Physiography

Maldives consists of approximately 1,200 coral islands grouped in a double chain of twenty-seven atolls. Composed of live coral reefs and sand bars, these atolls are situated atop a submarine ridge 960 kilometers long that rises abruptly from the depths of the Indian Ocean and runs from north to south. Only near the southern end of this natural coral barricade do two open passages permit safe ship navigation from one side of the Indian Ocean to the other through the territorial waters of Maldives. For administrative purposes the Maldives government organized these atolls into nineteen administrative divisions..

Most atolls consist of a large, ring-shaped coral reef supporting numerous small islands. Islands average only one to two square kilometers in area, and lie between one and 1.5 meters above mean sea level. The highest island is situated at three meters above sea level. Maldives has no hills or rivers. Although some larger atolls are approximately fifty kilometers long from north to south, and thirty kilometers wide from east to west, no individual island is longer than eight kilometers.

Each atoll has approximately five to ten inhabited islands; the uninhabited islands of each atoll number approximately twenty to sixty. Several atolls, however, consist of one large, isolated island surrounded by a steep coral beach. The most notable example of this type of atoll is the large island of Fua Mulaku situated in the middle of the Equatorial Channel.

The tropical vegetation of Maldives comprises groves of breadfruit trees and coconut palms towering above dense scrub, shrubs, and flowers. The soil is sandy and highly alkaline, and a deficiency in nitrogen, potash, and iron severely limits agricultural potential. Ten percent of the land, or about 2,600 hectares, is cultivated with taro, bananas, coconuts, and other fruit. Only the lush island of Fua Mulaku produces fruits such as oranges and pineapples partly because the terrain of Fua Mulaku is higher than most other islands, leaving the groundwater less subject to seawater penetration. Freshwater floats in a layer, or "lens," above the seawater that permeates the limestone and coral sands of the islands. These lenses are shrinking rapidly on Male and on many islands where there are resorts catering to foreign tourists. Mango trees already have been reported dying on Male because of salt penetration. Most residents of the atolls depend on groundwater or rainwater for drinking purposes. Concerns over global warming and a possible long-term rise in sea level as a result of the melting of polar ice are important issues to the fragile balance between the people and the environment of Maldives in the 1990s.

Climate

The temperature of Maldives ranges between 24°C and 33°C throughout the year. Although the humidity is relatively high, the constant sea breezes help to keep the air moving. Two seasons dominate Maldives' weather: the dry season associated with the winter northeast monsoon and the rainy season brought by the summer southwest monsoon. The annual rainfall averages 2,540 millimeters in the north and 3,810 millimeters in the south.

The weather in Maldives is affected by the large landmass of the Indian subcontinent to the north. The presence of this landmass causes differential heating of land and water. Scientists also cite other factors in the formation of monsoons, including the barrier of the Himalayas on the northern fringe of the Indian subcontinent and the sun's northward tilt, which shifts the jet stream north. These factors set off a rush of moisture-rich air from the Indian Ocean over the subcontinent, resulting in the southwest monsoon. The hot air that rises over the subcontinent during April and May creates low-pressure areas into which the cooler, moisture-bearing winds from the Indian Ocean flow. In Maldives, the wet southwest monsoon lasts from the end of April to the end of October and brings the worst weather with strong winds and storms. In May 1991 violent monsoon winds created tidal waves that damaged thousands of houses and piers, flooded arable land with seawater, and uprooted thousands of fruit trees. The damage caused was estimated at US$30 million.

The shift from the moist southwest monsoon to the dry northeast monsoon over the Indian subcontinent occurs during October and November. During this period, the northeast winds contribute to the formation of the northeast monsoon, which reaches Maldives in the beginning of December and lasts until the end of March. However, the weather patterns of Maldives do not always conform to the monsoon patterns of the Indian subcontinent. Rain showers over the whole country have been known to persist for up to one week during the midst of the dry season.