Geography of Ghana
| Ghana | |
|---|---|
 | |
 | |
| Continent | Africa |
| Geographic coordinates | 8°00′N 2°00′W / 8.000°N 2.000°W |
| Area | Ranked 82nd |
| - Total | 238,533 square kilometres (92,098 sq mi) |
| - % water | 3.5% (8,520 square kilometres (3,290 sq mi)) |
| Coastline | 539 km |
| Highest point | Mount Afadja, 885 m |
| Lowest point | Atlantic Ocean, 0 m |
| Longest river | Volta |
| Largest inland body of water | Lake Volta |
| Land Use | |
| - Arable land | 20.66 % |
| - Permanent crops | 11.87 % |
| - Other | 67.48% (2012) |
| Irrigated land | 309 square kilometres (119 sq mi) (2003) |
| Climate | Tropical |
| Natural resources | industrial minerals, gold, timber, industrial diamonds, bauxite, manganese, fish, rubber, hydropower, petroleum, natural gas, silver, salt, limestone |
| Environmental issues | drought, deforestation, overgrazing, soil erosion, poaching, habitat destruction, water pollution |
Ghana is a country in West Africa, encompassing plains, hills, rivers, Lake Volta, the world's largest artificial lake, Dodi Island and Bobowasi Island on the south Atlantic Ocean coast. The Volta Basin takes up most of south-central Ghana and Ghana's highest point is Mount Afadja which is 885 m (2,904 ft) and is found in the Akwapim-Togo ranges.
Its southernmost coast at Cape Three Points is 4° 30' north of the equator.[1] From here, the country extends inland for some 670 kilometres (420 mi) to about 11° north.[1] The distance across the widest part, between longitude 1° 12' east and longitude 3° 15' west, measures about 560 kilometres (350 mi).[1] The Greenwich Meridian, which passes through London, traverses the eastern part of Ghana at Tema.[1]
Regions
The Precambrian rock system that underlies most of Ghana has been worn down by erosion almost to a plain.[1] The highest elevation in Ghana, Mount Afadja in the Akwapim-Togo Ranges, rises 880 metres (2,890 ft) above sea level.[1]
There are 4 regions.[1] Plains stretch across the southern part. To their north lie 3 regions—the Ashanti Uplands, the Akwapim-Togo Ranges, and the Volta Basin.[1] The fourth region, the high plains, occupies the northern and northwestern sector.[1] Like most West African countries, Ghana has no natural harbours.[1] Because surf pounds the shoreline, 2 artificial harbours were built at Takoradi and Tema (the latter completed in 1961) to accommodate shipping needs.[1]
Plains
The plains comprise the 4 subregions of the coastal savanna, the Volta Delta, the Accra Plains, and the Akan lowlands or peneplains.[1] A strip of grassy and scrubby coast runs from a point near Takoradi in the west to the Togo border in the east.[1] This coastal savanna, about 8 kilometres (5.0 mi) in width at its western end, stretches eastward through the Accra Plains, where it widens to more than 80 kilometres (50 mi), and terminates at the southeastern corner of the country at the lower end of the Akwapim-Togo Ranges.[1]
The Accra Plains descend gradually to the gulf from a height of about 150 metres (490 ft).[1] The topography east of the city of Accra is marked by a succession of ridges and spoonshaped valleys.[1] The hills and slopes in this area are the favoured lands for cultivation.[1] Shifting cultivation is an agricultural practice because of the swampy nature of areas during the rainy seasons and the periodic blocking of the rivers at the coast by sandbars that form lagoons.[1] A plan to irrigate the Accra Plains was announced in 1984.[1] Should this plan come to reality, an area could be opened to cultivation.[1]
To the west of Accra, plains contain wider valleys and rounded hills, with occasional rocky headlands.[1] In general, the land is flat and covered with grass and scrub.[1] Groves of coconut palms front the coastline.[1] Commercial centres, including Winneba, Saltpond, and Cape Coast are located here. Winneba has a livestock industry and palm tree cultivation is expanding in the area away from the coast, with the predominant occupation of the coastal inhabitants being fishing via dug-out canoe.[1]
The Volta Delta, which forms a subregion of the plains, extends into the Gulf of Guinea in the southeast.[1] The delta's rock formation consists of layers of sandstone, limestone, and silt deposits.[1] As the delta grew outward over the centuries, sandbars developed across the mouths of the Volta and smaller rivers that empty into the gulf in the same area, forming lagoons.[1]
To avoid the lowest-lying areas the road between Accra and Keta makes a detour inland before reaching Ada, and approaches Keta from the east along the spit on which the town stands.[1] Road links with Keta continue to be a problem.[1] By 1989 it was estimated that more than 3,000 houses in the town had been swallowed by flooding from the lagoon.[1] About 1,500 other houses were destroyed by erosion caused by sea waves.[1]
This flat, silt-composed delta region with its abundance of water supports shallot, corn, and cassava cultivation in the region.[1] The sandy soil of the delta gave rise to the copra industry.[1] Salt-making, from the supply in the dried beds of the lagoons, provides additional employment.[1] An occupation of the delta people is fishing, an industry that supplies dried and salted fish to other parts of the country.[1]
The largest part of the plains is the Akan Lowlands.[1] Some experts prefer to classify this region as a subdivision of the Ashanti Uplands because of characteristics they share.[1] Unlike the uplands, the height of the Akan Lowlands is generally between sea level and 150 metres (490 ft).[1] Some ranges and hills rise to about 300 metres (980 ft), and some exceed 600 metres (2,000 ft).[1] The lowlands that lie to the south of the Ashanti Uplands receive rivers that make their way to the sea.[1]
The Akan Lowlands contain the basins of the Densu River, the Pra River, the Ankobra River, and the Tano River.[1] The Densu River Basin, location of urban centres of Koforidua and Nsawam in the eastern lowlands, has an undulating topography.[1] The upper section of the Pra River Basin, to the west of the Densu, is "relatively flat".[1] The topography of its lower reaches resembles that of the Densu Basin and is a cocoa and food-producing region.[1] The valley of the Birim River, 1 of the tributaries of the Pra, is a diamond-producing area.[1]
The Ankobra River Basin and the middle and lower basins of the Tano River to the west of the lowlands form the largest subdivision of the Akan Lowlands.[1] Here annual rainfall between 1,500 and 2,150 millimetres (59 and 85 in) helps assure a forest cover.[1] In addition to timber, the area has minerals.[1] The Tarkwa goldfield, the diamond operations of the Bonsa Valley, and manganese deposits are found in this area.[1] The middle and lower Tano basins have been explored for oil and natural gas since the mid-1980s.[1] The lower basins of the Pra, Birim, Densu, and Ankobra rivers are sites for palm tree cultivation.[1]
Comprising the Southern Ashanti Uplands and the Kwahu Plateau, the Ashanti Uplands lie north of the Akan Lowlands and stretch from the Ivory Coast border in the west to the elevated edge of the Volta Basin in the east.[1] Stretching in a northwest-to-southeast direction, the Kwahu Plateau extends 193 kilometres (120 mi) between Koforidua in the east and Wenchi in the northwest.[1] The average elevation of the plateau is about 450 metres (1,480 ft), rising to a maximum of 762 metres (2,500 ft).[1] The "relatively cool" temperatures of the plateau were attractive to Europeans, particularly missionaries, who founded schools and colleges in this region.[1]
The plateau forms 1 of the physical divides.[1] From its northeastern slopes, the Afram and Pru Rivers flow into the Volta River, while from the opposite side, the Pra, Birim, Ofin, Tano, and other rivers flow south toward the sea.[1] The plateau marks the northernmost limit of the forest zone.[1] While areas of the forest cover have been destroyed through farming, enough deciduous forest remains to shade the head waters of the rivers that flow from the plateau.[1]
The Southern Ashanti Uplands, extending from the foot of the Kwahu Plateau in the north to the lowlands in the south, slope from an elevation of about 300 metres (980 ft) in the north to about 150 metres (490 ft) in the south.[1] The region contains hills and ranges.[1] Obuasi and Konongo, 2 of the country's gold-mining centres, are located here.[1] The region is a producer of cocoa, and its tropical forests continue to be a source of timber for the lumber industry.[1]
The general terrain in the northern and northwestern part outside the Volta Basin consists of a dissected plateau, which averages between 150 and 300 metres (490 and 980 ft) in elevation and, in some places, is higher.[1] Rainfall averages between 1,000 and 1,150 millimetres (39 and 45 in) annually, while in the northwest it is closer to 1,350 millimetres (53 in).[1] Soils in the higher plains are more arable than those in the Volta Basin, and the population density is higher.[1] Grain and cattle production are economic activities in the higher plains of the northern region.[1] Since the mid-1980s, when former United States President Jimmy Carter's Global 2000 program adopted Ghana as 1 of a select number of African countries whose local farmers were to be educated and financially supported to improve agricultural production, there has been an increase in grain production in northern Ghana.[1] The virtual absence of tsetse flies in the region has led to increased livestock raising as an occupation in the north.[1]
Volta Basin
Taking the central part, the Volta Basin covers about 45% of the total land surface.[1] Its northern section, which lies above the upper part of Lake Volta, rises to a height of 150 to 215 metres (492 to 705 ft) above sea level.[1] Elevations of the Konkori Scarp to the west and the Gambaga Scarp to the north reach from 300 to 460 metres (980 to 1,510 ft).[1] To the south and the southwest, the basin is less than 300 metres (980 ft).[1]
The basin is characterized by Voltaian sandstone.[1] Annual rainfall averages between 1,000 and 1,140 millimetres (39 and 45 in).[1] A vegetation type is savanna, the woodlands of which, depending on local soil and climatic conditions, may contain such trees as red ironwood and shea.[1] Periodic burning occurred over areas for more than a millennium, exposing the soil to drying and erosion, rendering the area less attractive to cultivators.[1]
In contrast with the rest of the region are the Afram Plains, located in the southeastern corner of the basin.[1] Here the terrain averages 60 to 150 metres (200 to 490 ft) in elevation, and annual rainfall is between 1,140 millimetres (45 in) and about 1,400 millimetres (55 in).[1] Near the Afram River, most of the surrounding countryside is flooded or swampy during the rainy seasons.[1] With the creation of Lake Volta (8,500 square kilometres (3,300 sq mi) in area) in the mid-1960s, most of the Afram Plains was submerged.[1] There are construction of roads to connect communities displaced by the lake.[1] Renewed efforts to improve communications, to enhance agricultural production, and to improve standards of living began in the 1980s.[1]
Rivers and lakes
Ghana is drained by a number of streams and rivers.[1] There are a number of coastal lagoons, man-made Lake Volta, and Lake Bosumtwi, southeast of Kumasi, which has no outlet to the sea.[1] In the wetter south and southwest areas, the river and stream pattern is denser, and in the area north of the Kwahu Plateau, the pattern is more open.[1] Streams and rivers dry up or experience reduced flow during the dry seasons of the year, while there is flooding during the rainy seasons.[1]
Drainage divide runs from the southwest part of the Akwapim-Togo Ranges northwest through the Kwahu Plateau and then irregularly westward to the Ivory Coast border.[1] Most of the rivers and streams north of this divide form part of the Volta system.[1] Extending about 1,600 kilometres (990 mi) in length and draining an area of about 388,000 square kilometres (150,000 sq mi), of which about 158,000 square kilometres (61,000 sq mi) lie within Ghana, the Volta and its tributaries, such as the Afram River and the Oti River, drain more than 2 thirds of Ghana.[1] To the south of the divide are smaller, independent rivers.[1] These include the Pra River, the Tano River, the Ankobra River, the Birim River, and the Densu River.[1] With the exception of smaller streams that dry up in the dry seasons or rivers that empty into inland lakes, some other rivers flow into the Gulf of Guinea directly or as tributaries to other rivers.[1] The Ankobra and Tano are navigable for distances in their lower reaches.[1]
Navigation on the Volta River has changed since 1964.[1] Construction of the dam at Akosombo, about 80 kilometres (50 mi) upstream from the coast, created the Lake Volta and the associated hydroelectric project.[1] Arms of the lake extended into the lower-lying areas, forcing the relocation of 78,000 people to newly created townships on the lake's higher banks.[1] The Black Volta River and the White Volta River flow separately into the lake.[1] Before their confluence was submerged, the rivers came together in the middle to form the Volta River.[1]
The Oti River and the Daka River, the principal tributaries of the Volta in the eastern part, and the Pru River, the Sene River, and the Afram River, tributaries to the north of the Kawhu Plateau, empty into flooded extensions of the lake in their river valleys.[1] Lake Volta is a source of fish, and its potential as a source for irrigation is reflected in an agricultural mechanization agreement signed in the 1980s to irrigate the Afram Plains.[1] The lake is navigable from Akosombo through Yeji in the middle.[1] A 24-metre (79 ft) pontoon was commissioned in 1989 to link the Afram Plains to the west of the lake with the lower Volta region to the east.[1] Hydroelectricity generated from Akosombo supplies Ghana, Togo, and Benin.[1]
On the other side of the Kwahu Plateau from Lake Volta are river systems, including the Pra, Ankobra, Tano and Densu.[1] The Pra is the easternmost and the largest of the 3 rivers that drain the area south of the Volta divide.[1] Rising south of the Kwahu Plateau and flowing southward, the Pra enters the Gulf of Guinea east of Takoradi.[1] In a part of the twentieth century, the Pra was used to float timber to the coast for export.[1] This trade is later carried by road and rail transportation.[1]
The Ankobra, which flows to the west of the Pra, has a drainage basin.[1] It rises in the region of Bibiani and flows in a southerly direction to enter the gulf west of Axim.[1] Craft can navigate approximately 80 kilometres (50 mi) inland from its mouth.[1] At 1 time, the Ankobra helped transport machinery to the gold-mining areas in the vicinity of Tarkwa.[1] The Tano, which is the westernmost of the 3 rivers, rises near Techiman in the centre of the country.[1] It flows in a southerly direction, and it empties into a lagoon in the southeast corner of Ivory Coast.[1] Navigation by steam launch is possible on the southern sector of the Tano for about 70 kilometres (43 mi).[1]
A number of rivers are found to the east of the Pra,[1] including Densu and Ayensu, both of which rise in the Atewa Range, and which are sources of water for Accra and Winneba respectively.[1] The country has a natural lake, Lake Bosumtwi, located about 32 kilometres (20 mi) southeast of Kumasi.[1] It occupies the steep-sided meteoric crater and has an area of about 47 square kilometres (18 sq mi).[1] A number of streams flow into Lake Bosumtwi, and there is no drainage from it.[1] Apart from providing an opportunity for fishing for local inhabitants, the lake serves as a tourist attraction.[1]
Climate
The climate has an annual mean temperature between 26 and 29 °C (79 and 84 °F).[2] Variations in the principal elements of temperature, rainfall, and humidity that govern the climate are influenced by the movement and interaction of the dry tropical continental air mass, or the harmattan, which blows from the northeast across the Sahara, and the opposing tropical maritime or moist equatorial system.[2] The cycle of the seasons follows the movement of the sun back and forth across the equator.[2]
During summer in the northern hemisphere, a maritime air mass intensifies and pushes northward.[2] A belt, or intertropical front, in the airmass brings warmer air, rain, and winds from the southwest.[2] As the sun returns south across the equator, the tropical continental front, or harmattan, prevails.[2] Climatic conditions across the country are "hardly uniform".[2] The Kwahu Plateau, which marks the northernmost extent of the forest area, serves as a climatic divide.[2] To its north, 2 seasons occur.[2] The harmattan season, with its drier, hotter days and cooler nights from November to March or April, is followed by a wetter period that reaches its peak in August or September.[2] To the south and southwest of the Kwahu Plateau, where the annual mean rainfall from north to south ranges from 1,250 to 2,150 millimetres (49 to 85 in), 4 separate seasons occur.[2] Rains fall from about April through June.[2] After a drier period in August, another rainy season begins in September and lasts through November, before the longer harmattan season sets in to complete the cycle.[2]
The extent of drought and rainfall varies across the country.[2] To the south of the Kwahu Plateau, the heaviest rains occur in the Axim area in the southwest corner of Ghana.[2] Farther to the north, Kumasi receives an average annual rainfall of about 1,400 millimetres (55 in), while Tamale in the drier northern savanna receives rainfall of 1,000 millimetres (39 in) per year.[2] From Takoradi eastward to the Accra Plains, including the lower Volta region, rainfall averages 750 to 1,000 millimetres (30 to 39 in) a year.[2]
The southern part is characterized by generally more humid conditions.[2] This is particularly so during the night, when 95 to 100% humidity is possible.[2] During the harmattan season, humidity drops as low as 25% in the north.[2]
Extreme points
This is a list of the extreme points, the points that are farther north, south, east or west than any other location.
- Northernmost point – the point at which the border with Burkina Faso enters the Morbira river south of the Burkinabè village of Kanhiré, Upper East Region
- Easternmost point – the southernmost section of the border with Togo, Volta Region*
- Southernmost point – Cape Three Points, Western Region
- Westernmost point - the point where the border with Ivory Coast enters the Manzan river, Western Region
- Note: Ghana does not have an easternmost point, the border at this section being defined along the line of longitude at 1°12'05.73"E[3]
See also
References
- ^ a b c d e f g h i j k l m n o p q r s t u v w x y z aa ab ac ad ae af ag ah ai aj ak al am an ao ap aq ar as at au av aw ax ay az ba bb bc bd be bf bg bh bi bj bk bl bm bn bo bp bq br bs bt bu bv bw bx by bz ca cb cc cd ce cf cg ch ci cj ck cl cm cn co cp cq cr cs ct cu cv cw cx cy cz da db dc dd de df dg dh di dj dk dl dm dn do dp dq dr
This article incorporates text from this source, which is in the public domain: Owusu-Ansah, David (1995). Berry, LaVerle (ed.). Ghana: a country study (3rd ed.). Washington, D.C.: Federal Research Division, Library of Congress. pp. 62–72. ISBN 0-8444-0835-2. OCLC 32508385.
- ^ a b c d e f g h i j k l m n o p q r s t This article incorporates text from this source, which is in the public domain: Owusu-Ansah, David (1995). Berry, LaVerle (ed.). Ghana: a country study (3rd ed.). Washington, D.C.: Federal Research Division, Library of Congress. pp. 72–73. ISBN 0-8444-0835-2. OCLC 32508385.
- ^ International Boundary Study, "Ghana Togo Boundary", No.126, 6 September 1972
