, 5.
comparison of all Le
possible routes, 5.
selection of the 6.
best traverse 7.
i
Acquisition of l.
large scale aerial
photography cover- 24
ing the area of the
proposed route 5.
4,
Protting of the route/ 1.
to the orthophotomap | 2.
Intensive field- l.
check and office 2.
work %
5.
4,
Delineate the region to be opened up
Mark the cardinal points on the map
Study the landforms
Design a plan for small scale aerial
photography
landforms, drainage system,
ruggedness of the terrain
Topography -
Soils - physiography, soil type and
bearing capacity, deposits
of gravel, sand, etc.
Land cover - land use, property boundaries
Forests - area under forest cover,
tree species composition,
stand age and stocking
Cardinal passages: start and terminal,
bridges, mountain passes, cutting sites,
loading sites, sawmill, fire lookout,
camp site, scenic areas.
Areas with restricted passage:
swamps and areas subject to flooding,
unstable soil and landslides,
protected areas (nature reserves etc.)
obstacles (powerlines, rockoutcrops,
houses, etc.)
Plotting of the routes on the contourmap
Construction of the approxümate profiles
Discussion on critical passages
Estimation of construction costs
Discussion on economical aspects
Selection of the best route
Field reconnaissance of selected route
Delineation of the cardinal points and
the restricted areas.
Photo interpretation on the topography,
measurements of the slopes.
Rough location of the traverse
Road layout on the photographs
Construction of the road profile
Study of the cross sections along the
traverse,
Location of the traverse in the terrain
Check on gradient and cross sections,
bridge locations, obstacles, etc.
Tests on soil bearing capacity (field and lab.)
Determination of cuts and fills