Editing Geography of Namibia (section)

==Weather and climate==
[[File:Koppen-Geiger_Map_v2_NAM_1991–2020.svg|thumb|350px|Köppen climate classification map of Namibia]] [[Namibia]] has more than 300 days of sunshine per year. It is situated at the southern edge of the tropics; the [[Tropic of Capricorn]] cuts the country about in half. The winter (June–August) is generally dry, both rainy seasons occur in summer, the small rainy season between September and November, and the big one between February and April.<ref>{{Cite web
 |publisher=Real Namibia 
 |title=The Rainy Season 
 |url=http://www.realnamibia.com/rn_028rainyseason.htm
 |archive-url=https://archive.today/20121209093846/http://www.realnamibia.com/rn_028rainyseason.htm
 |url-status=dead
 |archive-date=9 December 2012
 |access-date=28 July 2010 
}}</ref> Humidity is low, and average rainfall varies from almost zero in the [[Skeleton Coast|coastal desert]] to more than {{convert|600|mm|in|0|disp=or}} in the [[Caprivi Strip]]. Rainfall is however highly variable, and droughts are common.<ref name="EBClimate">{{cite encyclopedia
|title=Namibia
|url=http://www.britannica.com/EBchecked/topic/402283/Namibia/43996
|encyclopedia=[[Encyclopædia Britannica]]
|access-date=28 July 2010}}</ref> A bad rainy season occurred in the summer of 2006/07.<ref name="Olszewski1">{{Cite news
|last=Olszewski
|first=John
|newspaper=[[Namibia Economist]]
|title=Climate change forces us to recognise new normals
|url=http://www.economist.com.na/index.php?option=com_content&view=article&catid=531:weather&id=14308:climate-change-forces-us-to-recognise-new-normals&Itemid=54
|date=28 May 2009
}}</ref> Very low rainfall was recorded in 2019.<ref>{{Cite web|last=Namibian|first=The|title=State of drought emergency extended|url=https://www.namibian.com.na/index.php?page=archive-read&id=193796|access-date=2020-11-24|website=The Namibian|language=en|archive-date=10 March 2021|archive-url=https://web.archive.org/web/20210310104544/https://www.namibian.com.na/index.php?page=archive-read&id=193796|url-status=dead}}</ref> Due to the dry winters snowfall constitutes a very rare occurrence and prompts media coverage whenever it happens. The {{As of|June 2011|alt=last}} snow was reported at [[Spreetshoogte Pass]] in the [[Namib-Naukluft Park]] in June 2011.<ref>{{cite news
 |url         = http://www.namibian.com.na/news/full-story/archive/2011/june/article/snow-sets-another-record/
 |title       = Snow sets another record
 |last        = Smith
 |first       = Jana-Mari
 |date        = 9 June 2011
 |newspaper   = [[The Namibian]]
 |url-status     = dead
 |archive-url  = https://web.archive.org/web/20120422174131/http://www.namibian.com.na/news/full-story/archive/2011/june/article/snow-sets-another-record
 |archive-date = 22 April 2012
}}</ref>

Weather and climate in the coastal area are dominated by the cold, north-flowing [[Benguela Current]] of the Atlantic Ocean which accounts for very low [[Precipitation (meteorology)|precipitation]] totalling {{convert|50|mm|in|0|disp=or}} per year or less, frequent dense fog, and overall lower temperatures than in the rest of the country.<ref name="EBClimate"/> In winter, occasionally a condition known as ''[[Berg wind]]'' or ''Oosweer'' ([[Afrikaans]]: East weather) occurs, a hot dry wind blowing from the inland to the coast. As the area behind the coast is a desert, these winds can develop into sand storms with sand deposits in the Atlantic Ocean visible on satellite images.<ref name="Olszewski2">{{Cite news
|last=Olszewski
|first=John
|newspaper=Namibia Economist
|title=Understanding Weather – not predicting it
|url=http://www.economist.com.na/index.php?option=com_content&view=category&layout=blog&id=575&Itemid=54&limitstart=5
|date=25 June 2010
}}</ref>

The Central Plateau and Kalahari areas have wide [[Diurnal temperature variation|diurnal]] temperature ranges of up to {{convert|30|C-change|F-change|1|disp=or}}.<ref name="EBClimate"/>

=== Examples ===

{{Weather box
|location = Windhoek ({{convert|1728|m|ft|0|disp=or}}), Namibia
|metric first = yes
|single line = yes
|width = auto
|collapsed = yes

|Jan record high C = 36.0
|Feb record high C = 35.8
|Mar record high C = 34.9
|Apr record high C = 31.3
|May record high C = 31.8
|Jun record high C = 26.1
|Jul record high C = 25.7
|Aug record high C = 30.0
|Sep record high C = 33.2
|Oct record high C = 35.1
|Nov record high C = 36.5
|Dec record high C = 36.6

|Jan high C = 30.0
|Feb high C = 28.6
|Mar high C = 27.2
|Apr high C = 25.6
|May high C = 22.7
|Jun high C = 20.2
|Jul high C = 20.5
|Aug high C = 23.4
|Sep high C = 26.5
|Oct high C = 29.1
|Nov high C = 29.6
|Dec high C = 30.7
|year high C = 26.1

|Jan mean C = 23.3
|Feb mean C = 22.1
|Mar mean C = 21.0
|Apr mean C = 18.9
|May mean C = 15.8
|Jun mean C = 13.2
|Jul mean C = 13.1
|Aug mean C = 15.8
|Sep mean C = 19.3
|Oct mean C = 21.7
|Nov mean C = 22.5
|Dec mean C = 23.5
|year mean C = 19.1

|Jan low C = 17.2
|Feb low C = 16.5
|Mar low C = 15.4
|Apr low C = 12.8
|May low C = 9.2
|Jun low C = 6.7
|Jul low C = 6.3
|Aug low C = 8.6
|Sep low C = 11.9
|Oct low C = 14.6
|Nov low C = 15.6
|Dec low C = 16.9
|year low C = 12.7

|Jan record low C = 7.5
|Feb record low C = 6.8
|Mar record low C = 3.7
|Apr record low C = 2.4
|May record low C = -1.6
|Jun record low C = -2.8
|Jul record low C = -2.6
|Aug record low C = -3.9
|Sep record low C = -1.1
|Oct record low C = 1.6
|Nov record low C = 0.4
|Dec record low C = 3.3

|Jan precipitation mm = 78.1
|Feb precipitation mm = 80.3
|Mar precipitation mm = 78.7
|Apr precipitation mm = 37.7
|May precipitation mm = 6.6
|Jun precipitation mm = 1.2
|Jul precipitation mm = 0.7
|Aug precipitation mm = 0.9
|Sep precipitation mm = 2.8
|Oct precipitation mm = 11.8
|Nov precipitation mm = 26.9
|Dec precipitation mm = 41.7

|unit precipitation days = 0.1 mm
|Jan precipitation days = 11.1
|Feb precipitation days = 10.7
|Mar precipitation days = 10.5
|Apr precipitation days = 5.5
|May precipitation days = 1.9
|Jun precipitation days = 0.7
|Jul precipitation days = 0.5
|Aug precipitation days = 0.3
|Sep precipitation days = 0.9
|Oct precipitation days = 2.8
|Nov precipitation days = 5.3
|Dec precipitation days = 7.5

|Jan humidity = 42
|Feb humidity = 56
|Mar humidity = 51
|Apr humidity = 44
|May humidity = 37
|Jun humidity = 32
|Jul humidity = 27
|Aug humidity = 19
|Sep humidity = 17
|Oct humidity = 22
|Nov humidity = 30
|Dec humidity = 34

|Jan sun = 288
|Feb sun = 254
|Mar sun = 282
|Apr sun = 273
|May sun = 310
|Jun sun = 309
|Jul sun = 326
|Aug sun = 341
|Sep sun = 321
|Oct sun = 319
|Nov sun = 297
|Dec sun = 285
| source 1 = [[Deutscher Wetterdienst]]<ref>{{cite web
| url = http://www.dwd.de/DWD/klima/beratung/ak/ak_681100_kt.pdf
| title = Klimatafel von Windhuk (Windhoek) / Namibia
| publisher = Federal Ministry of Transport and Digital Infrastructure
| access-date = 2 November 2016
| archive-url = https://web.archive.org/web/20190512035512/https://www.dwd.de/DWD/klima/beratung/ak/ak_681100_kt.pdf
| archive-date = 12 May 2019
| url-status = dead
}}</ref>
| source 2 = [[Danish Meteorological Institute]] (sun only)<ref>
{{cite web
 |url         = http://www.dmi.dk/dmi/tr01-17.pdf
 |title       = Stationsnummer 68110
 |publisher   = Ministry of Energy, Utilities and Climate
 |access-date  = 2 November 2016
 |url-status     = deviated
 |archive-url  = https://web.archive.org/web/20130116071752/http://www.dmi.dk/dmi/tr01-17.pdf
 |archive-date = 16 January 2013
}}
</ref>
}}

{{Weather box
|location = Pelican Point, Walvis Bay ({{convert|7|m|ft|0|disp=or}}), Namibia (1958–1984)
|metric first = yes
|single line = yes
|width = auto 
|collapsed = yes

|Jan record high C = 25.3
|Feb record high C = 26.4
|Mar record high C = 34.5
|Apr record high C = 35.0
|May record high C = 36.0
|Jun record high C = 32.5
|Jul record high C = 32.9
|Aug record high C = 33.4
|Sep record high C = 31.3
|Oct record high C = 27.5
|Nov record high C = 28.3
|Dec record high C = 25.5

|Jan high C = 20.0
|Feb high C = 20.3
|Mar high C = 19.6
|Apr high C = 18.6
|May high C = 19.0
|Jun high C = 18.8
|Jul high C = 17.8
|Aug high C = 16.4
|Sep high C = 15.8
|Oct high C = 16.6
|Nov high C = 17.7
|Dec high C = 19.0
|year high C = 18.3

|Jan mean C = 17.6
|Feb mean C = 17.9
|Mar mean C = 17.2
|Apr mean C = 15.7
|May mean C = 15.6
|Jun mean C = 15.2
|Jul mean C = 14.1
|Aug mean C = 13.2
|Sep mean C = 13.2
|Oct mean C = 14.0
|Nov mean C = 15.3
|Dec mean C = 16.6
|year mean C = 15.5

|Jan low C = 15.2
|Feb low C = 15.5
|Mar low C = 14.7
|Apr low C = 12.9
|May low C = 12.1
|Jun low C = 11.4
|Jul low C = 10.3
|Aug low C = 10.1
|Sep low C = 10.7
|Oct low C = 11.5
|Nov low C = 12.9
|Dec low C = 14.2
|year low C = 12.6

|Jan record low C = 10.5
|Feb record low C = 9.2
|Mar record low C = 10.5
|Apr record low C = 8.5
|May record low C = 7.0
|Jun record low C = 5.0
|Jul record low C = 3.4
|Aug record low C = 4.4
|Sep record low C = 6.1
|Oct record low C = 5.0
|Nov record low C = 8.5
|Dec record low C = 9.6

|Jan precipitation mm = 1.0
|Feb precipitation mm = 2.0
|Mar precipitation mm = 5.0
|Apr precipitation mm = 1.0
|May precipitation mm = 1.0
|Jun precipitation mm = 2.0
|Jul precipitation mm = 0.0
|Aug precipitation mm = 0.2
|Sep precipitation mm = 0.1
|Oct precipitation mm = 0.1
|Nov precipitation mm = 0.7
|Dec precipitation mm = 0.1

|unit precipitation days = 0.1 mm
|Jan precipitation days = 0.6
|Feb precipitation days = 0.8
|Mar precipitation days = 1.1
|Apr precipitation days = 0.5
|May precipitation days = 0.4
|Jun precipitation days = 0.5
|Jul precipitation days = 0.0
|Aug precipitation days = 0.4
|Sep precipitation days = 0.5
|Oct precipitation days = 0.4
|Nov precipitation days = 0.6
|Dec precipitation days = 0.4

|Jan humidity = 87
|Feb humidity = 87
|Mar humidity = 89
|Apr humidity = 89
|May humidity = 86
|Jun humidity = 81
|Jul humidity = 82
|Aug humidity = 86
|Sep humidity = 89
|Oct humidity = 88
|Nov humidity = 88
|Dec humidity = 88

|Jan sun = 232
|Feb sun = 189
|Mar sun = 211
|Apr sun = 237
|May sun = 251
|Jun sun = 231
|Jul sun = 236
|Aug sun = 220
|Sep sun = 189
|Oct sun = 226
|Nov sun = 210
|Dec sun = 214
| source 1 = [[Deutscher Wetterdienst]]<ref>
{{cite web
| url = http://www.dwd.de/DWD/klima/beratung/ak/ak_681040_kt.pdf
| title = Klimatafel von Pelican Point / Walfisch-Bucht / Namibia
| publisher = Federal Ministry of Transport and Digital Infrastructure
| access-date = 4 November 2016}}
</ref>
| source 2 = [[Danish Meteorological Institute]]<ref>
{{cite web
 |url         = http://www.dmi.dk/dmi/tr01-17.pdf
 |title       = STATIONSNUMMER 68104
 |publisher   = Ministry of Energy, Utilities and Climate
 |access-date  = 4 November 2016
 |url-status     = deviated
 |archive-url  = https://web.archive.org/web/20130116071752/http://www.dmi.dk/dmi/tr01-17.pdf
 |archive-date = 16 January 2013
}}
</ref>
}}

{{Weather box
|location = Lüderitz
|metric first = Yes
|single line = Yes
|width = auto
|collapsed = yes
|Jan record high C = 32.5
|Feb record high C = 30.0
|Mar record high C = 34.1
|Apr record high C = 36.5
|May record high C = 33.0
|Jun record high C = 31.6
|Jul record high C = 30.7
|Aug record high C = 33.0
|Sep record high C = 35.1
|Oct record high C = 35.0
|Nov record high C = 37.5
|Dec record high C = 30.6
|year record high C = 37.5
|Jan high C = 21.4
|Feb high C = 21.3
|Mar high C = 21.1
|Apr high C = 19.9
|May high C = 19.2
|Jun high C = 19.0
|Jul high C = 17.9
|Aug high C = 17.2
|Sep high C = 17.3
|Oct high C = 18.0
|Nov high C = 19.2
|Dec high C = 20.5
|year high C = 19.3
|Jan mean C = 17.7
|Feb mean C = 17.8
|Mar mean C = 17.4
|Apr mean C = 16.3
|May mean C = 15.5
|Jun mean C = 15.1
|Jul mean C = 14.1
|Aug mean C = 13.7
|Sep mean C = 13.9
|Oct mean C = 14.7
|Nov mean C = 15.8
|Dec mean C = 17.0
|year mean C = 15.7
|Jan low C = 14.0
|Feb low C = 14.3
|Mar low C = 13.8
|Apr low C = 12.6
|May low C = 11.7
|Jun low C = 11.2
|Jul low C = 10.4
|Aug low C = 10.2
|Sep low C = 10.5
|Oct low C = 11.4
|Nov low C = 12.3
|Dec low C = 13.5
|year low C = 12.1
|Jan record low C = 5.5
|Feb record low C = 5.0
|Mar record low C = 6.0
|Apr record low C = 5.5
|May record low C = 3.3
|Jun record low C = 0.2
|Jul record low C = 3.0
|Aug record low C = 4.8
|Sep record low C = 3.4
|Oct record low C = 3.4
|Nov record low C = 4.9
|Dec record low C = 3.9
|year record low C = 0.2
|precipitation colour = green
|Jan precipitation mm = 0
|Feb precipitation mm = 1
|Mar precipitation mm = 2
|Apr precipitation mm = 2
|May precipitation mm = 3
|Jun precipitation mm = 3
|Jul precipitation mm = 1
|Aug precipitation mm = 2
|Sep precipitation mm = 1
|Oct precipitation mm = 0
|Nov precipitation mm = 0
|Dec precipitation mm = 0
|year precipitation mm = 17
|unit precipitation days = 0.1 mm
|Jan precipitation days = 1.0
|Feb precipitation days = 1.0
|Mar precipitation days = 1.0
|Apr precipitation days = 0.9
|May precipitation days = 1.4
|Jun precipitation days = 1.4
|Jul precipitation days = 1.0
|Aug precipitation days = 0.7
|Sep precipitation days = 0.5
|Oct precipitation days = 0.5
|Nov precipitation days = 0.5
|Dec precipitation days = 0.7
|year precipitation days = 10.6
|Jan humidity = 82
|Feb humidity = 81
|Mar humidity = 82
|Apr humidity = 80
|May humidity = 79
|Jun humidity = 72
|Jul humidity = 74
|Aug humidity = 78
|Sep humidity = 80
|Oct humidity = 80
|Nov humidity = 80
|Dec humidity = 80
|year humidity = 79
|Jan sun = 198.4
|Feb sun = 203.4
|Mar sun = 257.3
|Apr sun = 216.0
|May sun = 213.9
|Jun sun = 144.0
|Jul sun = 170.5
|Aug sun = 201.5
|Sep sun = 216.0
|Oct sun = 201.5
|Nov sun = 189.0
|Dec sun = 176.7
|year sun =
|Jand sun = 6.4
|Febd sun = 7.2
|Mard sun = 8.3
|Aprd sun = 7.2
|Mayd sun = 6.9
|Jund sun = 4.8
|Juld sun = 5.5
|Augd sun = 6.5
|Sepd sun = 7.2
|Octd sun = 6.5
|Novd sun = 6.3
|Decd sun = 5.7
|yeard sun = 6.5
|source 1 = [[Deutscher Wetterdienst]]<ref name = LüderitzDWD>
{{cite web
| url = http://www.dwd.de/DWD/klima/beratung/ak/ak_683000_kt.pdf
| title = Klimatafel von Lüderitz-Diaz Point (Leuchtturm) / Namibia
| work = Baseline climate means (1961–1990) from stations all over the world
| publisher = Deutscher Wetterdienst
| language = de
| access-date = 29 March 2016}}</ref>
|date=August 2011
}}

{{Weather box
|location = Keetmanshoop 
|metric first = Y
|single line = Y
|width = auto
|collapsed = yes
|Jan high C = 34.8
|Feb high C = 34.0
|Mar high C = 32.2
|Apr high C = 28.8
|May high C = 25.0
|Jun high C = 21.7
|Jul high C = 21.3
|Aug high C = 23.5
|Sep high C = 27.2
|Oct high C = 30.1
|Nov high C = 32.4
|Dec high C = 34.5
|year high C = 28.8
|Jan low C = 19.0
|Feb low C = 19.3
|Mar low C = 17.8
|Apr low C = 14.4
|May low C = 10.4
|Jun low C = 7.0
|Jul low C = 6.4
|Aug low C = 7.5
|Sep low C = 10.7
|Oct low C = 13.7
|Nov low C = 15.7
|Dec low C = 17.6
|year low C = 13.3
|Jan precipitation mm = 24
|Feb precipitation mm = 42
|Mar precipitation mm = 36
|Apr precipitation mm = 15
|May precipitation mm = 5
|Jun precipitation mm = 2
|Jul precipitation mm = 1
|Aug precipitation mm = 1
|Sep precipitation mm = 3
|Oct precipitation mm = 6
|Nov precipitation mm = 11
|Dec precipitation mm = 13
|Jan humidity = 28
|Feb humidity = 36
|Mar humidity = 40
|Apr humidity = 40
|May humidity = 38
|Jun humidity = 39
|Jul humidity = 36
|Aug humidity = 31
|Sep humidity = 27
|Oct humidity = 24
|Nov humidity = 24
|Dec humidity = 25
|Jan sun = 353
|Feb sun = 300
|Mar sun = 312
|Apr sun = 306
|May sun = 304
|Jun sun = 287
|Jul sun = 305
|Aug sun = 323
|Sep sun = 319
|Oct sun = 343
|Nov sun = 348
|Dec sun = 370
|Jan percentsun= 84
|Feb percentsun= 82
|Mar percentsun= 82
|Apr percentsun= 89
|May percentsun= 91
|Jun percentsun= 91
|Jul percentsun= 93
|Aug percentsun= 93
|Sep percentsun= 89
|Oct percentsun= 87
|Nov percentsun= 86
|Dec percentsun= 86
|year percentsun= 
|source 1 = [http://www.meteona.com/attachments/035_Namibia_Long-term_Climate_Statistics_for_Specified_Places%5B1%5D.pdf Tabulation of Climate Statistics for Selected Stations in Namibia]
}}

{{Weather box
|location = Katima Mulilo, Namibia
|metric first = Yes
|single line = Yes
|width = auto
|collapsed = yes
|Jan high C = 31.3
|Feb high C = 30.5
|Mar high C = 29.8
|Apr high C = 29.1
|May high C = 27.4
|Jun high C = 24.5
|Jul high C = 25.0
|Aug high C = 29.1
|Sep high C = 33.8
|Oct high C = 33.0
|Nov high C = 30.3
|Dec high C = 29.8
|year high C = 29.5
|Jan low C = 19.1
|Feb low C = 19.1
|Mar low C = 18.7
|Apr low C = 14.6
|May low C = 10.2
|Jun low C = 6.1
|Jul low C = 4.6
|Aug low C = 8.3
|Sep low C = 14.1
|Oct low C = 17.8
|Nov low C = 19.3
|Dec low C = 18.8
|year low C = 14.2
|Jan humidity = 68
|Feb humidity = 66
|Mar humidity = 70
|Apr humidity = 61
|May humidity = 53
|Jun humidity = 53
|Jul humidity = 62
|Aug humidity = 50
|Sep humidity = 42
|Oct humidity = 46
|Nov humidity = 49
|Dec humidity = 57
|year humidity = 56.4
|Jan precipitation mm = 169.4
|Feb precipitation mm = 160.6
|Mar precipitation mm = 88.7
|Apr precipitation mm = 17.7
|May precipitation mm = 1.9
|Jun precipitation mm = 0.5
|Jul precipitation mm = 0
|Aug precipitation mm = 0.2
|Sep precipitation mm = 2.6
|Oct precipitation mm = 18.8
|Nov precipitation mm = 69.7
|Dec precipitation mm = 151.8
|year precipitation mm = 681.9
|source = Ministry of Works and Transport (Meteorological Service Division)
{{cite web
|url =http://www.meteona.com/attachments/035_Namibia_Long-term_Climate_Statistics_for_Specified_Places[1].pdf |title =Ministry of Works & Transport: Tabulation of Climate Statistics for Selected Stations in Namibia 
|year=2012}}
|date=March 2012}}

===Water sources===
{{Main|Water supply and sanitation in Namibia}}
Namibia is the driest country in [[sub-Saharan Africa]] and depends largely on groundwater. With an average rainfall of about {{cvt|350|mm|in|0}} per annum, the highest rainfall occurs in the [[Caprivi Strip|Caprivi]] in the northeast (about {{cvt|600|mm|in|0}} per annum) and decreases in a westerly and southwesterly direction to as little as {{cvt|50|mm|in|0}} and less per annum at the coast. The only perennial rivers are found on the national borders with [[South Africa]], [[Angola]], [[Zambia]], and the short border with [[Botswana]] in the [[Caprivi Strip|Caprivi]]. In the interior of the country, surface water is available only in the summer months when rivers are in flood after exceptional rainfalls. Otherwise, surface water is restricted to a few large storage dams retaining and damming up these seasonal floods and their runoff. Where people do not live near perennial rivers or make use of storage dams, they are dependent on groundwater. Even isolated communities and those economic activities located far from good surface water sources, such as mining, agriculture, and tourism, can be supplied from groundwater over nearly 80% of the country.<ref>{{cite web |url=http://www.iwrm-namibia.info.na/iwrm/fundaments-in-iwrm/groundwater-in-namibia/index.php |title=Groundwater in Namibia |website=Integrated Water Resource Management |url-status=dead |archive-url=https://web.archive.org/web/20160729155617/http://www.iwrm-namibia.info.na/iwrm/fundaments-in-iwrm/groundwater-in-namibia/index.php |archive-date=29 July 2016 }}</ref> The longest river in Namibia is the [[Fish River (Namibia)|Fish River]] with a length of {{convert|650|km|mi|abbr=on}}.

More than 120,000 [[borehole]]s have been drilled in Namibia over the past century. One-third of these boreholes have been drilled dry.<ref>{{cite book |title=Groundwater in Namibia |url=http://www.namhydro.com/downloads.html |editor1=Greg Christelis |name-list-style=amp |editor2=Wilhelm Struckmeier |via=Namibian Hydrogeological Association |year=2001 |isbn=978-0-86976-571-5 |access-date=2018-07-10 |archive-url=https://web.archive.org/web/20150404091336/http://namhydro.com/downloads.html |archive-date=4 April 2015 |url-status=dead }}</ref> An [[aquifer]] called "Ohangwena II", located on both sides of the Angola-Namibia border, was discovered in 2012. This aquifer has been estimated to be capable of supplying the 800,000 people in the North for 400 years, at the current (2018) rate of consumption.<ref name=aqui>{{cite web|last=McGrath |first=Matt |url=https://www.bbc.co.uk/news/science-environment-18875385 |title=Vast aquifer found in Namibia could last for centuries |publisher=BBC World |date=20 July 2012 |access-date=10 September 2013}}</ref> Experts estimate that Namibia has {{convert|7720|km3|cumi|abbr=on}} of underground water.<ref name=afr>{{cite web|last=McGrath |first=Matt |url=https://www.bbc.co.uk/news/science-environment-17775211 |title='Huge' water resource exists under Africa |publisher=BBC World Service |date=20 April 2012 |access-date=10 September 2013}}</ref><ref name=aqmap>{{cite journal|vauthors=MacDonald AM, Bonsor HC, Dochartaigh BÉ, Taylor RG |doi=10.1088/1748-9326/7/2/024009|title=Quantitative maps of groundwater resources in Africa|journal=Environ. Res. Lett. |volume=7 |page=024009|year=2012|issue=2|bibcode=2012ERL.....7b4009M|citeseerx=10.1.1.693.4081|s2cid=154336728 }}</ref>

''Efundja'', the annual flooding of the northern parts of the country, often causes not only damage to infrastructure but loss of life.<ref>{{cite news
|url=http://www.unmultimedia.org/radio/english/2011/04/debilitating-floods-hit-northern-and-central-namibia/
|title=Debilitating floods hit northern and central Namibia
|last=Adams
|first=Gerry
|date=15 April 2011
|publisher=[[United Nations Radio]]
|access-date=23 April 2012
|archive-date=20 December 2016
|archive-url=https://web.archive.org/web/20161220185613/http://www.unmultimedia.org/radio/english/2011/04/debilitating-floods-hit-northern-and-central-namibia/
|url-status=dead
}}</ref> The rains that cause these floods originate in Angola, flow into Namibia's [[Cuvelai basin]], and fill the ''Oshanas'' ([[Oshiwambo]]: flood plains) there. The worst floods {{As of|2012|alt=so far}} occurred in March 2011 and displaced 21,000 people.<ref>{{cite news
|url=http://www.namibian.com.na/index.php?id=28&tx_ttnews%5Btt_news%5D=79689&no_cache=1
|title=Heaviest floods ever in Namibia
|last=van den Bosch
|first=Servaas
|date=29 March 2011
|work=[[The Namibian]]}}</ref>