map of Ghana. Ghana is characterized in general by low physical
relief. The
Precambrian rock system that underlies most of the nation has been worn down by erosion almost to a plain. The highest elevation in Ghana,
Mount Afadja in the
Akwapim-Togo Ranges, rises above sea level. There are four distinct geographical regions. Low plains stretch across the southern part of Ghana. To their north lie three regions—the Ashanti Uplands, the Akwapim-Togo Ranges, and the Volta Basin. The fourth region, the high plains, occupies the northern and northwestern sector of Ghana. Like most West African countries, Ghana has no natural harbours. Because strong surf pounds the shoreline, two artificial harbours were built at
Takoradi and
Tema (the latter completed in 1961) to accommodate Ghana's shipping needs.
Low plains The low plains comprise the four subregions of the coastal savanna, the
Volta Delta, the
Accra Plains, and the Akan lowlands or peneplains. A narrow strip of grassy and scrubby coast runs from a point near
Takoradi in the west to the
Togo border in the east. This coastal savanna, only about in width at its western end, stretches eastward through the Accra Plains, where it widens to more than , and terminates at the southeastern corner of the country at the lower end of the Akwapim-Togo Ranges. Almost flat and featureless, the Accra Plains descend gradually to the gulf from a height of about . The topography east of the city of Accra is marked by a succession of ridges and spoonshaped valleys. The hills and slopes in this area are the favoured lands for cultivation.
Shifting cultivation is the usual agricultural practice because of the swampy nature of the very lowlying areas during the rainy seasons and the periodic blocking of the rivers at the coast by sandbars that form lagoons. A plan to irrigate the Accra Plains was announced in 1984. Should this plan come to reality, much of the area could be opened to large-scale cultivation. To the west of Accra, the low plains contain wider valleys and rounded low hills, with occasional rocky headlands. In general, however, the land is flat and covered with grass and scrub. Dense groves of
coconut palms front the coastline. Several commercial centres, including Winneba, Saltpond, and Cape Coast are located here. Winneba has a small 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. The Volta Delta, which forms a distinct subregion of the low plains, extends into the
Gulf of Guinea in the extreme southeast. The delta's rock formation—consisting of thick layers of
sandstone, some
limestone, and
silt deposits—is flat, featureless, and relatively young. 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 numerous lagoons, some quite large, making road construction difficult. To avoid the lowest-lying areas the road between Accra and Keta makes a detour inland just before reaching Ada, and approaches Keta from the east along the narrow spit on which the town stands. Road links with Keta continue to be a problem. By 1989 it was estimated that more than 3,000 houses in the town had been swallowed by flooding from the lagoon. About 1,500 other houses were destroyed by erosion caused by the powerful waves of the sea. This flat, silt-composed delta region with its abundance of water supports
shallot,
corn, and
cassava cultivation in the region. The sandy soil of the delta gave rise to the
copra industry.
Salt-making, from the plentiful supply in the dried beds of the lagoons, provides additional employment. The main occupation of the delta people is fishing, an industry that supplies dried and salted fish to other parts of the country. The largest part of the low plains is the Akan Lowlands. Some experts prefer to classify this region as a subdivision of the
Ashanti Uplands because of the many characteristics they share. Unlike the uplands, the height of the Akan Lowlands is generally between sea level and . Some ranges and hills rise to about , but few exceed . The lowlands that lie to the south of the Ashanti Uplands receive the many rivers that make their way to the sea. The Akan Lowlands contain the basins of the
Densu River, the
Pra River, the
Ankobra River, and the
Tano River, all of which play important roles in the economy of Ghana. The Densu River Basin, location of the important urban centres of
Koforidua and
Nsawam in the eastern lowlands, has an undulating topography. Many of the hills here have craggy summits, which give a striking appearance to the landscape. The upper section of the Pra River Basin, to the west of the Densu, is relatively flat. The topography of its lower reaches resembles that of the Densu Basin and is a rich cocoa and food-producing region. The valley of the Birim River, one of the main tributaries of the Pra, is Ghana's most important diamond-producing area. 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. Here annual rainfall between helps assure a dense forest cover. In addition to timber, the area is rich in minerals. The Tarkwa goldfield, the diamond operations of the
Bonsa Valley, and high-grade manganese deposits are all found in this area. The middle and lower Tano basins have been intensely explored for oil and natural gas since the mid-1980s. The lower basins of the Pra, Birim, Densu, and Ankobra rivers are also sites for palm tree cultivation. Comprising the Southern Ashanti Uplands and the Kwahu Plateau, the Ashanti Uplands lie just 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. Stretching in a northwest-to-southeast direction, the Kwahu Plateau extends between Koforidua in the east and Wenchi in the northwest. The average elevation of the plateau is about , rising to a maximum of . The relatively cool temperatures of the plateau were attractive to Europeans, particularly missionaries, who founded many well-known schools and colleges in this region. The plateau forms one of the important physical divides in Ghana. 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. The plateau also marks the northernmost limit of the forest zone. Although large 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. The Southern Ashanti Uplands, extending from the foot of the Kwahu Plateau in the north to the lowlands in the south, slope gently from an elevation of about in the north to about in the south. The region contains several hills and ranges as well as several towns of historical and economic importance, including
Kumasi, Ghana's second largest city and former capital of the Asante.
Obuasi and
Konongo, two of the country's gold-mining centres, are also located here. The region is Ghana's chief producer of cocoa, and its tropical forests continue to be a vital source of timber for the lumber industry.
Volta Basin Taking the central part of Ghana, the Volta Basin covers about 45 percent of the nation's total land surface. Its northern section, which lies above the upper part of
Lake Volta, rises to a height of above sea level. Elevations of the Konkori Scarp to the west and the Gambaga Scarp to the north reach from . To the south and the southwest, the basin is less than . The Kwahu Plateau marks the southern end of the basin, and forms a natural part of the Ashanti Uplands. The basin is characterized by poor soil, generally of Voltaian
sandstone. Annual rainfall averages between . The most widespread vegetation type is
savanna, the woodlands of which, depending on local soil and climatic conditions, may contain such trees as red ironwood and shea. The basin's population, principally farmers, is low in density, especially in the central and northwestern areas of the basin, where tsetse flies are common. Archeological finds indicate that the region was once more heavily populated. Periodic burning occurred over extensive areas for perhaps more than a millennium, exposing the soil to excessive drying and erosion, rendering the area less attractive to cultivators. In contrast with the rest of the region are the
Afram Plains, located in the southeastern corner of the basin. Here the terrain is low, averaging in elevation, and annual rainfall is between and about . Near the Afram River, much of the surrounding countryside is flooded or swampy during the rainy seasons. With the creation of Lake Volta ( in area) in the mid-1960s, much of the Afram Plains was submerged. Despite the construction of roads to connect communities displaced by the lake, road transportation in the region remains poor. Renewed efforts to improve communications, to enhance agricultural production, and to improve standards of living began in earnest in the mid-1980s.
High plains The general terrain in the northern and northwestern part of Ghana outside the Volta Basin consists of a dissected plateau, which averages between in elevation and, in some places, is even higher. Rainfall averages between annually, although in the northwest it is closer to . Soils in the high plains are more arable than those in the Volta Basin, and the population density is considerably higher. Grain and cattle production are the major economic activities in the high plains of the northern region. Since the mid-1980s, when former United States President Jimmy Carter's Global 2000 program adopted Ghana as one of a select number of African countries whose local farmers were to be educated and financially supported to improve agricultural production, there has been a dramatic increase in grain production in northern Ghana. The virtual absence of tsetse flies in the region has led to increased livestock raising as a major occupation in the north. The region is Ghana's largest producer of cattle. ==Rivers and lakes==