Topographic mapping in Venezuela is the responsibility of
the Servicio Autónoma de Geografia y Cartografía
Nacional (SAGECAN) (formerly the Dirección de Cartografía
Nacional) within the Ministerio del Ambiente y de
los Recursos Naturales Renovables (MARNR). The organization
was founded in 1935 and photogrammetric survey
of the country began in 1938. A basic mapping scale of
1:25,000 was selected, with contours surveyed at 20 m intervals.
More than 5,000 sheets have been produced in this
series. Cover does not yet extend to the far south or east
of the country, and in a few areas a basic scale of 1:50,000
has been preferred.
In 1946, technical assistance from the Inter-American
Geodetic Survey was negotiated, and map series at scales of
1:100,000 and 1:250,000 were also started at about this
time. The 1:100,000 scale series is currently perhaps the
most useful of all the topographic series, covering about
three-fifths of the country. A new version was started in 1962
to replace the preliminary edition, and sheets have a 30'
longitude by 20' latitude format. This is a good quality,
five-color map with 40 m contours.
The 1:250,000 scale series was re-cast in its present form
on IMW sheet lines in 1970, and published sheets cover all
of the north and much of the south of the country, in the
latter area partly as 'picto-radar' maps. The series is in seven
colors with contours at 50 m or 80 m intervals. A complete
cover of the country at the scale of 1:250,000 is also available
as semi-controlled radar mosaics. There is also a
complete cover of maps at 1:500,000 scale, though in the
south, these are described as copias heliograficas.SAGECAN
has also published a number of large-scale maps of cities,
and a complete set of general purpose maps of each state or
federal territory (Entidades federales) with varying scales.
The more recent topographic sheets are based on the UTM
projection, except for the 1:500,000 scale series which is on
a Lambert conformal conical projection. The ellipsoid is
Hayford International. Older series mapping (before 1962)
was on a secant conical projection.
Quality of topographic mapping has began to improve as a result of several
collaborative projects between SAGECAN and the Institut
Cartogràfic Catalunya (ICC), Spain. These include the
production of a new 1:250,000 scale digitally-produced
coverage of the country in 84 sheets and a set of 93 1:25,000
scale orthophotomaps of Caracas and the surrounding area
produced from color air photography. A major project to
help in the restructuring of the Venezuelan agricultural
sector was began in 1997. This will result in production of
1,500 topographic map sheets at 1:25,000 scale covering
states north of the Orinoco. This work has been commissioned
by the Ministerio de Agricultura y Cría. The maps are being prepared from orthoimages
created from new panchromatic air photo cover, and
georeferencing is being carried out using the GPS. The states
of Amazonas and Bolivar, south of the Orinoco are to be
covered by digital radar orthoimages at 1:50,000 scale in a
contract with SAGECAN.
Soviet military topographic mapping of Venezuela is available at the following scales: 1:1,000,000 (11 sheets, complete coverage, published 1966-1990);
1:500,000 (27 sheets, complete coverage, published 1964-1988) and city (1:10,000) topographic maps of Caracas and Maracaibo published between 1979 and 1981.
These products are available in print, digital raster and digital vector GIS formats from East View Geospatial.
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