Geography of Madagascar

Land coverage (left) and topographical (right) maps of Madagascar

Madagascar can be divided into five general geographical regions: the east coast, the Tsaratanana Massif, the Central Highlands, the west coast, and the southwest. The highest elevations parallel the east coast.[3] The total size is 587,040 square kilometres (226,660 sq mi), which makes it the world's second largest island country.[1]

Central Highlands

Village in the central highlands

The Central Highlands, which range from 800 to 1,800 m (2,625 to 5,906 ft) in altitude, contain a wide variety of topographies: rounded and eroded hills, massive granite outcrops, extinct volcanoes, eroded peneplains, and alluvial plains and marshes, which have been converted into irrigated rice fields. The Central Highlands extend from the Tsaratanana Massif in the north to the Ivakoany Massif in the south. They are defined rather clearly by the escarpments along the east coast, and they slope gently to the west coast. The Central Highlands include the Anjafy High Plateaux; the volcanic formations of Itasy (Lake Itasy is in a volcanic crater) and the Ankaratra Massif, reaching a height of 2,643 m (8,671 ft). The Isalo Roiniforme Massif lies between the central highlands and the west coast.[3]

Antananarivo, the national capital, is located in the northern portion of the Central Highlands at 1,276 m (4,186 ft) above sea level. A prominent feature of the Central Highlands is a rift valley running north to south, located east of Antananarivo and including Lac Alaotra, the largest body of water on the island. The lake is located 761 m (2,497 ft) above sea level and is bordered by two cliffs, rising 701 m (2,300 ft) to the west and 488 m (1,601 ft) to the east, which form the walls of a valley. This region has experienced geological subsidence, and earth tremors are frequent.[3]

The Mananara and Mangoro rivers flow from the Central Highlands to the east coast, as does the Maningory, which flows from Lake Alaotra. Other rivers flowing east into the Indian Ocean include the Bemarivo, the Ivondro, and the Mananjary. These rivers tend to be short because the watershed is located close to the east coast. Owing to the steep elevations, they flow rapidly, often over spectacular waterfalls.

The rivers flowing to the west coast discharge into the Mozambique Channel and tend to be lengthier and have a lesser gradient. The major rivers on the west coast are the Sambirano, the Mahajamba, the Betsiboka (part of Mahajanga is located at the mouth), the Mania, the North and South Mahavavy, the Mangoky, and the Onilahy. The Ikopa, which flows past Antananarivo, is a tributary of the Betsiboka. The Onilahy, located in the driest part of the island, occasionally dries up during droughts.

Important lakes, aside from Alaotra, include Lake Kinkony in the northwest, Lake Itasy in the center and Lake Ihotry in the southwest.

• 
  Majahilo river at Miandrivazo
• 
  This astronaut photograph highlights two estuaries along the north-western coastline of Madagascar
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  Tsiribihina River
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  Lake Tritiva

Madagascar map of Köppen climate classification zones

The climate is tropical along the coast, temperate inland, and arid in the south. The weather is dominated by the southeastern trade winds that originate in the Indian Ocean anticyclone, a center of high atmospheric pressure that seasonally changes its position over the ocean. Madagascar has two seasons: a warm, wet season from November to April; and a cooler, dry season from May to October. There is, however, great variation in climate owing to elevation and position relative to dominant winds. Overall, surface water is most abundant along the east coast and in the far north (with the exception of the area around Cap d'Ambre, which has relatively little surface water). Amounts diminish to the west and south, and the driest regions are in the extreme south.

The east coast has a tropical rainforest climate; being most directly exposed to the trade winds, it has the highest rainfall, averaging as high as 4,000 mm (157.5 in) annually in some places. This region has a hot, humid climate in which tropical fevers are endemic. Destructive cyclones occur during the rainy season, coming in principally from the direction of the Mascarene Islands. Because rain clouds discharge much of their moisture east of the highest elevations on the island, the Central Highlands are drier and, owing to the altitude, also cooler. Thunderstorms are common during the rainy season in the Central Highlands and the eastern coastal lowlands.

Antananarivo receives practically all of its average annual 1,400 mm (55.1 in) of rainfall between November and April. The dry season is sunny, although somewhat chilly, especially in the mornings. Although frosts are rare in Antananarivo, they are common at higher elevations. Hail is common in many of the higher areas of the island (including Antananarivo), but there is no snowfall except on the Ankaratra massif where above 2,400 m (7,874 ft) it may occasionally fall and even remain for several days.

The west coast is drier than either the east coast or the Central Highlands because the trade winds lose their humidity by the time they reach this region. The southwest and the extreme south are semidesert; as little as 330 mm (13 in) of rain falls annually at Toliara.

Climate change

This section is an excerpt from Climate change in Madagascar.[edit]

Satellite image of Cyclone Batsirai approaching Madagascar. Tropical cyclones will become more intense in the country due to climate change.

Climate change in Madagascar is a significant threat to the country's environment and people. Climate change is resulting in average temperatures in Madagascar becoming hotter, with longer dry seasons and more intense tropical storms. The country's unique ecosystems, animal and plant life are being impacted. Madagascar's population is highly vulnerable due to severe impacts on water and agriculture in Madagascar, with implications for food security and health.

Baobabs near Morondava

The island of Madagascar has been described as an "alternate world" or a "world apart" because of the uniqueness and rarity of many of its plant and animal species. Their characteristics are believed to reflect the island's origins as a part of Gondwanaland and its many millions of years of isolation following the breakup of the landmass.

Many of the characteristic African species—large mammals such as the elephant, rhinoceros, giraffe, zebra, and antelope and predators such as lions and leopards—do not exist in Madagascar. In addition, the island has been spared the great variety of venomous snakes indigenous to the African continent. Although it is assumed that most life forms on the island had an African (or South American) origin, isolation has allowed old species—elsewhere extinct—to survive and new species unique to the island to evolve. Thus, a great number of plant, insect, reptile, and fish species are endemic to Madagascar, and all indigenous land mammal species—66 in all—are unique to the island.

Madagascar was once covered almost completely by forests, but slash and burn practices for dry rice cultivation has denuded most of the landscape, especially in the Central Highlands. Rain forests are concentrated on the steep hillsides along a slender north-south axis bordering the east coast, from the Tsaratanana Massif in the north to Tolagnaro in the south. Secondary growth, which has replaced the original forest and consists to a large extent of traveller's trees, raffia palm, and baobabs, is found in many places along the east coast and in the north. The vegetation of the Central Highlands and the west coast is for the most part savanna or steppe, and coarse prairie grass predominates where erosion has not exposed the orange-red lateritic soil. In the southwest, the vegetation is adapted to desert conditions.

The remaining rain forest contains a great number of unique plant species. The country has some 900 species of orchid. Bananas, mangoes, coconut, vanilla, and other tropical plants grow on the coasts, and the eucalyptus tree, brought from Australia, is widespread today.

Wood and charcoal from the forests are used to meet 80% of domestic fuel needs. As a result, wood has become scarce. In 1990, the World Bank launched an environmental program that has increased the planting of pine and eucalyptus to satisfy fuel needs.

Madagascar has a number of natural resources, including graphite, chromite, coal, bauxite, rare Earth elements, salt, quartz, tar sands, semi-precious stones and mica. There are also fishing areas offshore and potential for hydropower. In 2011, it was estimated that 5.96% of the land area was used for arable land and 1.02% had permanent crops. Twenty-six percent of the land is forested. The majority of the population depends on subsistence farming, largely rice and cattle. The manufacturing sector is small but growing.

Madagascar is currently suffering in some areas from soil erosion as a result of deforestation and overgrazing, desertification, and contamination of surface water with raw sewage and organic waste. Several species of flora and fauna that are unique to the islands are endangered. Regular cyclones cause flooding in low-lying coastal regions.

This is a list of the extreme points of Madagascar, the points that are farther north, south, east or west than any other location.

• Northernmost Point - Cap D'Ambre, Antsiranana Province at 11°57′00″S 49°15′56″E
• Easternmost Point - Ile Ngontsy, Antsiranana Province at 15°15′48″S 50°29′36″E
• Easternmost point (mainland) - Cap Est, Antsiranana Province at 15°15′56″S 50°29′10″E
• Southernmost Point - Cape Vohimena (Cap Sainte Marie), Toliara Province at 25°36′24″S 45°10′02″E
• Westernmost Point - Nosy Hao, Toliara Province at 22°05′13″S 43°11′18″E
• Westernmost Point (mainland) - Pointe Mananonoka, Toliara Province at 22°15′04″S 43°13′13″E

• List of cities in Madagascar
• List of rivers of Madagascar
• Ecoregions of Madagascar
• Geographic data related to Geography of Madagascar at OpenStreetMap

•  This article incorporates public domain material from Peter J. Schraeder. Madagascar. Library of Congress Country Studies.

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