Geography of the Gambia

Map of Gambia

Gambia is located on the west coast of the African continent and is 11,295 square kilometers whose smallest territorial state . The approximately 740 kilometers long border, established in an agreement between France and England in 1888 and unchanged since 1891 , follows the course of the Gambia River for a length of 480 km and a width between 10 and 50 km . Apart from the coastline, the Gambia is enclosed by Senegal, which is twenty times larger . The country is often referred to as an enclave , but this is incorrect by definition.

Surface shape

The surface shape of the Gambia

The country is determined by the Gambia River, which flows from east to west. The river landscape is surrounded by low laterite hills on both banks . 78 percent of the Gambia lies between sea level and 20  m above sea level . Based on the relief, one can roughly divide the country into three areas:

The valley floor is the area along the river and its tributaries. This area, which covers about 4048 km², 39 percent of the country, is characterized by the poorly draining sediment deposits . Seasonal floods are therefore common . This combination of the low location and the abundant water creates unique habitats. Only salt-tolerant mangroves grow on the loamy and salty soils of the estuary affected by brackish water ; they are joined by swamps , Faro on Mandinka , which extend the path to the river by more than two kilometers. In the middle third of the country, the river is accompanied by rice-growing areas as far as Janjanbureh Island . This area is called by the Mandinka Banto Faros (beyond the swamps), is often only lightly alluvial and fertile. The natural vegetation in this area is dominated by swamp grass.

Satellite image of the Gambia

The up to 21 meters high plateau is determined by the flat, iron-containing sand hills, which alternate with the depressions and form a cliff at Cape St. Mary and a coastal strip from Bakau to Fajara . In the central and eastern Gambia, the plateau is interrupted by laterite hills . The natural vegetation in this zone extends from individual trees to the savannah , and in the northeast to the tropical gallery forest in the southwest. As in Senegal, the peanut cultivation fell victim to all of the natural vegetation, with the exception of a few parcels used for forestry, so that the north bank shows bare areas on which desertification is taking full effect. In addition to peanuts, which are the only agricultural product exported, millet is also grown.

Around 400 of the 11,420 square kilometers are above 50  m above sea level and form a sandstone plain with rocky, bare hills in the east of the Gambia. The Gambia reaches its greatest height at 53  m above sea level in the Upper River Region in the eastern part of the country right on the border with Senegal.

Only one isolated hill with name is marked on maps: the approximately 29 meters high Mamayungebi Hill in the Central River Region , around which the Gambia River draws a loop .

See also : List of surveys in Gambia

geology

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The geological origins of Gambia are in the tertiary and quaternary geological ages; so the soil is relatively young. The Gambia is part of the tertiary continental plateau, which comprises 53 percent of the land area with alluvial Quaternary deposits along the Gambia river of the same name. Occasional marine invasion and terrestrial sedimentation and the formation of sandstone characterize the geology of the country. Iron deposits were created by the rainy and dry seasons during the Pleistocene .

The Tertiary rock formations comprise the layers from the Oligocene , Miocene and Pliocene and are part of the African Plate . These layers consist of sand, sandstone, silt, clay and kaolin . The ages of the strata are estimated to be 2.5 million years for the Oligocene to 33 million years for the Pliocene.

The Quaternary rock formations are very new rock formations in the geological age and less than 1.6 million years old. This group consists of six rock formations from two epochs, the Holocene and the Pleistocene . The Holocene strata are less than 8,000 years old, while the slightly older Pleistocene strata are estimated to be around 1.6 million years old. The geological layers along the river from the Holocene era are mainly alluvial deposits of coarse sand and silt, in the coastal zone of sandstone and silt. In eastern Gambia, the Quaternary rock formations away from the river consist of ferrous stone and pebble.

climate

Climate diagrams from west to east
Banjul	Janjanbureh	Basse Santa Su

The climate is tropical with a distinct rainy season and dry season . The dry season lasts from November to May and is influenced by the dry northeast wind from the Sahara , called Harmattan . The temperatures rise to values ​​between 21 and 27 ° C, the relative humidity remains in the range between 30 and 60 percent.

The summer rainy season starts in June and lasts until October. The average annual rainfall is 1000 mm in the southwest and 800 mm in the northeast. Most of the rain, almost 90 percent, falls in the months between July and September. Near the coast, for example in Kombo-St. Mary Area , the oceanic climate is more pleasant.

Waters

The coastal erosion on graves

The Gambia near Janjanbureh

The Gambia at the Baboon Islands

A part of the coast that is threatened by erosion

The Gambia lies on the Atlantic Ocean and has a coastline of approximately 80 kilometers in length.

The erosion of the various sections of the beach during storms causes major problems . In Banjul is a cemetery in danger of being completely swallowed by the sea. A large number of graves have already been destroyed by the sea. At Kololi , in the tourist center of Kololi Beach , the beach sections of the Senegambia Beach Hotel and the Kairaba Beach Hotel had to be painstakingly renewed. This was done using sand from the seabed, which was pumped to the coast by dredgers through steel pipes.

About 1300 km², i.e. 11.5 percent of the country's area, are bodies of water. The Gambia River - one of the main rivers in Africa - with its side arms carries the majority of this. The Bintang Bolong is the largest tributary of these. Bolong is a word for "moving water" or "tributary" in the Mandinka language . The names of most of the tributaries of the Gambia have the suffix Bolong.

There are also the River Benifet and the Tanji , which flows into the Atlantic Ocean near Tanji . The Allahein , which also flows into the Atlantic, is the border river to the southern Senegalese region of Casamance for about ten kilometers .

See also : List of waters in Gambia

Islands

All of the country's major islands are in the Gambia River, including the small island of James Island . It is of great historical importance as it is recognized as a World Heritage Site with Fort James . The 585 hectare large River Gambia National Park located in the archipelago Baboon Islands . In 1979 , chimpanzees that had previously been kept in the Abuko Nature Reserve were reintroduced into this reserve . The city ​​of Janjanbureh , formerly known as Georgetown, is located on Janjanbureh Island .

In the Atlantic Ocean, Bijol Islands is the only small group of islands off the coast of Gambia. It is known and protected as a bird paradise near the coastal town of Tanji .

See also : List of islands in Gambia

Cities

The five largest cities and towns included in the 2013 calculation are:

1. Serekunda with 362,986 inhabitants, which is the economic and cultural center of the country
2. Brikama with 84,608 inhabitants
3. Bakau with 53,766 inhabitants
4. Lamin with 39,183 inhabitants
5. Nema Kunku 36,134 inhabitants

See also : List of localities in Gambia

Individual evidence

1. ↑ Malanding S. Jaiteh, Baboucarr Sarr: Climate Change and Development in the Gambia: Challenges to Ecosystem Goods and Services . Pp. 1-3. Elevation data based on: The Gambia 50,000 database 2003 topographic data. Department of Local Government and Lands.
2. ↑ Global Environment Facility , United Nations Environment Program (Ed.): The Gambia's Second National Communication under the United Nations Framework Convention on Climate Change . Banjul, November 2012, p. 32.
3. ^ The World Factbook : The Gambia . Geography section and map . Retrieved July 30, 2019.
4. ↑ on bevoelkerungsstatistik.de (no longer available online, last accessed May 2013)

literature

• Bernd Wiese: Senegal, Gambia, countries in the Sahel-Sudan zone. Klett-Perthes, Gotha 1995, ISBN 3-623-00664-5