Mauritius

PHYSICAL ENVIRONMENT

Geography

Mountain view in Mauritius
Courtesy Mari G. Borstelmann

The island of Mauritius lies about 800 kilometers east of Madagascar between longitudes 57 18' and 57 49' east, and latitudes 19 59' and 20 32' south. Pearl-shaped, it is sixty-one kilometers long and forty-six kilometers wide at the extremes and has a total land area of some 1,865 square kilometers--about the size of Rhode Island. Mauritian territory also incorporates the island of Rodrigues, some 600 kilometers to the east, which is 119 square kilometers in area. Two tiny dependencies to the north of Mauritius, the Agalega Islands and the Cargados Carajos Shoals (also known as the St. Brandon Rocks), are unpopulated (see Mauritius - fig. 5). Nonetheless, their location permits the nation's exclusive economic zone (EEZ--see Glossary) to cover about 1.2 million square kilometers of the Indian Ocean. Just off the Mauritian coast lie some twenty uninhabited islands. Mauritius and France both claim sovereignty over Tromelin, small islands that lie 483 kilometers to the northwest. Mauritius sought to regain sovereignty, lost just before independence in 1968, over the Chagos Archipelago (1,931 kilometers to the northeast), which includes the Diego Garcia atoll.

Mauritius and Rodrigues are part of the Mascarene Islands, a chain of volcanic islands that include Reunion, the nation's nearest neighbor at 145 kilometers to the southwest and governed as an overseas territory (département) of France. The islands are perched on submarine ridges, including the Mascarene Plateau that runs for some 3,000 kilometers in an arc bowed outward from the African mainland, and the Rodrigues Fracture Zone that ripples eastward and connects this underwater plateau with the massive Mid-Indian Ridge.

Mauritius is relatively young geologically, having been created by volcanic activity some 12 million years ago. There has been no active volcano on the island for more than 100,000 years. The island consists of a broken ring of mountain ranges, some 600 to 800 meters above sea level, encircling a central tableland that slopes from a level of 300 meters in the north to 600 meters in the southwest. The mountains are surrounded by low-lying, sometimes hilly, coastal plains, except in the southwest where the drop-off is precipitous. The mountains are steepest toward the center of the island and are probably the tips of the eroded original shield volcano. The sea has built up a ring of coral reefs around most of the 160 kilometers of coastline, which form many shallow lagoons, white coral sand beaches, and dunes. Two of the best harbors are Port Louis and Mahebourg. Politically, the island is divided into eight administrative divisions called districts and one municipality where the capital, Port Louis, is located.

Lowland plains and gently undulating slopes cover about 46 percent of the total land area. Low-lying plains make up most of the Pamplemousses, Rivière du Rempart, and Flacq districts; southern Grand Port District; the heavily populated northwestern section of Plaines Wilhems District from Beau Bassin to Quatre Bornes and to the sea; and smaller areas around Chemin Grenier. These areas are planted with sugarcane and mixed vegetable crops. The districts of Port Louis and Black River and the more hilly interior plains leading up to the tableland support tea, rice, and sugarcane cultivation and include areas of savanna and scrub forest.

The central tableland covers about a quarter of the island. A large plateau spans most of the districts of Moka, eastern Plaines Wilhems, and western Grand Port, where mostly sugarcane and vegetables are harvested, except around Curepipe and Vacoas, where tea is grown. The southern part of the tableland--in the districts of Black River, Savanne, and southern Plaines Wilhems-- is much smaller and heavily dissected with a diverse topography. It contains tea and forest plantations, including reserves of indigenous trees.

Mountains cover about 18 percent of the terrain. The MokaLong Mountain Range is situated in the northwest near Port Louis, and its highest peak is Pieter Both (823 meters). The Rivière Noire Mountains and Savanne Mountains are in the west and southwest, where Mont Piton of the Petite Rivière Noire (828 meters) is the highest point on the island. The mountains are broken into four ridges that produce deep valleys, gorges, and waterfalls. The Grand Port Range lies in the east, and to its north are the isolated Mont Blanche (520 meters) and Fayences Mountain (425 meters).

Rivers and streams dot the island; many of them are formed in the crevices between land created by new and old lava flows. Drainage radiates from the central tableland to the sea, and many rivers are steeply graded with rapids and falls. Torrential flows are common during storms and cyclones. Marshes and ponds lie in the tableland and on the coastal plain, but the country has only two natural lakes, both crater lakes. The largest of several manmade reservoirs is the Mare aux Vacoas.

Rodrigues Island was formed earlier than Mauritius, but in a similar fashion. It sits lengthwise on an east-west axis, along which runs a spine-like mountain range some 600 meters above sea level. The north-south spurs of these mountains cut deep crevices into the terrain.

The other dependencies of Mauritius are coralline rather than volcanic islands. The two Agalega islands are connected by a sandbar and covered with coconut palms. The Cargados Carajos Shoals are a group of more than twenty islands, none more than one square kilometer in area, which are primarily fishing stations.

Data as of August 1994

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