Figure 2. Guyana: Topography and Drainage
With a land area of approximately 197,000 square kilometers,
Guyana is about the size of Idaho. The country is situated between
1 and 9 north latitude and between 56 and 62 west longitude.
With a 430-kilometer Atlantic coastline on the northeast, Guyana is
bounded by Venezuela on the west, Brazil on the west and south, and
Suriname on the east. The land comprises three main geographical
zones: the coastal plain, the white sand belt, and the interior
The coastal plain, which occupies about 5 percent of the
country's area, is home to more than 90 percent of its inhabitants.
The plain ranges from five to six kilometers wide and extends from
the Courantyne River in the east to the Venezuelan border in the
The coastal plain is made up largely of alluvial mud swept out
to sea by the Amazon River, carried north by ocean currents, and
deposited on the Guyanese shores. A rich clay of great fertility,
this mud overlays the white sands and clays formed from the erosion
of the interior bedrock and carried seaward by the rivers of
Guyana. Because much of the coastal plain floods at high tide,
efforts to dam and drain this area have gone on since the 1700s
(see The Coming of the Europeans
, ch. 1).
Guyana has no well-defined shoreline or sandy beaches.
Approaching the ocean, the land gradually loses elevation until it
includes many areas of marsh and swamp. Seaward from the vegetation
line is a region of mud flats, shallow brown water, and sandbars.
Off New Amsterdam, these mud flats extend almost twenty-five
kilometers. The sandbars and shallow water are a major impediment
to shipping, and incoming vessels must partially unload their
cargoes offshore in order to reach the docks at Georgetown and New
A line of swamps forms a barrier between the white sandy hills
of the interior and the coastal plain. These swamps, formed when
water was prevented from flowing onto coastal croplands by a series
of dams, serve as reservoirs during periods of drought.
The white sand belt lies south of the coastal zone. This area
is 150 to 250 kilometers wide and consists of low sandy hills
interspersed with rocky outcroppings. The white sands support a
dense hardwood forest. These sands cannot support crops, and if the
trees are removed erosion is rapid and severe. Most of Guyana's
reserves of bauxite, gold, and diamonds are found in this region.
The largest of Guyana's three geographical regions is the
interior highlands, a series of plateaus, flat-topped mountains,
and savannahs that extend from the white sand belt to the country's
southern borders. The Pakaraima Mountains dominate the western part
of the interior highlands. In this region are found some of the
oldest sedimentary rocks in the Western Hemisphere. Mount Roraima,
on the Venezuelan border, is part of the Pakaraima range and, at
2,762 meters, is Guyana's tallest peak. Farther south lies the
Kaieteur Plateau, a broad, rocky area about 600 meters in
elevation; the 1,000-meter high Kanuku Mountains; and the low
Acarai Mountains situated on the southern border with Brazil.
Much of the interior highlands consist of grassland. The
largest expanse of grassland, the Rupununi Savannah, covers about
15,000 square kilometers in southern Guyana. This savannah also
extends far into Venezuela and Brazil. The part in Guyana is split
into northern and southern regions by the Kanuku Mountains. The
sparse grasses of the savannah in general support only grazing,
although Amerindian groups cultivate a few areas along the Rupununi
River and in the foothills of the Kanuku Mountains.
Data as of January 1992