The word geography may be defined in terms of its constituent parts:
geo and graphy. Geo refers to the Earth, and graphy indicates a process of
writing; so geography means writing about the Earth. Very often the „language”
of this „writing” is a map.
An information system
is a chain of operations that takes us from planning the observation and
collection of data through the storage and analysis of data to the use of the
derived information.
Cartographers make
maps. A map is a collection of stored and analyzed data (so a map is a kind of information
systems). Information derived from this collection (to the special kind of
view-point of cartographers) is used making new maps. Earlier only these manual
(or analogue) information systems (topographic and other kinds of maps, aerial
photographs, statistical reports etc.) were used, but nowadays automated
(computer-aided) information systems can be used making new maps as well.
However, we can say that manual GISs play an extremely important role in
constructing such systems, based on digital computers.
Hearing the word GIS,
everybody thinks of a system in a computer containing maps, data and different
kinds of information about the Earth. (In most cases they mean lands only, and
nobody thiks of seas and oceans, although everybody knows that 2/3 of the
Earth's surface is covered by sea water).
Geographical names are those names that we use for the indentification
of natural features or man-made objects on the surface of the Earth (or any
other celestial body).
Gazetteer (by the
Oxford Dictionary): index of geographical names, e. g. at the end of an atlas.
We can continue this definition: gazetteers first of all play important role in
the use of official geographical names and sometimes in the identification of
the places as well where those objects can be found on the Earth's surface
(e.g. using a pair of coordinates for the localization such as the „Gazetteer
of undersea features” does, or using a map enclosed as we can find in the
„Gazetteer of Hungary I”, which includes the major topographic and hydrographic
names). We can say that a gazetteer is a manual database. We also use
geographical names for the identification of different undersea features as
they are natural features of the solid Earth's surface though they are coverred
by sea water.
An undersea feature is
a delimited geographic area with different kinds of associated attributes or
characteristics (first of all its name, its morphological character, vertical
and horizontal dimensions: relative height to its surroundigs, absolute depth
of its highest point from the sea level etc.) Though submarine objects are
delimited areas, in most cases it is not enough for their localization to give
a pair of coordinates.
Undersea features
(spatial objects of the Earth's solid surface) such as other morphological
features on lands can be divided into the following main groups from the point
of view of a GIS (according to Star, J. and J. Estes, 1990): points, lines,
nodes, polygons and chains.
A point is a spatial
object with „no area”. Seamounts or tablemounts, for example are undersea
features, which can be localized by a pair of coordinates.
A line is a spatial
object made of a connected sequence of points. Lines have „no width”. Such
object can be a submarine canyon, a shelf valley or a trench.
Nodes are special
kinds of points usually indicating the junction between lines or the ends of
line segments. (E. g. a connecting point of a shelf valley to a canyon.)
A polygon is a closed
area. Simple polygons are undivided areas, while complex polygons are divided
into areas of different characteristics. The Eurasia Basin in the Arctic Ocean
is a complex polygon, because it is divided into three large parts: the Fram
Basin, the Nansen Cordillera and the Nansen Basin, which are also separately
complex poligons containing different areas of different characteristics such
as subbasins, abyssal plains etc.
Chains are special
kinds of line segments, which correspond to a portion of the bounding edge of a
polygon. (For example a trench can be a part of the „contour line” of a
deep-sea basin.)
It is evident that
lines, polygons and chains cannot be localized by a pair of coordinates.
At Cartographia (the Hungarian Company for Surveying and Mapping) from
the middle of the 80's we studied the relief representation of the sea floor on
different scale maps determining the connection between the scale of maps and
the number and values of isobaths represented. (We called this approach as the
„generalization in vertical sense”.) The results are as follows:
Scale Number
of isobaths
1:25.000.000 and smaller 16
1:25.000.000—1:10.000.000 28
1:10.000.000—1: 7.500.000 31
1: 7.500.000—1 5.000.000 46
1: 5 000.000—1: 2.500.000 68
1: 2.500.000 and larger 111
We role here as an example only the 28 possible contour values for maps
of 1:25.000.000—1:10.000.000. These are: 200, 1000, 2000, 3000, 3500, 3750,
4000, 4200, 4400, 4600, 4800, 5000, 5250, 5500, 5750 and 6000 m.
We derived the rules
of the „generalization in horizontal sense” as well (which gave us how to draw
the lines, which forms have to be emphasized).
On the other hand, we
looked for the method of the construction of correct Hungarian names for
undersea features corresponding to the decisions and recommendations of the U.
N. Conferences on the Standardization on Geographical Names. There is no place
here to summarise the results, and it is not necessary either, because it is
important only for Hungarian cartographers. The only thing we have to mention
here is that it is very useful studying geographical names of undersea features
in different languages for constructing correct Hungarian (or any
other) names, and this leads us to the problems of multilingual
gazetteers. At the end of 1991 we completed the „Multilingual gazetteer of the
Arctic Ocean”. It consists of
four maps and ten chapters as follows:
SEAS
Map 1: Boundaries of
the seas from different sources
Map 2: Boundary of the
Arctic Ocean based on structural-morphological lines
I. The names of the seas
II. Index (Latin)
III. Index (Cyrillic)
IV. The origin of names
UNDERSEA FEATURES
Map 3: Relief map of the
Arctic Ocean
Map 4: Boundaries and
codes of undersea features
V. The names of the
undersea features
VI. Index (Latin)
VII. Index (Cyrillic)
VIII. The origin of names
IX. Generic terms in
geographical names and definitions of undersea features
(in English, French,
German, Czech, Russian, Hungarian)
X. Sources, literature
This gazetteer contains Hungarian, English, German, Czech and Russian
names using the original forms of the names (no transliteration or
transcription). The database is on PC computer. We used DBASE software to store
the names and connecting data (code numbers for the identification of the
objects on the maps, coordinates of the objects, code of sources etc.). Maps
were made by traditional cartographic methods.
We were continuing
this work for the North Atlantic and the North Pacific Oceans with the help of
students at the Eötvös Loránd University, Budapest. These works has been
completed. But in this case the maps also are on PC. We shall create a GIS for
the Oceans using MapInfo software.
As we saw earlier one of the basic material to construct a GIS is a
well chosen map or maps (the map itself is an analogue information system). On
the other hand, we know that map compilation is a chain of operations that
takes us from planning the collection of data, through the storage, analysis
and selection of data, to the use of the derived information for making new
maps (for constructing a new analogue information system).
If we look through the
content of the „Multilingual gazetteer of the Arctic Ocean” we can see that it
is a good database for an information system based, for example, on using
„MapInfo”. It contains all the maps needed for a medium level representation of
the relief of the sea floor; it contains all the maps needed for a high level
representation of the boundaries of the seas and of the main undersea features;
it contains all the needed information for the official English and Hungarian
names and (French), German, Russian and Czech name variants for both the seas
and the undersea features, and we can find in it too, where the names came from
(tell us their origin as well). We think to supplement this completed system
with a new code number which would be useful at the selection of the objects
represented, depending on the scale of the map compiled.
That is why we think
it very important to complete the above mentioned work for the whole World
Ocean. When we finish this work, we shall have a good database for the
compilation of all small scale maps of the oceans and seas from the scale of
1:2.500.000 to the scale of 1:80.000.000; for all kinds of general geographic
maps, world map series, wall maps, atlases and globes.
Márton, M.:
Certain problems of relief representation by contours on small-scale
maps
in: Hungarian Cartographical Studies (Editor: Csáti,E.)
Hungarian National Committee, International Cartographic Association,
Budapest, 1989
Márton, M.:
Tengervízzel fedett felszínek ábrázolása kisméretarányú térképeken
(Kandidátusi értekezés)
(Small-scale representation of the Earth's surface covered by sea water
(Ph.D. thesis)
Budapest, 1991
Star, J. and J. Estes:
Geographic information systems
An introduction
Prentice Hall, New Jersey, 1990