Geography of Dominica

From Wikipedia, the free encyclopedia

Dominica is an island in the Caribbean Sea, located about halfway between Puerto Rico and Trinidad and Tobago. Its coordinates are 15 25 N, 61 20 W. The island is roughly four times the size of Washington, DC (in area, not population).

The island's climate is tropical, moderated by northeast trade winds and heavy rainfall. The interior features rugged mountains of volcanic origin. Volcanism is still quite evident on the island, the most popular examples being Dominica's boiling lake and "valley of desolation." The boiling lake (the world's second largest) is within a crater and is fed by a waterfall - the boiling is believed to be caused by the heat of a magma chamber beneath the lake. The valley of desolation is a sulfurous valley of volcanic vents and hot springs that inhibits significant plant growth - in stark contrast to the surrounding rain forest. The lowest point in the country is at sea level along the coast, and the highest is Morne Diablotins (1,447 m). The extreme southwestern coast of the island includes a large collapsed submarine caldera. Portions of the exposed rim of this caldera form the southwestern tip of the island at Scott's Head.

Natural resources include farming, hydropower and timber.

Geographically, Dominica is distinctive in many ways. The country has one of the most rugged landscapes in the Caribbean, covered by a largely unexploited, multi-layered rain forest. It is also among the earth's most rain-drenched lands, and the water runoff forms cascading rivers and natural pools. The island, home to rare species of wildlife, is considered by many as a beautiful, unspoiled tropical preserve. According to a popular West Indian belief, Dominica is the only New World territory that Columbus would still recognize.

Dominica is the largest and most northerly of the Windward Islands. The island faces the Atlantic Ocean to the east and the Caribbean Sea to the west. Its nearest neighbors are the French islands of Guadeloupe, some forty-eight kilometers north, and Martinique, about forty kilometers south. Oblong-shaped and slightly smaller than New York City, Dominica is 750 square kilometers in area, 47 kilometers in length, and 29 kilometers in width. Roseau, the nation's capital and major port, is favorably situated on the sheltered, southwestern coast.

Geologically, Dominica is part of the rugged Lesser Antilles volcanic arc. The country's central spine, a northwest-southeast axis of steep volcanic slopes and deep gorges, generally varies in elevation from 300 meters to 1,400 meters above sea level. Several east-west trending mountain spurs extend to the narrow coastal plain, which is studded with sea cliffs and has level stretches no wider than 2,000 meters. The highest peak is Morne Diablotins, at 1,447 meters; Morne Trois Pitons, with an elevation of 1,423 meters, lies farther south and is the site of the national park.

Dominica's rugged surface is marked by its volcanic past. Rock formations are mainly volcanic andesite and rhyolite, with fallen boulders and sharp-edged protrusions peppering slope bases. The light- to dark-hued clayey and sandy soils, derived from the rocks and decomposed vegetation, are generally fertile and porous. Only a few interior valleys and coastal strips are flat enough for soil accumulations of consequence, however. Although scores of mostly mild seismic shocks were recorded in 1986, volcanic eruptions ceased thousands of years ago. Sulfuric springs and steam vents, largely concentrated in the central and southern parts of the island, remain active, however. One of the largest springs, Boiling Lake, is located in the national park.

Dominica is water-rich with swift-flowing highland streams, which cascade into deep gorges and form natural pools and crater lakes. The streams are not navigable, but many are sources of hydroelectric power. Trafalgar Falls, located near the national park, is one of the most spectacular sites on the island. The principal rivers flowing westward into the Caribbean are the Layou and the Roseau, and the major one emptying eastward into the Atlantic is the Toulaman. The largest crater lake, called Boeri, is located in the national park.

Dominica has a tropical wet climate with characteristically warm temperatures and heavy rainfall. Excessive heat and humidity are tempered somewhat by a steady flow of the northeast trade winds, which periodically develop into hurricanes. The steep interior slopes also alter temperatures and winds. Temperature ranges are slight. Average daytime temperatures generally vary from 26°C in January to 32°C in June. Diurnal ranges are usually no greater than 3°C in most places, but temperatures dipping to 13°C on the highest peaks are not uncommon.

Most of the island's ample supply of water is brought by the trade winds. Although amounts vary with the location, rain is possible throughout the year, with the greatest monthly totals recorded from June through October. Average yearly rainfall along the windward east coast frequently exceeds 500 centimeters, and exposed mountainsides receive up to 900 centimeters, among the highest accumulations in the world. Totals on the leeward west coast, however, are only about 180 centimeters per year. Humidities are closely tied to rainfall patterns, with the highest values occurring on windward slopes and the lowest in sheltered areas. Relative humidity readings between 70 percent and 90 percent have been recorded in Roseau.

Hurricanes and severe winds, most likely to occur during the wettest months, occasionally are devastating. The most recent hurricanes of note were David and Frederick in August 1979 and Allen in August l980. The 1979 hurricanes caused over 40 deaths, 2,500 injuries, and extensive destruction of housing and crops. Many agricultural commodities were destroyed during the 1980 storm, and about 25 percent of the banana crop was demolished by strong winds in 1984.

Map references: Central America and the Caribbean

Area:
total: 754 km²
land: 754 km²

Coastline: 148 km

Maritime claims:
contiguous zone: 24 nm
exclusive economic zone: 200 nm
territorial sea: 12 nm

Land use:
arable land: 9%
permanent crops: 13%
permanent pastures: 3%
forests and woodland: 67%
other: 8% (1993 est.)

Irrigated land: NA km²

Natural hazards: Flash floods are a constant threat; destructive hurricanes can be expected during the late summer months

Environment - current issues: NA

Environment - international agreements:
Party to: Biodiversity, Climate Change, Desertification, Endangered Species, Environmental Modification, Hazardous Wastes, Law of the Sea, Ozone Layer Protection, Whaling

[edit] References

• This article contains material from the Library of Congress Country Studies, which are United States government publications in the public domain.
• This article contains material from the CIA World Factbook which, as a US government publication, is in the public domain.