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Ivory Coast - GEOGRAPHY
Côte d'Ivoire lies on the West African coast on the Gulf of Guinea. Its outline is roughly that of a square 560 kilometers on a side, with an area of 322,460 square kilometers-- nearly the same as New Mexico. It is bounded on the east by Ghana, on the north by Burkina Faso and Mali, and on the west by Guinea and Liberia. The entire southern border is Gulf of Guinea coastline.
The nation consists of a large plateau rising gradually from sea level to almost 500 meters altitude in the north. Vegetation changes from lagoon and semitropical growth in the south to savanna grassland and scrub in the north. Mountain ranges extend along the western border and a few peaks dot the northeast corner. Four major river systems flow southward forming parallel drainage basins. Cutting across these basins are three geographic regions roughly parallel to the coast--the lagoon region, the forest region, and the savanna region.
The lagoon region (zone lagunaire) is a narrow coastal belt extending along the Gulf of Guinea from the Ghana border to the mouth of the Sassandra River. It consists of a strip of low, sandy islands and sandbars built by the combined action of heavy surf and ocean currents. These sand barriers, known as the cordon littoral, have almost closed the rivers flowing into the gulf. The resulting series of lagoons ranges in width from about a hundred meters to seven or eight kilometers and seldom rises more than thirty meters above sea level, leaving the area subject to frequent flooding during rainy seasons.
Most of the lagoons are narrow, salty, and shallow and run parallel to the coastline, linked to one another and the gulf by small watercourses or canals. Where large rivers empty into the gulf, broad estuaries extend as much as ten to twenty kilometers inland. The sandy soil supports the growth of coconut palms and salt-resistant coastal shrubs. The dense rain forest that once came down to the water's edge along the continental side of the lagoons has been largely supplanted by clearings for farms and towns and by second-growth woodlands. In the few remaining undisturbed areas, dense mangrove thickets appear along the edges of marshy inlets.
A broad belt of dense forest covers nearly one-third of the country, extending north of the lagoon region in the east and reaching down to the coastline in the west between the Sassandra River and the mouth of the Cavally River. Its northern boundary stretches from the city of Man in the west to Bondoukou in the east, dipping down in the center of the country to the confluence of the Bandama Blanc and Bandama Rouge rivers. This boundary marks the transition from forest to grassy woodlands where plantation agriculture and burning have encroached on the forest. From the border with Ghana west to the Sassandra River, the gently rolling relief of the forest region is broken by small hills. West of the Sassandra, the Dan Mountains and the Toura Mountains reach 1,300 meters elevation. Mt. Nimba, near the border with Liberia and Guinea, reaches 1,752 meters.
The northern half of the nation is generally characterized as savanna--a large plateau consisting primarily of rolling hills, low-lying vegetation, and scattered trees. Vegetation varies from woodlands to grasslands and occasional patches of dry scrub in the far north. Some narrow strips of forest extend toward the north along watercourses and drainage lines. The southern portion of the savanna is sometimes referred to as the transition zone (zone de transition) and the northern portion as the sudanic zone (zone soudanienne), although the entire region is transitional between the narrow belt of forest paralleling the coastline and the Sahara Desert. The gently rolling plains are broken occasionally by granite domes or small hill masses, the most extensive being the Komonos Hills. In the northwest, a number of peaks exceeds 800 meters elevation.
A major divide extends across the northeastern corner of Côte d'Ivoire near Burkina Faso, separating the main southward drainage system from the Volta River Basin, which drains to the north. Near Bondoukou, where the divide crosses the Ghana border, Mt. Bowé de Kiendi reaches 725 meters elevation. In the north, Mt. Yélévé reaches an altitude of 685 meters.
Four major river systems follow meandering courses from north to south, draining into the Gulf of Guinea. From west to east these are the Cavally, Sassandra, Bandama, and Comoé--all relatively untamed rivers navigable only short distances inland from the coast. In the north, many smaller tributaries change to dry streambeds between rains.
The Cavally River has its headwaters in the Nimba Mountains of Guinea and forms the border between Côte d'Ivoire and Liberia for over half its length. It crosses rolling land and rapids and is navigable for about fifty kilometers inland from its exit to the sea near Cape Palmas.
The Sassandra River Basin has its source in the high ground of the north, where the Tiemba River joins the Férédougouba River, which flows from the Guinea highlands. It is joined by the Bagbé, Bafing, Nzo, Lobo, and Davo rivers and winds through shifting sandbars to form a narrow estuary, which is navigable for about eighty kilometers inland from the port of Sassandra.
The Bandama River, often referred to as the Bandama Blanc, is the longest in the country, joining the Bandama Rouge (also known as the Marahoué), Solomougou, Kan, and Nzi rivers over its 800-kilometer course. This large river system drains most of central Côte d'Ivoire before it flows into the Tagba Lagoon opposite Grand-Lahou. During rainy seasons, small craft navigate the Bandama for fifty or sixty kilometers inland.
Easternmost of the main rivers, the Comoé, formed by the Leraba and Gomonaba, has its sources in the Sikasso Plateau of Burkina Faso. It flows within a narrow 700-kilometer basin and receives the Kongo, and Iringou tributaries before winding among the coastal sandbars and emptying into the Ebrié Lagoon near Grand-Bassam. The Comoé is navigable for vessels of light draft for about fifty kilometers to Alépé.
Large dams were built in the 1960s and 1970s to control the flow of major rivers to the south. These projects created reservoirs, now referred to as lakes bearing the names of the dams- -Buyo on the Sassandra, Kossou and Taabo on the Bandama, and Ayamé on the small Bia River in the southeast corner of the country. Lake Kossou is the largest of these, occupying more than 1,600 square kilometers in the center of the country.
The climate is generally warm and humid and is, overall, transitional from equatorial to tropical. Seasons are more clearly distinguishable by rainfall and wind direction than by temperature. Continental and maritime air masses, following the apparent movement of the sun from north to south, determine the cycle of the seasons that is associated with heat and cold farther from the equator.
During the first half of the year, the warm maritime air mass pushes northward across Côte d'Ivoire in response to the movement of the sun. Ahead of it, a low pressure belt, or intertropical front, brings warm air, rain, and prevailing winds from the southwest. As the solar cycle reverses at midyear, the continental air mass moves southward over the nation, permitting the dry northeast harmattan to dominate. Surface winds are gentle, seldom exceeding fifteen to twenty kilometers per hour.
Two climatic zones are created by the alternating wind patterns. In the north, tropical conditions delineate two major seasons. Heavy rains fall between June and October, averaging 110 centimeters annually. Along the coast, equatorial conditions prevail. Some rain falls in most months, with an average of 200 centimeters annually, but four seasons are generally distinguishable. Heavy rains fall between May and July in most years, and shorter rains during August and September. The minor dry season still brings sparse rainfall during October and November, followed by the major dry season from December to April.
Temperatures and humidity generally follow the same pattern, with average temperatures between 25° C and 30° C and ranges from 10° C to 40° C. Temperatures are higher in the south but may exceed 30° C even in the far north. Annual and daily ranges of both temperature and humidity are small along the coast but increase progressively toward the north. The average relative humidity is 85 percent in the south and 71 percent in the north.