Mountain Ranges, Deserts and Landforms of Sudan

Geography

The Sahara covers large parts of Algeria, Chad, Egypt, Libya, Mali, Mauritania, Niger, Western Sahara and Sudan, and parts of southern Morocco and Tunisia. It covers 9 million square kilometres (3,500,000 sq mi), 31% of the African continent. If all areas with a mean annual precipitation of less than 250 mm (9.8 in) were included, the Sahara would be 11 million square kilometres (4,200,000 sq mi). It is one of three distinct physiographic provinces of the African massive physiographic division. The Sahara is so large and bright that, in theory, it could be detected from other stars as a surface feature of Earth, with near-current technology.

Climate

The Sahara is the world's largest hot desert. It is located in the horse latitudes under the subtropical ridge, a significant belt of semi-permanent subtropical warm-core high pressure where the air from the upper troposphere usually descends, warming and drying the lower troposphere and preventing cloud formation.

The permanent absence of clouds allows unhindered light and thermal radiation. The stability of the atmosphere above the desert prevents any convective overturning, thus making rainfall virtually non-existent. As a consequence, the weather tends to be sunny, dry and stable with a minimal chance of rainfall. Subsiding, diverging, dry air masses associated with subtropical high-pressure systems are extremely unfavorable for the development of convectional showers.

History

Scientists have identified more than 230 humid periods in North Africa over the past eight million years, recurring at intervals of approximately 21,000 years.

A modern laboratory examination of the Uan Muhuggiag child mummy and Tin Hanakaten child have suggested that the Central Saharan peoples from the Epipaleolithic, Mesolithic, and Pastoral periods possessed dark skin complexions. The creators of the Round Head rock art possessed dark skin.

A 2025 study sequenced individuals from Takarkori (7,000 YBP) and discovered that most of their ancestry was from an unknown ancestral North African lineage, related to the African admixture component found in Iberomaurusians.

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 mountains are located in the center of the Darfur region of Sudan on the border of the states of South Darfur and Central Darfur, with a smaller part of the range in the state of North Darfur. The highest point is Deriba Caldera. The upper reaches of the massif is a small area of temperate climate with high rainfall and permanent springs of water amidst the dry savanna and scrub of the Sahel below.

Apart from the Aïr Mountains in Niger which are on the border of the Sahara proper, the Marrah Mountains are the only major mountain range in the otherwise flat Sahel, rising up to 2,600 metres (8,500 ft) above the plain, but are relatively unknown owing to lack of development and political conflict in the region.

The last eruption occurred around 1500 BC.

History

The Jebel Marra inhibited the spread of Arabisation from east to west, and were a place of refuge for sultans in precolonial times.

From 1984 to 1994, the Jebel Marra Rural Development Project established privately owned and community forests. The project developed nurseries, supplied seedlings and encouraged farmers to plant and manage trees on their own land. Afforestation on private land began in 1984, and some plantations had reached production by 1992, providing income for farmers. The programme relied heavily on the exotic species Eucalyptus citriodora, which farmers favoured for its rapid growth and strong market demand. After the project ended, extension services became very limited, but community forestry continued in the area.

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).

Geography

Between 100 and 35 million years ago the area that is now the Eastern Desert was underwater, covered by the Tethys Ocean. During the Oligocene period, around 34 million years ago, the land began to tilt and the coastline was pushed back to the north and west. Concurrently, the basement complex to the east was uplifted, forming the mountain range of the Desert. In this same sequence of land movements, a rift which is now the Red Sea was opened up.

The mountain range of the Eastern Desert runs between 80 and 137 kilometres (50 and 85 mi) inland from and parallel to the Red Sea Coast. It has peaks around 1,500 metres (4,900 ft) above sea level. The southern mountains are predominantly composed of igneous rock while the mountains to the north are composed of limestone.

Climate

The Eastern Desert has a semi-arid/arid/hyper-arid climate. On average, the region usually receives less than 25 millimetres (0.98 in) of rainfall per year in infrequent patterns. Most of the rainfall occurs during the winter months around the mountains. The mountains can create a rain shadow for the rest of the Desert, contributing to the arid environment.

Average temperatures are between 14 and 21 °C (57 and 70 °F) in winter (November–March) and 23.1 and 23.1 °C (73.6 and 73.6 °F) in summer (May–September). The weather is typically sunny; however, sandstorms can occur, usually between March and June. The storms (khamsins) are caused by tropical air moving up from Sudan, accompanied by strong winds and higher temperatures.

History

The earliest signs of humans in the desert was found in the form of flint tools from 250,000 BC.

Around 25,000 BC, the land underwent significant climatic change which transformed the grassy plains into desert. This made the land much less habitable, driving nomads which had inhabited what is now the Eastern Desert towards the Nile River.

Trade routes from the Nile to the Red Sea were established through the Desert. Notably, there was a route between the Nile River and Mersa Gawasis, an ancient Egyptian port. There were also many mines and quarries along this route. Boats were carried in pieces across the desert through the wadis and then set up once they reached the port to embark on expeditions.

History

The region was once occupied by the Kingdom of Kush. An indigenous Meroitic-speaking community lived in the Gezira. The area was at the southern end of Nubia and little is known about its ancient history and only limited archaeological work has been conducted in this area. It was part of the kingdom of Alodia for several centuries, and with that state's collapse in the early sixteenth century, it became the centre of the Funj Sultanate.It is the native region of the Abdallabi tribe who were formerly arabized Anaj, the Nubian Nobility of the kingdom of Alodia who also extended into Sennar.

Katfia in Gezira was the place where the Wad Habuba Revolt took place in April 1908. The Gezira Scheme was a program launched in 1925 to foster cotton farming.