the use of other colours in the geomorphological
map accompanying the text (Verstappen
Van Zuidam, 1968), as is advised on p. 7 of
that same text, is inadmissibleas also is the
difference in size of symbols in legend and map.
5. Method of the Centre of Applied Geography,
Strasbourg (Tricart, 1965). This method is
designed as a universal System. The base map
is a simplified topographic map with contour
lines in brown and hydrography in blue (Tricart,
1965, p. 187). The geological structure is indicat-
ed by coloured symbols. The lithology is marked
on the map where superficial deposits are less
than 1 m in thickness. The geomorphological
forms are marked by symbols, their ages being
indicated by colours. A distinction is made
between erosive and accumulative forms. A num-
ber of processes are also indicated. Tricart
and his co-workers use their System rather
freely and adaptations for regional differences
are possible. Unforgivable, however, is the use
of blue for contour lines and black for hydrolo-
gical features in the map illustrating the System
(See Annexe 1 of the book by Tricart, 1965).
The geomorphology of Noorbeek and sur-
To compare the merits of the live Systems a
small area near Noorbeek, in the extreme
southern part of the Netherlands, was mapped.
This area is depicted on the topographical map
of the Netherlands 1:25,000, sheet 62 C,St
Geertruid, edition 1968. A reproduction of the
grey tone edition with contour lines in brown
is given with this article. A simplified Version
of this map is used as a base for the different
geomorphological maps. In all cases the base
has been printed in grey and the contour lines
in grey or brown according to the System
being used.
The data used in the maps were obtained from
publications by Zonneveld (1955) and Van den
Broek Van der Waals (1967), by the Inter
pretation of aerial photographs and from a
short fieldwork.
The area consists of a dissected peneplain of
Pliocene age and of a partly dissected terrace
of the river Meusethe so-called 'Terras van
Noorbeek'. This terrace has not been precisely
dated but is most probably of the Early Pleisto-
cene (Zonneveld 1971, personal communication).
The whole area has been covered by loess of
Weichselian age.
On that part of the topographic map given here,
several geomorphological units can easily be
seen: the flat remnants of the terrace in the
north, the steep northern valley-side of the river
Noor, the remnant of the peneplain in the south
and the dry Valleys which dissect the southern
part of the area.
1. Map according to the method of Annaheim
and Moser. This map, with only the two colours
red and green, gives a clear picture of the land-
forms of the area. The symbols indicating the
loess cover have been superimposed on the area
symbol indicating the river terrace. This is
probably not according to the original legend,
but it proved to be very practical. The lighter
tone of green used for the river terrace indicates
a difference in age between the terrace and the
loess cover.
2. Map according to the method of the Czecho-
slovak Academy of Sciences (Demek). In the
legend used by Demek no reference is made to
the thickness of the loess drift.3 Since the major
part of the area is covered by loess, the older
forms are masked when only this loess cover
is mapped. Therefore, we decided to make
two maps, one indicating the superficial forms
only and the other indicating also the land-
forms covered by the loess. In the adapted
version a stripe pattern is used, following the
way in which Tricart combines two different
symbols.
In the first map the geomorphological units
visible in the field cannot be seen. Only by
the difference in colour used in the symbol
of the dells, is an indication given of the age
of the substratum. In our opinion the second
map gives a better picture of the geomorphology
of the area.
The use of colours for the chronology as well
as for the geomorphological units presents
difficulties.
In printing, the loess symbol posed a technical
Problem. According to the legend a point screen
(composed of three colours) should be used.
The colour used in this map is the one used for
steep loess drifts in the original legend. This
legend distinguishes between steep, gentle and
flat slopes of loess drifts without defining these
classes. In the map illustrating Demek's legend,
the colour tone used for steep slopes of loess
drifts is incorrectly used for gentle slopes (about
2 1/2 percent).
ROUNDINGS
COMPARISON BETWEEN THE DIFFERENT GF.O-
MORPHOLOGICAL MAPS 2
72
K.N.A.G. Geografisch Tijdschrift VII (1973) ATr. I
