Okavango Delta
{{Short description|River delta in Botswana}}
{{Use dmy dates|date=September 2015}}
{{Infobox UNESCO World Heritage Site
| WHS = Okavango Delta
| Image = Okavango Delta map.png
| Caption = Map of the delta with basin boundary as dashed line
| Location = Botswana
| Criteria = Natural: vii, ix, x
| ID = 1432
| Year = 2014
| Area = 2,023,590 ha
| Buffer_zone = 2,286,630 ha
| Coordinates = {{Coord|19|24|S|22|54|E|display=inline,title}}
| locmapin = Botswana
| embedded = {{Designation list
|embed = yes
|designation1 = Ramsar
|designation1_offname = Okavango Delta System
|designation1_date = 12 September 1996
|designation1_number = 879{{Cite web |title=Okavango Delta System |website=Ramsar Sites Information Service |url=https://rsis.ramsar.org/ris/879 |access-date=25 April 2018 |archive-date=26 July 2018 |archive-url=https://web.archive.org/web/20180726234011/https://rsis.ramsar.org/ris/879 |url-status=live }}}}
}}
File:DeltaOkawango.jpg) of Okavango Delta, with national borders added]]
File:Vista aérea del delta del Okavango, Botsuana, 2018-08-01, DD 32.jpg
The Okavango Delta{{Cite book |last=Ross |first=Karen |url=https://www.worldcat.org/oclc/17978845 |title=Okavango, jewel of the Kalahari |date=1987 |publisher=BBC Books |isbn=0-563-20545-8 |location=London |oclc=17978845}} (or Okavango Grassland; formerly spelled "Okovango" or "Okovanggo") in Botswana is a vast inland delta formed where the Okavango River reaches a tectonic trough at an altitude of {{convert|930|–|1000|m|ft}}{{cite web |title=Ramsar Information Sheet |url=https://rsis.ramsar.org/RISapp/files/RISrep/BW879RISformer.pdf |date=20 November 1996 |quote=The total drop in altitude between Mohembo and Maun, a distance of440 km, is only 62 metres, giving a gradient of approximately 1:7,000 only |access-date=17 January 2021 |archive-date=31 August 2021 |archive-url=https://web.archive.org/web/20210831015705/https://rsis.ramsar.org/RISapp/files/RISrep/BW879RISformer.pdf |url-status=live }} in the central part of the endorheic basin of the Kalahari Desert.
It is a UNESCO World Heritage Site as one of the few interior delta systems that do not flow into a sea or ocean, with a wetland system that is largely intact. All the water reaching the delta is ultimately evaporated and transpired. Each year, about {{convert|11|km3}} of water spreads over the {{cvt|6000-15000|km2|adj=on}} area. Some flood waters drain into Lake Ngami. The area was once part of Lake Makgadikgadi, an ancient lake that had mostly dried up by the early Holocene.
The Moremi Game Reserve is on the eastern side of the delta. The delta was named one of the Seven Natural Wonders of Africa, which were officially declared on 11 February 2013 in Arusha, Tanzania.{{cite web |url=http://sevennaturalwonders.org/africa |title=Seven Natural Wonders of Africa – Seven Natural Wonders |website=sevennaturalwonders.org |access-date=22 March 2013 |archive-url=https://web.archive.org/web/20151221103510/http://sevennaturalwonders.org/africa/ |archive-date=21 December 2015 |url-status=dead}} On 22 June 2014, the Okavango Delta became the 1000th site to be officially inscribed on the UNESCO World Heritage List.{{cite web |url=https://whc.unesco.org/en/news/1159 |title=World Heritage List reaches 1000 sites with inscription of Okavango Delta in Botswana |first=UNESCO World Heritage |last=Centre |website=whc.unesco.org |access-date=4 April 2018 |archive-date=26 July 2018 |archive-url=https://web.archive.org/web/20180726234253/http://whc.unesco.org/en/news/1159 |url-status=live }}{{cite web |url=https://whc.unesco.org/en/news/1162 |title=Twenty six new properties added to World Heritage List at Doha meeting |first=UNESCO World Heritage |last=Centre |website=whc.unesco.org |access-date=4 April 2018 |archive-date=26 July 2018 |archive-url=https://web.archive.org/web/20180726234247/http://whc.unesco.org/en/news/1162 |url-status=live }}
Geography
=Floods=
The Okavango is produced by seasonal flooding. The Okavango River drains the summer (January–February) rainfall from the Angola highlands and the surge flows {{cvt|1200|km}} in around one month. The waters then spread over the {{cvt|250|by|150|km|adj=on}} area of the delta over the next four months (March–June).
The high temperature of the delta causes rapid transpiration and evaporation, resulting in three cycles of rising and falling water levels{{cite web |author1=C. N. Kurugundla |author2=N. M. Moleele |author3=K.Dikgola |title=Flow Partitioning Within the Okavango Delta –A Pre-requisite for Environmental Flow Assessment for Human Livelihoods and Sustainable Biodiversity Management |url=https://www.water.gov.bw/images/Reports/Okavango_Delta.pdf |publisher=University of Botswana |pages=8–9 |access-date=17 January 2021 |archive-date=31 August 2021 |archive-url=https://web.archive.org/web/20210831015657/https://www.water.gov.bw/images/Reports/Okavango_Delta.pdf |url-status=live }} that were not fully understood until the early 20th century. The flood peaks between June and August, during Botswana's dry winter months, when the delta swells to three times its permanent size, attracting animals from kilometres around and creating one of Africa’s greatest concentrations of wildlife.
The delta is very flat, with less than {{cvt|2|m|ft|0}} variation in height across its {{cvt|15,000|km2}}, while the water drops about 60 m from Mohembo to Maun.{{cite journal |last1=Wehberg |first1=Jan |title=Okavango Basin - Physicogeographical setting |journal=Biodiversity and Ecology |date=31 December 2013 |volume=5 |pages=11 |doi=10.7809/b-e.00236 |doi-access=free}}{{cite journal |last1=Gumbricht |first1=T. |title=The topography of the Okavango Delta, Botswana, and its tectonic and sedimentological implications |journal=South African Journal of Geology |date=1 September 2001 |volume=104 |issue=3 |pages=243–264 |doi=10.2113/1040243|bibcode=2001SAJG..104..243G }}
=Water flow=
=Lagoons=
File:Shinde Lagoon, Okavango Delta, Botswana.jpg
When the water levels gradually recede, water remains in major canals and river beds, in waterholes and in a number of larger lagoons, which then attract increasing numbers of animals. Photo-safari camps and lodges are found near some of these lagoons. Among the larger lagoons are:
- Dombo Hippo Pool ({{coord|19|11|58|S|23|38|25|E}})
- Gcodikwe Lagoon ({{coord|19|10|03|S|23|14|24|E}})
- Guma Lagoon ({{coord|18|57|52|S|22|22|41|E}})
- Jerejere Lagoon/Hippo Pool ({{coord|19|05|17|S|23|01|12|E}})
- Moanachira Lagoon/Sausage Island ({{coord|19|03|23|S|23|03|44|E}})
- Moanachira Lagoon ({{coord|19|03|45|S|23|05|24|E}})
- Shinde Lagoon ({{coord|19|06|18|S|23|09|18|E}})
- Xakanaxa Lagoon ({{coord|19|10|48|S|23|23|42|E}})
- Xhamu Lagoon ({{coord|19|10|03|S|23|16|12|E}})
- Xhobega Lagoon ({{coord|19|10|39|S|23|12|36|E}})
- Xugana Lagoon ({{coord|19|04|12|S|23|06|00|E}})
- Zibadiania Lagoon ({{coord|18|34|12|S|23|32|06|E}})
=Salt islands=
The agglomeration of salt around plant roots leads to barren white patches in the centre of many of the thousands of islands, which have become too salty to support plants, aside from the odd salt-resistant palm tree. Trees and grasses grow in the sand around the edges of the islands that have not become too salty yet.
About 70% of the islands began as termite mounds (often Macrotermes spp.), where a tree then takes root on the mound of soil.{{Cite web |title=Nature explored:Moremi/Okavango Delta in August |url=http://www.nature-explored.com/moremi-okavango-august.htm |last=Dunford |first=Chris |access-date=29 May 2020 |archive-date=20 January 2022 |archive-url=https://web.archive.org/web/20220120055602/http://www.nature-explored.com/moremi-okavango-august.htm |url-status=live }}
=Chief's Island=
Chief's Island ({{coord|19|12|S|22|48|E}}), the largest island in the delta, was formed by a fault line which uplifted an area over {{cvt|70|km||long|adj=mid}} and {{cvt|15|km||wide|adj=mid}}. Historically, it was reserved as an exclusive hunting area for the chief, but is now a protected area for wildlife. It now provides the core area for much of the resident wildlife when the waters rise.{{Cite web |title=Okavango delta Botswana {{!}} Mokoro and boating safaris |url=https://okavangosafari.co.bw/ |website=Okavango Safaris |language=en-US |access-date=2020-05-29 |archive-date=20 January 2022 |archive-url=https://web.archive.org/web/20220120055446/https://okavangosafari.co.bw/ |url-status=live }}
Climate
The Delta's profuse greenery is not the result of a wet climate; rather, it is an oasis in an arid country. The average annual rainfall is {{cvt|450|mm}} (approximately one-third that of its Angolan catchment area) and most of it falls between December and March in the form of heavy afternoon thunderstorms.
December to February are hot wet months with daytime temperatures as high as {{cvt|40|C|}}, warm nights, and humidity levels fluctuating between 50 and 80%. From March to May, the temperature reduces, with a maximum of {{cvt|30|C|}} during the day and mild to cool nights. The rains quickly dry up leading into the dry, cool winter months of June to August. Daytime temperatures at this time of year are mild to warm, but the temperature falls considerably after sunset. Nights can be cold in the delta, with temperatures barely above freezing.{{Cite web |title=Botswana climate: average weather, temperature, precipitation, best time |url=https://www.climatestotravel.com/climate/botswana |website=www.climatestotravel.com |access-date=2020-05-15 |archive-date=20 January 2022 |archive-url=https://web.archive.org/web/20220120055436/https://www.climatestotravel.com/climate/botswana |url-status=live }} Frost is sometimes seen over the winter.https://www.naturalhistoryfilmunit.com/post/a-year-in-the-okavango-delta A Year in the Okavango Delta
The September to November span has the heat and atmospheric pressure build up once more, as the dry season slides into the rainy season. October is the most challenging month for visitors: daytime temperatures often push past {{cvt|40|C|}} and the dryness is only occasionally broken by a sudden cloudburst.{{Cite web |last=UNEP-WCMC |date=2017-05-22 |title=OKAVANGO DELTA |url=https://www.yichuans.me/datasheet/output/site/okavango-delta/|access-date=2021-05-17 |website=World Heritage Datasheet |language=en}}
Fauna of the delta
The Okavango Delta is both a permanent and seasonal home to a wide variety of wildlife which is now a popular tourist attraction. All of the big five game animals—the lion, leopard, African buffalo, African bush elephant and rhinoceros (both black and white rhinoceros)—are present.{{cite journal |last=Galpine |first=N. J. |year=2006 |title=Boma management of black and white rhinoceros at Mombo, Okavango Delta—Some lessons |journal=Ecological Journal |volume=7 |pages=55−61 |url=https://www.rhinoresourcecenter.com/pdf_files/120/1203674763.pdf |access-date=1 February 2020 |archive-date=7 February 2021 |archive-url=https://web.archive.org/web/20210207165941/https://www.rhinoresourcecenter.com/pdf_files/120/1203674763.pdf |url-status=live }}
Other species include giraffe, blue wildebeest, plains zebra, hippopotamus,{{cite journal |last1=McCarthy |first1=T. S. |last2=Ellery |first2=W. N. |last3=Bloem |first3=A. |year=1998 |title=Some observations on the geomorphological impact of hippopotamus (Hippopotamus amphibius L.) in the Okavango Delta, Botswana |journal=African Journal of Ecology |volume=36 |issue=1 |pages=44−56 |doi=10.1046/j.1365-2028.1998.89-89089.x|bibcode=1998AfJEc..36...44M }} impala, common eland, greater kudu, sable antelope, roan antelope, puku, lechwe, waterbuck, sitatunga, tsessebe, cheetah,{{cite journal |last=Klein |first=R. |year=2007 |title=Status report for the cheetah in Botswana |journal=Cat News |volume=Special Issue 1 |pages=13−21 |url=http://www.catsg.org/fileadmin/filesharing/3.Conservation_Center/3.2._Status_Reports/Cheetah/Klein_2007_Cheetah_in_Botswana.pdf |access-date=1 February 2020 |archive-date=31 August 2021 |archive-url=https://web.archive.org/web/20210831015402/http://www.catsg.org/fileadmin/filesharing/3.Conservation_Center/3.2._Status_Reports/Cheetah/Klein_2007_Cheetah_in_Botswana.pdf |url-status=live }} African wild dog, spotted hyena, black-backed jackal, caracal, serval, aardvark, aardwolf, bat-eared fox, African savanna hare, honey badger, crested porcupine, common warthog, chacma baboon, vervet monkey and Nile crocodile.{{cite journal |last1=Wallace |first1=K. M. |last2=Leslie |first2=A. J. |year=2008 |title=Diet of the Nile crocodile (Crocodylus niloticus) in the Okavango Delta, Botswana |journal=Journal of Herpetology |volume=42 |issue=2 |pages=361−368 |doi=10.1670/07-1071.1 |s2cid=46987629}}
The delta also hosts over 400 bird species, including the helmeted guineafowl, African fish eagle, Pel's fishing owl, Egyptian goose, South African shelduck, African jacana, African skimmer, marabou stork, crested crane, African spoonbill, African darter, southern ground hornbill, wattled crane,{{cite book |editor-last=Alonso |editor-first=L. E. |editor2-last=Nordin |editor2-first=L.-A. |year=2003 |title=A rapid biological assessment of the aquatic ecosystems of the Okavango Delta, Botswana: High Water Survey |series=RAP Bulletin of Biological Assessment |volume=27 |publisher=Conservation International |location=Washington, DC |isbn=1-881173-70-4}} lilac-breasted roller, secretary bird, and common ostrich.{{cite journal |last1=Mbaiwa |first1=J. E. |last2=Mbaiwa |first2=O. I. |year=2006 |title=The effects of veterinary fences on wildlife populations in Okavango Delta, Botswana |journal=International Journal of Wilderness |volume=12 |issue=3 |pages=17−41 |hdl=10311/28}} Prime bird-watching areas are those with a mix of habitats such as the panhandle, the seasonal delta and the parts of the Moremi Game Reserve that are close to the water.{{Cite book |last=Adrian |first=Bailey |title=OKAVANGO; Africa's Wetland Wilderness |publisher=Struik Publishers (Pty) Ltd |year=1998 |isbn=1868720411 |location=Cape Town, South Africa |pages=66–73}}
Since 2005, the protected area has been considered a Lion Conservation Unit together with Hwange National Park.{{cite book |author=IUCN Cat Specialist Group |year=2006 |title=Conservation Strategy for the Lion Panthera leo in Eastern and Southern Africa |publisher=IUCN |location=Pretoria, South Africa}}
In 1992, the black rhino was thought to be extinct in the Okavango Delta, while only 19 white rhinos remained.{{Cite news |title=Rhino in the Okavango |url=https://www.itravelto.com/rhino-okavango.html |publisher=Botswana Safari Tours |access-date=13 July 2023 |archive-date=13 July 2023 |archive-url=https://web.archive.org/web/20230713111925/https://www.itravelto.com/rhino-okavango.html |url-status=live }} By 1993, all rhinos had been killed in Botswana.{{cite web |url= https://www.independent.co.uk/voices/campaigns/giantsclub/botswana/botswana-s-imported-rhino-poaching-crisis-b2058230.html|title=Botswana's imported rhino poaching crisis |publisher=Independent |date=April 14, 2022|access-date=2014-07-19}}. Hundreds of white and black rhinos were reintroduced by the Botswana Rhino Reintroduction Project founded in 2000.{{cite web |url= https://www.independent.co.uk/voices/campaigns/giantsclub/botswana/botswana-s-imported-rhino-poaching-crisis-b2058230.html|title=Botswana's imported rhino poaching crisis |publisher=Independent |date=April 14, 2022|access-date=2014-07-19}}. From 2010 to 2018, seven rhinos were killed by poachers.{{cite web |url=https://www.bloomberg.com/news/articles/2021-10-23/botswana-moves-rhinos-out-of-okavango-delta-as-poaching-worsens |title=Botswana Moves Rhinos Out of Okavango Delta as Poaching Worsens |work=Bloomberg.com |first=Mbongeni|last=Mguni|date=October 23, 2021|accessdate=2024-07-19}} By 2019, the rhino population in Botswana had decreased to an estimated 400, with the largest population of roughly 150 living in the northern Okavango Delta.{{Cite news |title=Poaching, Natural Causes Decimate Botswana's Rhino Population |url=https://www.voanews.com/a/poaching-natural-causes-decimate-botswana-s-rhino-population/6972651.html |publisher=Voa News |access-date=13 July 2023 |archive-date=13 July 2023 |archive-url=https://web.archive.org/web/20230713113217/https://www.voanews.com/a/poaching-natural-causes-decimate-botswana-s-rhino-population/6972651.html |url-status=live }} From 2020 to 2021, 92 rhinos were killed by poachers in the delta region leaving only 40 individuals, prompting the government to move those rhinos out of the Okavango Delta.{{Cite news |title=Botswana Moves Rhinos Out of Okavango Delta as Poaching Worsens |url=https://www.bloomberg.com/news/articles/2021-10-23/botswana-moves-rhinos-out-of-okavango-delta-as-poaching-worsens |publisher=Bloomberg |access-date=13 July 2023 |archive-date=22 November 2022 |archive-url=https://web.archive.org/web/20221122041225/https://www.bloomberg.com/news/articles/2021-10-23/botswana-moves-rhinos-out-of-okavango-delta-as-poaching-worsens |url-status=live }}
File:Antílopes lechwes (Kobus leche), vista aérea del delta del Okavango, Botsuana, 2018-08-01, DD 27.jpg antelopes, Okavango Delta]]
The most abundant large mammal is the lechwe, with estimates suggesting approximately 88,000 individuals.{{cite report |author=Chase, M. |author2=Schlossberg, S. |author3=Landen, K. |author4=Sutcliffe, R. |author5=Seonyatseng, E. |author6=Keitsile, A. |author7=Flyman, M. |year=2018 |title=Dry Season Aerial Survey of Elephants and Wildlife in Northern Botswana |location=Botswana |publisher=Elephants Without Borders, the Department of Wildlife and National Parks and the Great Elephant Census |name-list-style=amp |url=https://www.researchgate.net/publication/307968091}} The lechwe a bit larger than an impala, with elongated hooves and a water-repellent substance on its legs that enable rapid movement through knee-deep water. Lechwe graze on aquatic plants and, like the waterbuck, take to water when threatened by predators. Only the males have horns.{{Cite web |title=Lechwe {{!}} mammal |url=https://www.britannica.com/animal/lechwe |access-date=2021-05-17 |website=Encyclopedia Britannica |language=en |archive-date=17 May 2021 |archive-url=https://web.archive.org/web/20210517164502/https://www.britannica.com/animal/lechwe |url-status=live }}
=Fish=
The Okavango Delta is home to 71 fish species, including the tigerfish, species of tilapia, and various species of catfish. Fish sizes range from the {{cvt|1.4|m|ft|adj=on}} African sharptooth catfish to the {{cvt|3.2|cm||adj=on}} sickle barb. The same species are found in the Zambezi River, indicating an historic link between the two river systems.{{cite web |url=http://www.orc.ub.bw/downloads/FS3_fish.pdf |title=Archived copy |access-date=2011-02-02 |url-status=dead |archive-url=https://web.archive.org/web/20110706162829/http://www.orc.ub.bw/downloads/FS3_fish.pdf |archive-date=6 July 2011 |df=dmy-all}}
Flora of the delta
The Okavango Delta is home to 1068 plants which belong to 134 families and 530 genera.{{Cite journal |last=Ramberg |first=Lars |date=2006 |title=Species diversity of the Okavango Delta,Botswana |url=https://www.researchgate.net/publication/226358917 |journal=Aquatic Sciences |volume=68 |issue=3 |pages=316 |doi=10.1007/s00027-006-0857-y |bibcode=2006AqSci..68..310R |via=ResearchGate}} There are five important plant communities in the perennial swamp: Papyrus cyperus in the deeper waters, Miscanthus in the shallowly flooded sites, and Phragmites australis, Typha capensis and Pycreus in between. The swamp-dominant species, which are usually found in the perennial swamp, also extend far into the seasonally inundated area. Papyrus cyperus reeds beds grow best in slow flowing waters of medium depth and are prominent at the channel sides. On the islands and mainlands edges above the flooded grasslands different communities of flora are found. These species are located according to their water preference: for instance Philenoptera violacea requires little water, is found at the highest elevations in the perennial swamps, and is common on drier seasonal swamp islands. Trees restricted to islands within the perennial swamp are a mixture of the palm Hyphaene petersiana and acacias.{{Cite journal |last=Toerien |first=D. K. |date=1976-08-15 |title=Geologie van die Tsitsikamakusstrook |journal=Koedoe |volume=19 |issue=1 |doi=10.4102/koedoe.v19i1.1179 |issn=2071-0771 |doi-access=free}}
The plants of the delta play an important role in providing cohesion for the sand. The banks or levees of a river normally have a high mud content, and this combines with the sand in the river’s load to continuously build up the river banks. The river’s load In the delta consists almost entirely of sand, because the clean waters of the Okavango contain little mud. The plants capture the sand, acting as the glue and making up for the lack of mud, and in the process creating further islands on which more plants can take root.
This process is not important in the formation of linear islands. They are long and thin and often curved like a gently meandering river because they are actually the natural banks of old river channels which have become blocked up by plant growth and sand deposition, resulting in the river changing course and the old river levees becoming islands. Due to the flatness of the delta and the large tonnage of sand flowing into it from the Okavango River, the floor of the delta is slowly but constantly rising. Where channels are today, islands will be tomorrow and then new channels may wash away these existing islands.
People
File:Travesía del delta del Okavango en makoro, Botsuana, 2018-08-01, DD 22.jpg on delta floodwaters]]
The Okavango Delta peoples consist of five ethnic groups, each with its own ethnic identity and language:
- the Hambukushu (also known as Mbukushu, Bukushu, Bukusu, Mabukuschu, Ghuva, Haghuva),
- the Dceriku (Dxeriku, Diriku, Gciriku, Gceriku, Giriku, Niriku),
- the Wayeyi (Bayei, Bayeyi, Yei),
- the Bugakhwe (Kxoe, Khwe, Kwengo, Barakwena, {{Proper name|G{{!}}anda}})
- the {{Proper name|ǁanikhwe}} (Gxanekwe, {{Proper name|ǁtanekwe}}, River Bushmen, Swamp Bushmen, {{Proper name|Gǁani}}, {{Proper name|ǁani}}, Xanekwe).
The Hambukushu, Dceriku, and Wayeyi have traditionally engaged in mixed economies of millet/sorghum agriculture, fishing, hunting, the collection of wild plant foods, and pastoralism.
The Bugakhwe and {{Proper name|ǁanikwhe}} are Bushmen, who have traditionally practised fishing, hunting, and the collection of wild plant foods; Bugakhwe used both forest and riverine resources, while the {{Proper name|ǁanikhwe}} mostly focused on riverine resources. The Hambukushu, Dceriku, and Bugakhwe are present along the Okavango River in Angola and in the Caprivi Strip of Namibia, and small numbers of Hambukushu and Bugakhwe are in Zambia, as well. Within the Okavango Delta, over the past 150 years or so, Hambukushu, Dceriku, and Bugakhwe have inhabited the panhandle and the Magwegqana in the northeastern delta. {{Proper name|ǁanikhwe}} have inhabited the panhandle and the area along the Boro River through the delta, as well as the area along the Boteti River.
The Wayeyi{{Cite web |title=Wayeyi |url=https://minorityrights.org/minorities/wayeyi/ |access-date=2021-06-02 |website=Minority Rights Group |date=19 June 2015 |language=en-GB |archive-date=2 June 2021 |archive-url=https://web.archive.org/web/20210602215842/https://minorityrights.org/minorities/wayeyi/ |url-status=live }} have inhabited the area around Seronga as well as the southern delta around Maun, and a few Wayeyi{{Cite journal |last1=Campbell |first1=Alexander Colin |last2=N’teta |first2=Doreen |date=March 1980 |title=The National Museum and Art Gallery, Gaborone, Botswana |url=http://dx.doi.org/10.1111/j.1468-0033.1980.tb01909.x |journal=Museum International |volume=32 |issue=1–2 |pages=61–66 |doi=10.1111/j.1468-0033.1980.tb01909.x |issn=1350-0775 |access-date=2 June 2021 |archive-date=6 September 2023 |archive-url=https://web.archive.org/web/20230906044710/https://www.tandfonline.com/doi/abs/10.1111/j.1468-0033.1980.tb01909.x |url-status=live }} live in their putative ancestral home in the Caprivi Strip. Within the past 20 years many people from all over the Okavango have migrated to Maun, the late 1960s and early 1970s over 4,000 Hambukushu refugees from Angola were settled in the area around Etsha in the western Panhandle.
The Okavango Delta has been under the political control of the Batawana (a Tswana nation) since the late 18th century.{{cite web |first=Moanaphuti |last=Segolodi |title=Ditso Tsa Batawana |date=1940 |url=https://www.academia.edu/12170767 |access-date=1 May 2015 |archive-date=6 March 2023 |archive-url=https://web.archive.org/web/20230306233801/https://www.academia.edu/12170767 |url-status=live }} Led by the house of Mathiba I, the leader of a Bangwato offshoot, the Batawana established complete control over the delta in the 1850s as the regional ivory trade exploded.{{cite journal |first=Barry |last=Morton |title=The Hunting Trade and the Reconstruction of Northern Tswana Societies after the Difaqane, 1838–1880 |journal=South African Historical Journal |volume=36 |year=1997 |pages=220–239 |doi=10.1080/02582479708671276}} Most Batawana, however, have traditionally lived on the edges of the delta, due to the threat that the tsetse fly poses to their cattle. During a hiatus of some 40 years, the tsetse fly retreated and most Batawana lived in the swamps from 1896 through the late 1930s. Since then, the edge of the delta has become increasingly crowded with its growing human and livestock populations.
''Molapos'' (water streams)
After the flooding season, the waters in the lower parts of the delta, near the base, recede, leaving moisture behind in the soil. This residual moisture is used for planting fodder and other crops that can thrive on it. This land is locally known as molapo.
During 1974 to 1978, the floods were more intensive than normal and flood recession cropping was not possible, so severe food and fodder shortages occurred. In response, the Molapo Development Project was initiated. It protected the molapo areas with bunds to control the flooding and prevent severe flooding. The bunds are provided with sluice gates so the stored water can be released and flood recession cropping can start.File:PD-icon.svg {{cite book |first1=L. F. |last1=Kortenhorst |display-authors=1 |first2=R. J. |last2=Oosterbaan |first3=L. H. |last3=Sprey |year=1986 |title=Development of flood-recession cropping in the molapo's of the Okavango Delta, Botswana |work=Annual Report 1986 |pages=8–19 |publisher=International Institute for Land Reclamation and Improvement |location=Wageningen, The Netherlands |url=https://www.waterlog.info/pdf/molapos.pdf |access-date=11 August 2017 |archive-date=10 August 2017 |archive-url=https://web.archive.org/web/20170810013033/https://www.waterlog.info/pdf/molapos.pdf |url-status=live }}
Possible threats
One possible threat is oil exploration by Canadian company ReconAfrica. Initial exploration in April 2021 revealed oil deposits in sedimentary rock.{{Cite web |last=Ltd |first=Reconnaissance Energy Africa |title=ReconAfrica's First of Three Wells Confirms a Working Petroleum System in the Kavango Basin, Namibia |url=https://www.newswire.ca/news-releases/reconafrica-s-first-of-three-wells-confirms-a-working-petroleum-system-in-the-kavango-basin-namibia-865139500.html |access-date=2021-04-27 |website=www.newswire.ca |language=en |archive-date=20 January 2022 |archive-url=https://web.archive.org/web/20220120055430/https://www.newswire.ca/news-releases/reconafrica-s-first-of-three-wells-confirms-a-working-petroleum-system-in-the-kavango-basin-namibia-865139500.html |url-status=live }} Environmentalists are concerned that the project will have a negative ecological impact and that some of the main bodies of water could be threatened.{{Cite web |title=A Big Oil Project in Africa Threatens Fragile Okavango Region |url=https://e360.yale.edu/features/a-big-oil-project-in-africa-threatens-the-fragile-okavango-region |access-date=2021-04-27 |website=Yale E360 |language=en-US |archive-date=20 January 2022 |archive-url=https://web.archive.org/web/20220120055427/https://e360.yale.edu/features/a-big-oil-project-in-africa-threatens-the-fragile-okavango-region |url-status=live }}{{Cite web |date=2021-03-22 |title=Growing concern over Okavango oil exploration as community alleges shutout |url=https://news.mongabay.com/2021/03/growing-concern-over-okavango-oil-exploration-as-community-alleges-shutout/ |access-date=2021-06-02 |website=Mongabay Environmental News |language=en-US |archive-date=20 January 2022 |archive-url=https://web.archive.org/web/20220120055426/https://news.mongabay.com/2021/03/growing-concern-over-okavango-oil-exploration-as-community-alleges-shutout/ |url-status=live }}{{Cite web |date=2021-03-12 |title=Test drilling for oil in Namibia's Okavango region poses toxic risk |url=https://www.nationalgeographic.com/animals/article/test-drilling-oil-namibia-poses-water-risk |access-date=2021-04-27 |website=Animals |language=en |archive-date=27 April 2021 |archive-url=https://web.archive.org/web/20210427143948/https://www.nationalgeographic.com/animals/article/test-drilling-oil-namibia-poses-water-risk |url-status=dead }}
ReconAfrica has stated, "There will be no damage to the ecosystem from the planned activities."{{cite web |title=Frequently Asked Questions: ReconAfrica Initial Drilling Project |url=https://reconafrica.com/operations/frequently-asked-questions/ |website=reconafrica.com |access-date=30 April 2021 |archive-date=29 April 2021 |archive-url=https://web.archive.org/web/20210429185250/https://reconafrica.com/operations/frequently-asked-questions/ |url-status=live }}{{Cite web |last=Wilson-Spath |first=Andreas |date=2020-12-15 |title=OP-ED: Paradise is closing down: The ghastly spectre of oil drilling and fracking in fragile Okavango Delta |url=https://www.dailymaverick.co.za/article/2020-12-15-paradise-is-closing-down-the-ghastly-spectre-of-oil-drilling-and-fracking-in-fragile-okavango-delta/ |access-date=2021-06-02 |website=Daily Maverick |language=en |archive-date=2 June 2021 |archive-url=https://web.archive.org/web/20210602220224/https://www.dailymaverick.co.za/article/2020-12-15-paradise-is-closing-down-the-ghastly-spectre-of-oil-drilling-and-fracking-in-fragile-okavango-delta/ |url-status=live }}
The Namibian government has presented plans to build a hydropower station in the Zambezi Region, which would regulate the Okavango's flow to some extent. While proponents argue that the effect would be minimal, environmentalists argue that this project could destroy most of the rich animal and plant life in the delta. Other threats include local human encroachment and regional extraction of water in both Angola and Namibia.{{cite web |url=http://www.okavangodelta.com/about/threats/ |title=Threats - Okavango Delta |website=www.okavangodelta.com |access-date=4 April 2018 |archive-date=22 February 2020 |archive-url=https://web.archive.org/web/20200222105527/https://www.okavangodelta.com/general-information/threats/ |url-status=dead}}{{cite web |url=http://www.macauhub.com.mo/en/2016/03/11/chinese-angolan-project-in-angola-harvests-over-1200-tons-of-rice/ |title=Chinese-Angolan project in Angola harvests over 1,200 tons of rice |work=Macauhub English |date=11 March 2016 |access-date=2 November 2016 |archive-date=4 November 2016 |archive-url=https://web.archive.org/web/20161104002158/http://www.macauhub.com.mo/en/2016/03/11/chinese-angolan-project-in-angola-harvests-over-1200-tons-of-rice/ |url-status=live }}
South African filmmaker and conservationist Rick Lomba warned in the 1980s of the threat of cattle invasion to the area. His documentary The End of Eden portrayed his lobbying on behalf of the delta.
The Okavango catchment is projected to experience decreasing annual rainfall as well as increasing temperatures as a result of global warming.{{cite book |author=ASSAR |year=2019 |title=What global warming of 1.5°C and higher means for Botswana |publisher=Adaptation at Scale in Semi Arid Regions (ASSAR) |url=http://www.assar.uct.ac.za/sites/default/files/image_tool/images/138/1point5degrees/ASSAR_Botswana_global_warming.pdf |access-date=6 August 2019 |archive-date=31 August 2021 |archive-url=https://web.archive.org/web/20210831015657/http://www.assar.uct.ac.za/sites/default/files/image_tool/images/138/1point5degrees/ASSAR_Botswana_global_warming.pdf |url-status=live }} The effects of global warming are likely to result in reductions in the extent of floodplains in the Okavango Delta, which will have significant impacts on water availability as well as livestock rearing and agricultural activities in the region.{{Cite journal |last1=Murray-Hudson |first1=M. |last2=Wolski |first2=P. |last3=Ringrose |first3=S. |date=2006 |title=Scenarios of the impact of local and upstream changes in climate and water use on hydro-ecology in the Okavango Delta, Botswana |journal=Journal of Hydrology |series=Water Resources in Regional Development: The Okavango River |volume=331 |issue=1 |pages=73–84 |doi=10.1016/j.jhydrol.2006.04.041 |bibcode=2006JHyd..331...73M}}
See also
{{Portal|Wetlands}}
References
{{Reflist|refs=
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Further reading
- {{cite book |first=P. |last=Allison |year=2007 |title=Whatever You Do, Don't Run: True Tales Of A Botswana Safari Guide |publisher=Globe Pequot |isbn=9780762745654 |url=https://archive.org/details/whateveryoudodon00alli |url-access=registration}}
- {{cite journal |first=J. |last=Bock |year=2002 |title=Learning, Life History, and Productivity: Children's lives in the Okavango Delta of Botswana |journal=Human Nature |volume=13 |issue=2 |pages=161–198 |doi=10.1007/s12110-002-1007-4 |pmid=26192757 |s2cid=28985956 |url=}}
External links
{{Commons category}}
{{Wikivoyage}}
- [http://www.conservation.org/xp/CIWEB/regions/africa/safrica.xml Conservation International]
- [https://www.okavango.com/concessions.php Okavango Delta concession areas]
- [http://flowhoorc.blogspot.com/ Flow : information for Okavango Delta planning is the weblog of the Library of the Harry Oppenheimer Okavango Research Institute]
- [https://web.archive.org/web/20160205022203/http://www.ngamitimes.com/ The Ngami Times is Ngamiland's weekly newspaper]
- [https://web.archive.org/web/20061006083431/http://www.botswana-tourism.gov.bw/attractions/moremi.html Official Botswana Government site on Moremi Game Reserve, inside the Okavango Delta]
- [https://web.archive.org/web/20170929000710/http://www.wildentrust.org/ Wild Entrust International]
- [https://web.archive.org/web/20151221103510/http://sevennaturalwonders.org/africa/ Seven Natural Wonders of Africa]
- [https://web.archive.org/web/20120319185832/http://dsc.discovery.com/tv/natures-most-amazing-events/how-stuff-works/kalahari-elephants.html Discovery Channel - Kalahari Flood]
- [http://www.waterlog.info/pdf/molapos.pdf Flood-recession cropping in the molapos of the Okavango Delta]
- [https://web.archive.org/web/20150401231635/http://www.orc.ub.bw/ Okavango Research Institute]
- [http://168.167.30.198/ori/ Current Okavango water levels, weather data and satellite images]
- [https://www.youtube.com/watch?v=_J-ODVl9Omg/ 1986 Documentary The End of Eden by Rick Lomba]
- [http://www.southern-african-game-reserves.co.za/botswana/okavango-delta/index.html Southern African Game Reserves - Okavango Delta]
{{Regions of Africa}}
{{Authority control}}
Category:River deltas of Africa
Category:Floodplains of Africa
Category:Ramsar sites in Botswana
Category:World Heritage Sites in Botswana