Editing Geography of Sudan (section)

==Geographical regions==
[[File:Political Regions of Sudan, July 2010.svg|thumb|right|
{{legend|#f7931d|North Sudan}}
{{legend|#8cc63f|[[Darfur]]}}
{{legend|#800080|[[Eastern Front (Sudan)|Eastern Front, area of operations July 2006]]}}
{{legend|#FFFF00|[[Abyei]]}}
{{legend|#fb6282|[[South Kurdufan]] and [[Blue Nile (state)|Blue Nile]]}}
]]

Northern Sudan –lying between the Egyptian border and [[Sennar]]– has two distinct parts, the desert and the [[Nile Valley]].<ref name="regions">{{citation-attribution|1={{Cite encyclopedia|last=Bechtold|first=Peter K.|title=Geographic regions|editor-last=Berry|editor1-first=LaVerle|url=https://www.loc.gov/rr/frd/cs/pdf/CS_Sudan.pdf|encyclopedia=Sudan: a country study|date=2015|publisher=[[Federal Research Division]], [[Library of Congress]]|isbn=978-0-8444-0750-0|edition=5th|location=Washington, D.C.|pages=63–66}}}} Though published in 2015, this work covers events in the whole of Sudan (including present-day South Sudan) until the 2011 secession of South Sudan.</ref> To the east of the Nile is the [[Nubian Desert]] and to the west, the [[Libyan Desert]].<ref name="regions" /> Both are stony, with sandy [[dune]]s drifting over the landscape.<ref name="regions" /> There is virtually no rainfall in these deserts.<ref name="regions" /> Water in the Libyan desert is limited to a few small watering holes, such as [[Bir an Natrun]], where the water table reaches the surface to form wells that provide water for [[nomad]]s, [[Camel train|caravan]]s, and administrative patrols, although insufficient to support an [[oasis]] and inadequate to provide for a settled population.<ref name="regions" /> The Nubian Desert has no oases.<ref name="regions" /> Flowing through the desert is the Nile Valley, whose alluvial strip of habitable land is no more than two kilometers wide and whose productivity depends on the annual flood.<ref name="regions" />
[[Image:Sudan desert of east sudan 01.jpg|thumb|The desert of east Sudan|left]]
Sudan's western front encompasses the regions known as [[Darfur]] and [[Kurdufan]] that comprise 850,000 square kilometers.<ref name="regions" /> Traditionally, this has been regarded as a single regional unit despite the physical differences.<ref name="regions" /> The dominant feature throughout this immense area is the absence of perennial streams; thus, people and animals must remain within reach of permanent wells.<ref name="regions" /> Consequently, the population is sparse and unevenly distributed.<ref name="regions" /> Western Darfur is an undulating plain dominated by the volcanic massif of [[Jabal Marrah]] towering 900 meters above the Sudanic plain; the drainage from Jabal Marrah onto the plain can support a settled population and a variety of wildlife (see [[East Saharan montane xeric woodlands]]).<ref name="regions" /> Western Darfur stands in contrast to northern and eastern Darfur, which are semi-deserts with little water either from the intermittent streams known as [[wadis]] or from wells that normally go dry during the winter months.<ref name="regions" /> Northwest of Darfur and continuing into Chad lies the unusual region called the ''[[jizzu]]'', where sporadic winter rains generated from the [[Mediterranean Sea|Mediterranean]] frequently provide excellent grazing into January or even February.<ref name="regions" /> The southern region of western Sudan is known as the ''qoz'', a land of sand dunes that in the rainy season is characterized by a rolling mantle of grass and has more reliable sources of water with its bore holes and ''hafri'' (sing., ''[[hafr]]'') than does the north.<ref name="regions" /> A unique feature of western Sudan is the [[Nuba Mountains|Nuba mountain]] range of southeast Kurdufan in the center of the country, a conglomerate of isolated dome-shaped, sugarloaf hills that ascend steeply and abruptly from the great Sudanic plain.<ref name="regions" /> Many hills are isolated and extend only a few square kilometers, but there are several large hill masses with internal valleys that cut through the mountains high above the plain.<ref name="regions" />

Sudan's third distinct region is the central clay plains that stretch eastward from the Nuba Mountains to the Ethiopian border, broken only by the [[Ingessana Hills]], and from Khartoum in the north to the far reaches of southern Sudan.<ref name="regions" /> Between the [[Dindar River|Dindar]] and the [[Rahad River|Rahad]] rivers, a low ridge slopes down from the [[Ethiopian Highlands|Ethiopian highlands]] contrasting the neighboring plains as do the occasional hills.<ref name="regions" /> The central clay plains provide the backbone of Sudan's economy because of the large amounts of settlements which are there due to the available water.<ref name="regions" /> In the heartland of the central clay plains lies the ''[[Al Jazirah (state)|jazirah]]'', (literally in Arabic "peninsula") the land between the [[Blue Nile]] and the [[White Nile]] where the great [[Gezira Scheme]] was developed.<ref name="regions" /> This project grows cotton for export and has historically produced more than half of Sudan's revenue and export earnings.<ref name="regions" />

Northeast of the central clay plains lies eastern Sudan, which is divided between desert and semi-desert and includes the [[Butana]], the [[Mareb River|Qash Delta]], the [[Red Sea Hills]], and the coastal plain.<ref name="regions" /> The Butana is an undulating land between Khartoum and [[Kassala]] that provides good grazing for cattle, sheep, and goats.<ref name="regions" /> East of the Butana is a geological formation known as the Qash Delta.<ref name="regions" /> Originally a depression, it has been filled with sand and [[silt]] brought down by the flash floods of the [[Qash River]], creating a delta above the surrounding plain.<ref name="regions" /> Extending 100 kilometers north of Kassala, the whole area watered by the Qash is a rich grassland with bountiful cultivation long after the river has spent its waters on the surface of its delta.<ref name="regions" /> Trees and bushes provide grazing for the camels from the north, and the rich moist soil provides an abundance of food crops and cotton.<ref name="regions" />

Northward beyond the Qash lie the Red Sea Hills.<ref name="regions" /> Dry, bleak, and cooler than the surrounding land, particularly in the heat of the Sudanese summer, they stretch northward into Egypt, a jumbled mass of hills where life is hard and unpredictable for the [[Beja people|Beja]] inhabitants.<ref name="regions" /> Below the hills sprawls the coastal plain of the Red Sea, varying in width from about fifty-six kilometers in the south near [[Tawkar]] to about twenty-four kilometers near the Egyptian border.<ref name="regions" /> The coastal plain is dry and barren.<ref name="regions" /> It consists of rocks, and the seaward side is thick with coral reefs.<ref name="regions" />