{{Infobox river | name = Wadi Howar | native_name = <!-- {{native name|<tag>|<name>}} or {{native name list |tag1=<tag>|name1=<name> |tag2=<tag>|name2=<name> ... }} --> | name_other = | name_etymology = | nickname = | image = Map of Sudan (New).jpg | image_size = | image_caption = Map of Sudan (after 2011) | image_alt =

| mouth = [[Nile]] | mouth_coordinates = {{Coord|18|11|56|N|30|44|26|E|region:SD|display=inline,title}} }} '''Wadi Howar''' ('''Wadi Howa''' or '''Yellow Nile''') is a [[wadi]] in [[Sudan]] and [[Chad]].

== Geography == Originating in the [[Ennedi Region]] of [[Chad]] ''Wadi Howar'' runs through the Sudanese states of [[North Darfur]] and [[Northern state, Sudan|Northern]] to join the Nile north of the [[Nile#In Sudan|great bend]] opposite [[Old Dongola]]. Stretching over 1100&nbsp;km<ref name=ises>{{cite book |first=Intisar Soghayroun Elzein |last=Soghayroun |title=Trade and Wadi System(s) in Muslim Sudan |location=Kampala |year=2010 |hdl=1956/3994 |isbn=978-9970-25-005-9 }}</ref>{{rp|25}} in west–east direction across the southern fringes of the [[Libyan Desert]], it ordinarily receives 25&nbsp;mm of rainfall per year.<ref name=kp>{{cite journal |authorlink=Stefan Kröpelin |last1=Kröpelin |first1=Stefan |last2=Pachur |first2=Hans-Joachim |year=1987 |title=Wadi Howar: Paleoclimatic Evidence from an Extinct River System in the Southeastern Sahara |journal=[[Science (journal)|Science]] |volume=237 |issue=4812 |pages=298–300 |doi=10.1126/science.237.4812.298 |pmid=17772057 |bibcode=1987Sci...237..298P |s2cid=3894313 }}</ref>

== Holocene period == [[File:Nile Map Sudan.png|thumb|280px|Map of Nile tributaries in modern Sudan]] ''Wadi Howar'' is the remnant of the ancient [[Nile#Yellow Nile|''Yellow Nile'']], a tributary of the [[Nile]] during the [[African humid period]] from about 9500 to 4500 years ago. At that time, [[savanna]] fauna and cattle [[herder]]s occupied this region and the southern edge of the [[Sahara]] was some {{convert|500|km}} further north than it is today.<ref name=kp/> When the Sahara underwent [[desertification]] between 6000 and 4000 years ago, the [[wadi]] first became a chain of freshwater lakes and marshes, as shown by [[Ptolemy's world map]], then it became extinct about 2000 years ago.<ref name=ises/>{{rp|28}}

== Archaeology == Abundant prehistoric sites certify ''Wadi Howar'' as a once ecologically favoured area of settlement and a communication route between the inner regions of Africa and the Nile Valley.<ref name=ises/>{{rp|31}} The hitherto most thoroughly investigated archaeological site in the wadi is [[Gala Abu Ahmed]].

== See also == * [[African humid period]] * [[Lake Ptolemy]]

== References == {{Reflist}}

{{Authority control}}

[[Category:Wadis of Sudan|Howar]] [[Category:Nile]] [[Category:Rivers of Sudan]] [[Category:Rivers of Chad]] [[Category:International rivers of Africa]] [[Category:Chad–Sudan border]] [[Category:North Darfur]]