mples are
LS.
organized,
3. This is
sification
aerial
ographs are
le of the
photography to the mapping scale. One could use a transfer scope but
this could be very time-consuming. Therefore, the interpreted data is
transferred first from the aerial photographs directly to photo mosaics.
This permits the interpreter to see the distribution patterns of
surficial material which develop as the work proceeds. The work is
then transferred to 1:250,000-scale Landsat enlargements by visual
correlation and minor adjustments are made to fit the level of detail
of the interpretation to the finer, smaller map scale. The advantages
of the transfer from airphoto mosaic onto the Landsat enlargements over
the reduction of the airphoto mosaics are as follows:
1. The satellite image is tonally controlled and virtually an ortho-
photo map, whereas the mosaics are photogrammetrically and tonally
uncontrolled.
2. Interpreted features are visually distinguishable on Landsat,
providing better boundary delineation.
3. The Landsat enlargement covers the same area as the topographic
map, whereas eight photo mosaics would have to be combined to
reach this size, entailing considerable edge-fit adjustments.
4. The scale match between the satellite imagery and the topographic
maps permits transfer by overlay.
The author estimates that this method of transfer of data takes one-
tenth of the time it would take to transfer data from the individual
photographs by means of a transfer scope, without the use of satellite
imagery.
This surficial geology mapping program will be completed within
three years and the map sheets published as they are prepared. Each
map sheet will be accompanied by a report describing the surficial
deposits in greater detail and giving illustrations of the interpreted
landforms. It is anticipated that publication will be completed by 1981.
Biophysical Classification of
the Ontario Portion of the
Hudson Bay and James Bay Lowlands
Extending into three Canadian provinces, the Hudson Bay and James
Bay Lowlands are flatlands extending over 250,000 km?, covered with
organic deposits and composed of many types of wetlands (Figure 1).
The program to map the Ontario portion of the Lowlands which will
be described in this section was initiated in May, 1978 (Boissonneau
and Pala, in press). However, the methodology was previously tested
in small wetland reference sites.