Mountain Ranges, Deserts and Landforms of Central African Republic

Geology

The Congo Basin is a large depression within the Congo Craton, making it a patch of relatively recent (Phanerozoic-aged, and mostly Mesozoic and onwards) sedimentary rock within a large, otherwise ancient (Archean-aged) piece of exposed continental crust. The deformation of the craton began as early as the late Cambrian or early Ordovician and continued over the Paleozoic, but the deformation over this period led to rapid erosion of much of the Paleozoic rock, creating a large unconformity. Sediment started to rapidly accumulate in the basin from the Mesozoic (Triassic) up to the present day.

Deposits throughout the Jurassic suggest the presence of a freshwater, lacustrine habitat in the basin, and this continued into the Early Cretaceous.

Climate

The Congo Basin is a globally important climatic region with annual rainfall of between 1,500 to 2,000 millimetres (59 to 79 in). It is one of three hotspots of deep convection (thunderstorms) in the tropics, the other two being over the Maritime continent and the Amazon. These three regions together drive the climate circulation of the tropics and beyond. The Congo Basin has the highest lightning strike frequency of anywhere on the planet. The high rainfall supports the second-largest rainforest on Earth, which is a globally significant carbon sink and an important component of the global carbon cycle.

Averaged across the basin, there are two major rainfall seasons in March to May and September to November.

Ecology and protection

At a global level, Congo's forests act as the planet's second lung, counterpart to the rapidly dwindling Amazon. They are a huge "carbon sink", trapping carbon that could otherwise remain carbon dioxide. The Congo Basin holds roughly 8% of the world's forest-based carbon. Despite this importance, it gets far less scientific attention than the Amazon or the tropical forests of South East Asia. If these woodlands are deforested, the carbon they trap will be released into the atmosphere. Predictions for future unabated deforestation estimate that by 2050 activities in the DRC will release roughly the same amount of carbon dioxide as the United Kingdom has emitted over the last 60 years. A 2013 study by British scientists shows that deforestation in the Congo Basin rainforest is slowing.

History

The first inhabitants of the Congo Basin area were believed to be pygmies, and at that time, the dense forests and wet climate kept the population of the region low, with the prevention of hunter-gatherer society, whose remnants of their culture survive to the present day. Eventually Bantu peoples migrated there and founded the Kingdom of Kongo.Belgium, France, and Portugal later established colonial control over the entire region by the late 19th century.

Geography

The Sahel spans 5,900 km (3,670 mi) from the Atlantic Ocean in the west to the Red Sea in the east, in a belt several hundred to a thousand kilometers (c. 600 miles) wide. It covers an area of 3,053,200 square kilometers (1,178,850 sq mi).

Representing a climatic and ecological transition zone with hot semi-desert and steppe conditions, the region borders the more humid Sudanian savannas to its south and the dry Sahara desert to the north. This ecoregion is also called the Sahelian acacia savanna in honour of its most prominent and very drought tolerant genus of tree.

The topography is mainly flat; most of the region lies between 200 and 400 meters (660 and 1,310 ft) in elevation.

History

Around 4000 BC, the climate of the Sahara and the Sahel started to become drier at an exceedingly fast pace. This climate change caused lakes and rivers to shrink significantly and caused increasing desertification. This in turn decreased the amount of land conducive to settlements and caused migrations of farming communities to the more humid climate of West Africa.

The larger Sahelian kingdoms emerged from 750 AD and founded several large cities in the Niger valley region, including Timbuktu, Gao and Djenné.

The kingdom of Alodia was a Christian Nubian Kingdom in the eastern Sahel that reached its zenith from the 9th to 12th century. It was first mentioned in 569, its capital Soba located near modern-day Khartoum.

Geography

The Libyan Desert covers an area of approximately 1,300,000 km2 (500,000 square miles), and extends approximately 1,100 km (680 miles) from east to west, and 1,000 km from north to south, in about the shape of a rectangle slanting to the south-east. Like most of the Sahara, this desert is primarily sand and hamada or stony plain.

Sand plains, dunes, ridges, and some depressions (basins) typify the endorheic region, with no rivers draining into or out of the desert. The Gilf Kebir plateau reaches an altitude of just over 1,000 m (3,300 feet), and along with the nearby massif of Jebel Uweinat is an exception to the uninterrupted territory of basement rocks covered by layers of horizontally bedded sediments, forming a massive sand plain, low plateaus, and dunes.

Climate

The Libyan Desert is said to be one of the least hospitable regions on Earth. Its climate is surprisingly variable, being hot in summer, with average daytime temperatures of 50 °C (122 °F) and above, though this drops rapidly at night. In winter, days are cool, with temperatures averaging 27 °C (81 °F), but at night this can drop below freezing, with temperatures of −9 °C (16 °F) recorded. At these times the formation of hoar frost is not uncommon, and they are known as "White Nights".

In the north, along the Mediterranean shore, cool onshore winds blow inland, while further south, hot, dry winds, known as Ghibli, blow from the interior, creating blinding sand-storms. Periodic droughts are common in the desert, often lasting several years.

History

Historically, "Libya" referred to an ill-defined area to the west of Ancient Egypt, whose boundary traditionally was the lake of Mareotis, outside Alexandria. The ancient Greeks, such as Herodotus, regarded the whole of the North African littoral, to Cape Spartel in Morocco, as "Libya". Later, the Romans organized the region the provinces of Libya Inferior and Libya Superior, which covered western Egypt and Cyrenaica. Thus the "Libyan Desert" was the desert to the south of Ancient Libya. With the organization of the Italian colony of Libya in the 20th century the term "Libyan Desert" for this region became a misnomer, and the area of desert within Egypt became known as the "Western Desert" (i.e. west of the Nile, in contradistinction to the Eastern Desert, east of the Nile).