Geography of Ghana

Relief Map of Ghana

The geography of Ghana is characterized by an overall relatively flat relief. About half of the whole country is no higher than 150 meters. On average, Ghana is at an altitude of 450 meters above sea level. A mountain range can only be found on the border with Togo , which runs consistently just below the height of 900 meters and extends as far as Togo. A total of five different geographical regions can be distinguished.

The climate in Ghana is characterized by its proximity to the equator . From the coast to the center of the country there is a humid tropical climate. The vegetation in the form of tropical rainforest is also densest here. The north of the country is strongly influenced by the dry continental air currents from the Sahara . The center of the country is already to be seen as a tree savannah , in the north it turns into dry steppe. The annual average temperature moves regularly between 26 ° C and 29 ° C, with an annual precipitation of 2100 mm in the southwest of the country and of approx. 1000 mm in the north.

location and size

Ghana lies over a length of approx. 540 km on the Gulf of Guinea , i.e. directly on the Atlantic . The geographical position is given as 4 ° 45 'to 11 ° 10' north latitude and 3 ° 15 'west to 1 ° 12' east. The so-called prime meridian , which also runs through Greenwich near London , cuts Ghana near the city of Tema , a little east of Accra , the capital of Ghana. In addition, the equator is only about 540 km south of the coast of Ghana, which gives Ghana almost equally long days and nights.

Ghana thus extends in north-south direction over a distance of approx. 700 km, in east-west direction over approx. 450 km, almost in a rectangle. This means that Ghana covers an area of 238,537 km² and is roughly the size of the old colonial power Great Britain or the old Federal Republic of Germany. However, the long coast of Ghana has no natural harbor. With Takoradi , Ghana got its first man-made port from the colonial power. In 1961 the second of the two artificial harbors in Tema was completed.

The natural areas of Ghana

Coastal plain with a sandy beach

Roughly speaking, Ghana has three geographical zones: the coastal plain, the rainforest zone and the savannah. Due to the additional possible subdivision according to the surface structure, Ghana is geographically divided into five natural areas:

All natural spaces differ considerably from one another and have different vegetation and fauna. An important differentiating criterion for the individual zones is the amount of precipitation.

climate

Ghana is a tropical country in close proximity to the equator , which runs about 540 km south of the coast. Ghana does not have four seasons , only the dry season and the rainy season . As a tropical country, Ghana has an average air temperature of 28–32 ° C. However, the north of the country usually has higher average temperatures due to the influence of the dry and warm desert winds. This is also the place that keeps the temperature record in Ghana with 42.2 ° C, the city Navrongo . There are also greater temperature differences in the north of the country than in the south. In Kumasi and in Tafo (some say a district of Kumasi, others see Tafo in the immediate vicinity of Kumasi as a separate city) the lowest temperature in Ghana has been measured so far at 12 ° C.

The climatic conditions, for example with regard to temperature and rainfall, are largely determined by the movement of the dry tropical continental air mass from the Sahara and the tropical maritime air mass over the Atlantic . The continental wind from the Sahara prevails during the dry season and is also called harmattan in Ghana .

Due to the tropical climate, the rainfall in Ghana cannot be compared with the rain in moderate climates , but almost always occurs with great violence, similar to a downpour. It is not uncommon for the soil to be unable to absorb the masses of water, flooding is the result, which often cost people their lives in larger cities and in Accra . The heaviest rainfall is in the area around Axim in the south-west of the country. Kumasi , Ghana's second largest city, located in the middle of the Ashanti highlands, has an average rainfall of 1400 mm. Tamale , located in the north in the northern Volta Basin , has to get by with 1000 mm of precipitation per year. In the coastal plain between Takoradi in the west and the Volta Delta, the average rainfall is only 750–1000 mm per year.

Rainy seasons prevail in Ghana from April to June and September / October . The air humidity is then about 90%, because at this time the dominant wind direction is blowing the air, almost saturated with water, from the Atlantic over the country. Immediately before this monsoon rain, the highest temperatures are measured in Ghana. The months immediately between the rainy months (July and August) are the coldest in the coastal plain in Ghana. The rain often comes down in the afternoon.

In the dry season , from November to February , the whole country is dominated by the harmattan coming from the Sahara , a trade wind blowing from the northeast . The temperature differences between day and night are greater, the average temperature drops to 25–27 ° C during these months, and at night it can even be almost 20 ° C. In northern Ghana, the nights can even cool down to 15 ° C. Fine sand from the Sahara is in the air during the dry season. Every year billions of tons of it are distributed across the country from the desert areas north of Ghana. During the dry season, the humidity drops to up to 25%.

Waters

Wli waterfall in the Volta region

Volta river

Rainforest in Kakum National Park seen from the Canopy Walkway

Ghana is drained by a large number of different streams and rivers. A special feature of Ghana's water system is the Bosumtwi Lake, which, with its circular shape without a runoff, located a little south of Kumasi , not only has religious significance within the population, but also indicates a meteorite impact. In 1964, as the largest fully man-made dam at the time, Lake Volta became a milestone in the geography of Ghana and in supplying the population with water energy.

The Volta and its tributaries have a total length of 1,600 km and drain the entire north and center of Ghana so a total of approx. 388,000 km², of which more than half (158,000 km²) are in Ghana (area: 238,537 km²). In the highlands of Ashanti there are also a large number of rivers that drain south into the Atlantic . They include the Pra with its tributaries, Anum , Birim and Offin . In addition to the Pra system, the Bia , Tano , Densu and Ankobra also flow through the south of Ghana as larger independent rivers.

With the exception of the smaller rivers, these usually do not dry out in the dry season, but carry water all year round. Ankobra and Tano are largely navigable by ship.

Division of the country into its catchment areas

Rivers	km²	Percent of the country's area
Volta	167,692	70.3
Pre	22,106	9.3
Tano	13,950	5.8
Ankobra	8,403	3.5
Densu	2,490	1.0
More rivers	23,896	10.0
total	238,537	100

Individual evidence

[VB-1] IWMI - The Volta River Basin (2005)

[2] FAO - The Niger River basin

[3] Water Resources Commission (WRC) Ghana