TWO METHODS OF DETAILED GEOMORPHOLOGICAL MAPPING
(WITH COLOURED EXAMPLE)
by
H. J. VAN DORSSER and A. E SALOME
In addition to the "Different methods of de-
tailed geomorphological mapping" (Van Dors-
ser Salome, 1973)1 two new Systems have
been tested in the same small area of the
southern most part of the Netherlands.
The methods used
a) Method of the unified key to the detailed
geomorphological map of the world2. This
system has been published in 1968 by the
I.G.U. Subcommission on Geomorphological
Mapping. At that time no maps, made accord-
ing to this system, were published. The first
maps published, that came to our attention,
were the ones published in 1972 (Demek).
The base map is a simplified topographic map
with contour lines in grey and hydrography in
blue. Man made forms are indicated in black.
In this system the other colours are used for
genetic groups of landforms. Symbols for the
individual forms are used in füll colours. It is
suggested to use the füll colour for recent
forms and shades of colour for the older ones
in the legend. It is also possible to indicate the
ages of the landforms by letter symbols, this
method is more convenient and is used in our
map. The slopes have been grouped in six
categories.
Shading in grey should be used over the colours
of the genetic landforms for the slopes from
0-2°, 2-5°, 5-15°, 15-35°, 35-55° slopes over
55° should be marked by a cliff signature in
the appropriate colour. From the colour shades
added to the legend of 1968 it was already
obvious that it was difficult to distinguish two
and sometimes even three successive shades
from one another. In the maps of 1972 this
difficulty became even more clear. Probably
to save on the costs of printing the slope
categories have not been indicated by a super-
imposition of grey shades over the colours,
but by shades of each colour itself. In our
map we used the same method. Since in our
area slopes of over 19° did not occur, only
three classes have been distinguished. In doing
so the three shades of the colours in our map
can easily be discerned from one another.
Technically it would have been very difficult
to make a distinction between more shades
of the same colours.
This map clearly shows resemblances with the
ones of the Czechoslovak and the Polish Aca-
demies of Sciences.
b) Method of the detailed geomorphological
map of France. This system of the "Com-
mission de cartographie geomorphologique"
has been introduced by Tricart (1972 a) to be
used for the "Carte geomorphologique detaillee
de la France" in the scales 1 20.000, 1 25.000,
and 1 50.000. The system also replaces the
method of the Centre of Applied Geography,
Strasbourg as described in our 1973 publica-
tion.
The base map is a simplified topographic map
with contour lines in brown and hydrography
in blue. Anthropogeneous forms were indicated
in the old system. In the new one no signatures
for anthropogeneous forms are given, they are,
however, mentioned in the accompanying text.
Therefore, in the map the hollow roads are
indicated in black. For the geological structure
and lithology symbols are used in the colours
red-orange-brown. Yellow is used for eolian
deposits. The other colours have been reserved
for indicating the morphogenesis according to
the processes acting under the different climatic
conditions. In this use of colours lies the main
change in the new system as compared with
the former system propagated by Tricart. With
the use of colour shades it is possible to
indicate the age of the landforms. Loess should
be indicated in the colour used for periglacial
467
K.N.A.G. Geograßsch Tijdschrift VI II (1974) Nr. 5
