Okavango Delta

Delta Okavango ko Ciyawar Okavango wani babban fadamar cikin ƙasa ne a Botswana wanda ke fuskantar inda Kogin Okavango ya isa wani rami na tectonic a tsayin mita 930–1000 a tsakiyar ɓangaren kwarin hamada na Kalahari. Yana ɗaya daga cikin Guraren Gadon Duniya na UNESCO a matsayin ɗayan ƙananan tsarin delta na cikin gida waɗanda ba sa kwarara zuwa teku ko babban teku, tare da tsarin dausayi wanda ke da kariya sosai. Madadin haka, ruwan ambaliyar yana bazuwa a kan filayen yashi da tsibirai, kuma babban sashi yana shiga ƙasa zuwa cikin ruwan da ke ƙarƙashin ƙasa, kafin tsimrai su sha shi. Kusan dukkanin ruwan da ke isa delta daga ƙarshe yana bofewa ko kuma tsimrai suna fitar da shi. Kowace shekara, kusan kilomita mai siffar sili (km3) 11 na ruwa yana bazuwa a kan yanki mai faɗin murabba'in kilomita 6000-15000. Wasu ruwan ambaliyar suna kwarara zuwa Tabkin Ngami. Yankin ya taɓa zama ɗayan ɓangaren Tabkin Makgadikgadi, wani tsofaffi tabki wanda mafi yawansa ya kafe a farkon zamanin Holocene. Gidan Ajiyar Dabbobi na Moremi yana gefen gabas na delta. An ayyana delta ɗin a matsayin ɗaya daga cikin Abubuwan Al'ajabi na Halitta Guda Bakwai na Afirka, waɗanda aka sanar da su a hukumance ranar 11 ga Fabrairu 2013 a Arusha, Tanzania. A ranar 22 ga Yuni 2014, Delta Okavango ta zama guri na 1000 da aka rubuta a hukumance a cikin Jerin Gadon Duniya na UNESCO. Suna An samo sunan Okavango ne daga Kogin Okavango, wanda shi kuma sunansa ya fito ne daga Kavango, wanda ke nufin mutanen Kavango na arewacin Namibiya. Tsofaffin rubuce-rubucen Ingantattun kalmomi sun haɗa da Okovango, yayin da wasu masanan Namibiya suka fi son Kavango lokacin da suke magana game da kogi da yankin Namibiya. Masanin tarihi Andreas Eckl ya lura cewa rahotannin mallakar mallaka na Jamus sun yi amfani da Okavango, amma harafin farko O- ba ya da kyau a cikin harsunan Kavango na gida, kuma an danganta shi da tasirin harshen Herero. Labarin Ƙasa Ambaliyar Ruwa Okavango yana samuwa ne ta hanyar ambaliyar ruwa ta yanayi. Kogin Okavango yana ɗaukar ruwa daga ruwan sama na lokacin zafi (Janairu-Fabrairu) daga tsaunukan Angola kuma ambaliyar tana tafiyar kilomita 1200 a cikin kusan wata guda. Daga nan ruwan sai ya bazu a kan fili mai faɗin murabba'in kilomita 37500 na delta a cikin watanni huɗu masu zuwa (Maris-Yuni). Babban yanayin zafi na delta yana taimakawa wajen saurin bofewa da fitar da ruwa ta tsimrai, wanda ke haifar da hawan ruwa da sauka har sau uku waɗanda ba a fahimta sarai ba sai a farkon ƙarni na 20. Matakan ambaliyar sun kai kololuwa tsakanin Yuni da Agusta, lokacin sanyin hunturu na Botswana, lokacin da delta ke faɗaɗa har sau uku fiye da girmanta na dindindin, yana jan hankalin dabbobi daga kilomita da yawa kuma yana haifar da ɗayan mafi girman taron namun daji a Afirka. Delta ɗin tana da santsi sosai, tare da bambancin tsayi da bai kai mita 2 ba a faɗin murabba'in kilomita 15000, yayin da ruwan ke sauka kusan mita 60 daga Mohembo zuwa Maun. Kwararar Ruwa Tabkuna Lokacin da ruwan ya fara janyewa a hankali, ruwa yana kasancewa a manyan madatsun ruwa da gadoji na koguna, da kuma wasu manyan tabkuna, waɗanda ke ƙara janyo hankalin dabbobi masu yawa. Tsibiran Gishiri Taron gishiri a kusa da tushen tsimrai yana haifar da fararen wurare marasa amfani a tsakiyar dubun-dubatar tsibirai, waɗanda suka yi gishiri da yawa don tallafawa tsimrai, in ban da bishiyar dabino mai jure gishiri lokaci-lokaci. Bishiyoyi da ciyayi suna girma a cikin yashi a gefen tsibiran da ba su riga sun yi gishiri da yawa ba. Kusan kashi 70% na tsibiran sun fara ne a matsayin gidan gwano (kamar Macrotermes spp.), inda bishiyar take samun guri ta tsiro a kan gundumar ƙasa. Tsibirin Chief Tsibirin Chief (19°12′S 22°48′E), tsibiri mafi girma a cikin delta, ya samo asali ne ta hanyar layin fault wanda ya ɗaga wani yanki mai tsayin kilomita 70 da faɗin kilomita 15. A tarihi, an keɓe shi a matsayin gurin farauta na musamman ga sarki, amma yanzu yanki ne mai kariya don namun daji. Yanzu yana ba da babban yanki ga yawancin namun daji da ke zaune a wurin lokacin da ruwa ya tashi. Ilimin Ruwa (Hydrology) Hanyoyin shigowar ruwa na Delta Okavango sun samo asali ne mafi yawanci daga Kogin Okavango, wanda ke samuwa ta hanyar haɗuwar kogunan Cubango da Cuito a Angola kafin ya kwarara ta Namibiya zuwa Botswana. Bayan shiga delta kusa da Mohembo, kogin ya kasu kashi-kashi zuwa hadadden tsarin hanyoyin ruwa, filayen ambaliyar ruwa, tabkuna, da fadamomi na dindindin waɗanda ke dorewa ɗayan mafi girman delta na cikin ƙasa a duniya. Manyan hanyoyin rarraba ruwa sun haɗa da tsarin Boro, Maunachira, Thaoge, Santantadibe, Nqoga, da Jao. Waɗannan hanyoyin suna rarraba ruwan ambaliyar lokaci zuwa lokaci a duk faɗin delta, suna haifar da dausayi na dindindin da filayen ambaliyar ruwa waɗanda ke tallafawa rayayyun halittu masu yawa. Kusan kashi 96–98% na ruwan da ke shiga delta yana ɓacewa ta hanyar bofewa, shiga cikin ƙasa, da fitar ruwa ta tsimrai, yayin da kaɗan ne kawai ke barin tsarin ta hanyar kogunan Thamalakane da Boteti. Yanayi Koren dausayi na Delta ba sakamakon yanayi mai ruwa ba ne; a'a, wani guri ne mai albarka (oasis) a cikin ƙasa mai bushewa. Matsakaicin ruwan sama na shekara-shekara shine milimita 450 (kusan kashi ɗaya bisa uku na yankin da yake samo ruwa a Angola) kuma mafi yawansa yana sauka ne tsakanin Disamba da Maris a cikin nau'in tsawa mai ƙarfi da yamma. Disamba zuwa Fabrairu watanni ne masu zafi da ruwa tare da yanayin zafi na rana har zuwa digiri 40 na Celsius, daddare masu ɗumi, da matakan lagumi tsakanin kashi 50 da 80%. Daga Maris zuwa Mayu, yanayin zafi yana raguwa, tare da matsakaicin digiri 30 na Celsius da rana da daddare masu sanyi. Ruwan sama yana kafewa da sauri yana kaiwa ga lokacin rani na hunturu daga Yuni zuwa Agusta. Yanayin zafi na rana a wannan lokacin yana da sanyi zuwa ɗumi, amma yanayin zafi yana raguwa sosai bayan faɗuwar rana. Daddare na iya zama da sanyi sosai a cikin delta, tare da yanayin zafi da kyar yake gaba da daskarewa. Wani lokaci ana ganin sanyi (frost) a lokacin hunturu. Tsakanin Satumba zuwa Nuwamba, zafi da matsin lamba na sararin samaniya suna sake hauhawa, yayin da lokacin rani ke canzawa zuwa lokacin ruwa. Oktoba shine wata mafi wahala ga baƙi: yanayin zafi na rana yawanci yana wuce digiri 40 na Celsius kuma bushewar takan karye ne kawai lokaci zuwa lokaci ta hanyar ruwan sama na ba-zata. Dabbobin Delta Delta Okavango gida ne na dindindin da na lokaci-lokaci ga dabbobi daban-daban masu yawa. Dukkanin manyan dabbobi biyar na farauta (big five game), wato zaki, damisa, ɓaunar Afirka, giwar Afirka, baƙar fata da farar karkandan suna nan. Mafi yawan babban dabba mai shayarwa shine jan lechwe, tare da ƙididdiga da ke nuna kusan guda 88,000. Sauran jinsunan sun haɗa da rakumin dawa, wildebeest, jakin dawa, dorina, impala, eland, kudu, kurege, cheetah, karen daji na Afirka, kura, ɓiri, caracal, serval, damburi, gyatuma, kura-kura, kuregen Afirka, danyen zuma, alledawan daji, bika, biri da kada na Nile. Delta ɗin tana kuma ɗaukar nau'ikan tsuntsaye sama da 400, gami da zabuwa, gaggafa mai cin kifi na Afirka, mujiya mai cin kifi ta Pel, agwagin Masar, jacana na Afirka, marabou stork, jan baki, da jimina. Tun daga shekara da 2005, ana ɗaukar yankin da aka kare a matsayin Gidan Kare Zaki tare da Gidan shakatawa na Hwange. Zuwa shekara ta 2019, kusan karkandani 150 ne ke zaune a arewacin Delta Okavango. Daga 2020 zuwa 2021, masu farautar ba-shari'a sun kashe karkandani 92 a yankin delta wanda hakan ya bar guda 40 kacal, lamarin da ya sa gwamnati ta kwashe waɗancan karkandani daga Delta Okavango. Kifi Delta Okavango gida ne ga nau'ikan kifi 71, gami da kifin damisa, nau'ikan tilapia, da nau'ikan tarwada daban-daban. Girman kifi ya fito ne daga tarwada ta Afirka mai tsayin mita 1.4 zuwa sickle barb mai tsayin santimita 3.2. Hakanan irin waɗannan jinsunan suna faruwa a cikin Kogin Zambezi, wanda ke nuna tsohuwar alaƙa tsakanin tsarin kogunan biyu. Shuke-shuke (Flora) Delta Okavango gida ne ga shuke-shuke 1068 waɗanda ke cikin iyalai 134 da jinsi (genera) 530. Akwai muhimman rukunonin shuke-shuke guda biyar a cikin fadamar dindindin: Papyrus cyperus a cikin mafi zurfin ruwa, Miscanthus a guraren da ambaliyar ba ta da zurfi, da Phragmites australis, Typha capensis da Pycreus a tsakaninsu. Jinsunan da suka mamaye fadamar, waɗanda galibi ana samunsu a fadamar dindindin, suma yana faɗaɗa zuwa cikin yankunan da ambaliyar ke shafa lokaci-lokaci. Ciyawar Papyrus cyperus tana girma mafi kyau a cikin ruwa mai kwarara a hankali mai matsakaicin zurfi kuma suna fice sosai a gefen madatsun ruwa. A kan tsibirai da gefen manyan ƙasashe sama da ciyawar ambaliyar ruwa, ana samun rukunoni daban-daban na shuke-shuke. Waɗannan jinsunan suna samuwa ne gwargwadon buƙatarsu ta ruwa: misali Philenoptera violacea yana buƙatar ruwa kaɗan, ana samunsa a mafi tsayin wurare a fadamorin dindindin, kuma ya zama ruwan dare a tsibiran fadamar lokaci-lokaci mafi bushewa. Bishiyoyin da suka takaitu ga tsibirai a cikin fadamar dindindin cakuda ne na bishiyar dabino ta Hyphaene petersiana da acacias. Shuke-shuken delta suna taka muhimmiyar rawa wajen hana zaizayar ƙasa. Bankuna ko iyakokin kogi galibi suna da yumbu mai yawa, kuma wannan yana haɗuwa da yashi a cikin kayan kogin don ci gaba da gina bankunan kogin. Kayan kogin a cikin delta kusan gaba ɗaya yashi ne, saboda tsaftataccen ruwan Okavango ya ƙunshi laka ko yumbu kaɗan. Shuke-shuken suna kama yashin, suna aiki kamar manne kuma suna mayurbin rashin laka, kuma a cikin wannan tsari suna ƙirƙirar ƙarin tsibirai waɗanda ƙarin shuke-shuke za su iya yin tushiya a kai. Mutane Mutanen Delta Okavango sun ƙunshi ƙabilu biyar, kowanne yana da nasa asalin ƙabila da yare: Hambukushu (wanda kuma aka sani da Mbukushu, Bukushu, Bukusu, Mabukuschu, Ghuva, Haghuva), Dceriku (Dxeriku, Diriku, Gciriku, Gceriku, Giriku, Niriku), Wayeyi (Bayei, Bayeyi, Yei), Bugakhwe (Kxoe, Khwe, Kwengo, Barakwena, G|anda) ||anikhwe (Gxanekwe, ||tanekwe, Mutanen Dajin Kogi, Fadamar Daji, G||ani, ||ani, Xanekwe). Hambukushu, Dceriku, da Wayeyi a al'adance sun shagaltu da harkokin tattalin arziki na haɗin gwiwa da suka haɗa da noman hatsi/dawa, kamun kifi, farauta, tattara abincin shuke-shuken daji, da kiwon dabbobi. Bugakhwe da ||anikhwe mutanen daji ne (Bushmen), waɗanda a al'adance suke yin kamun kifi, farauta, da tattara abincin shuke-shuken daji; Bugakhwe sun yi amfani da albarkatun daji da na kogi, yayin da ||anikhwe suka fi mayar da hankali kan albarkatun kogi. Ana samun Hambukushu, Dceriku, da Bugakhwe a gefen Kogin Okavango a Angola da kuma a Caprivi Strip na Namibiya, sannan akwai ƙananan adadin Hambukushu da Bugakhwe a Zambiya ma. A cikin Delta Okavango, cikin shekaru 150 da suka gabata ko makamancin haka, Hambukushu, Dceriku, da Bugakhwe sun zauna a panhandle da Magwegqana a arewa maso gabashin delta. ||anikhwe sun zauna a panhandle da kuma yankin da ke gefen Kogin Boro ta cikin delta, da kuma yankin da ke gefen Kogin Boteti. Wayeyi sun zauna a yankin da ke kusa da Seronga da kuma kudancin delta kusa da Maun, kuma kaɗan daga cikin Wayeyi suna zaune ne a gidan iyaye da kakanninsu a Caprivi Strip. A cikin shekaru 20 da suka gabata mutane da yawa daga ko'ina cikin Okavango sun yi ƙaura zuwa Maun, a ƙarshen shekarun 1960 da farkon 1970s an tsugunar da 'yan gudun hijira Hambukushu sama da 4,000 daga Angola a yankin da ke kusa da Etsha a yammacin Panhandle. Delta Okavango tana ƙarƙashin ikon siyasa na Batawana (al'ummar Tswana) tun ƙarshen ƙarni na 18. Ubangidansu gidan Mathiba I ne ya jagorance su, shugaban wani reshe na Bangwato, Batawana sun kafa cikakken iko a kan delta a cikin shekarun 1850 yayin da cinikin hauren giwa na shiyya ya fashe. Yawancin Batawana, kodayake, a al'adance sun zauna ne a gefen delta, saboda barazanar da kudan tsando (tsetse fly) ke yi wa shanu su. A lokacin tazarar kusan shekaru 40, kudan tsando ya ja da baya kuma yawancin Batawana sun zauna a fadamomi kaɗan daga 1896 har zuwa ƙarshen shekarun 1930. Tun daga lokacin, gefen delta ya daɗa samun cunkoso saboda karuwar yawan mutane da dabbobi. Buɗe Ido da Yawon Buɗe Ido (Tourism) Dajin Delta Okavango da namun dajinta suna janyo daruruwan dubunnan masu yawon buɗe ido a duk shekara, inda garin Maun ke aiki a matsayin ƙofar shiga yankin. Yawon buɗe ido na safari na zamani ya haɓaka a ƙarshen shekarun 1960, lokacin da aka gina sansanonin safari na zamani na farko a cikin delta. Abubuwan yawon buɗe ido tun bayan faɗaɗawa sun haɗa da safaris na masauki masu daraja, safaris masu tafi-da-gidanka, sansanin tuka kai, kallon tsuntsaye, yawo don kallon dabbobi, jiragen sama na kallo, yawo na jagoranci, kamun kifi na nishaɗi, da balaguron kwale-kwale na makoro. Gaba ɗaya Botswana ta inganta tsarin yawon buɗe ido mai tsada amma na mutane kalilan a yankin Okavango, da nufin iyakance tasiri ga muhalli yayin da ake samun babban kuɗi daga baƙi. Rahoton UNESCO na 2014 ya gano cewa akwai gadajen masu yawon buɗe ido 2,129 a yankin. A shekarar 2017 delta ta karɓi baƙi 52,638, inda 43,363 daga cikinsu 'yan yawon buɗe ido ne na ƙasa da ƙasa sannan 9,275 kuma 'yan ƙasa ne. Wannan ƙaramin sashi ne kawai na 'yan yawon buɗe ido na ƙasa da ƙasa miliyan 1 da Botswana ke karɓa a kowace shekara. Molapos (Hanyoyin Ruwa) Bayannan lokacin ambaliya, ruwan da ke ƙananan sassan delta, kusa da gindinsa, yana janyewa, yana barin laushi ko danshi a cikin ƙasa. Ana amfani da wannan ragowar danshi don dasa ciyawar abincin dabbobi (fodder) da sauran amfanin gona da za su iya bunƙasa a kai. Wannan ƙasa an san ta a gida da suna molapo. A lokacin 1974 zuwa 1978, ambaliyar ta yi ƙarfi fiye da yadda aka saba kuma noman rani lokacin janyewar ruwa bai yiwu ba, don haka aka sami ƙarancin abinci da na abincin dabbobi mai tsanani. A matsayin martani, an ƙaddamar da Aikin Haɓaka Molapo (Molapo Development Project). Ya kare yankunan molapo da katangogi don sarrafa ambaliyar da kuma hana ambaliya mai tsanani. An samar da katangogin da ƙofofin ruwa (sluice gates) ta yadda za a iya sakin ruwan da aka tara kuma a fara noman lokacin janyewar ruwa. Barazanar da ke Tafe Wata barazana mai yiwuwa ita ce aikin binciken mai da kamfanin ReconAfrica na ƙasar Kanada ke yi. Binciken farko a watan Afrilu 2021 ya bayyana adadin mai a cikin duwatsun sedimentary. Masu fafutukar kare muhalli sun damu cewa aikin zai sami mummunan tasiri ga muhalli kuma wasu daga cikin manyan rukunonin ruwa na iya fuskantar barazana. ReconAfrica ta bayyana cewa, "Ba za a sami wata barna ga muhallin halittu daga ayyukan da aka tsara ba." Gwamnatin Namibiya ta gabatar da shirye-shiryen gina tashar samar da wutar lantarki ta ruwa (hydropower) a yankin Zambezi, wanda zai daidaita kwararar ruwan Okavango zuwa wani mataki. Yayin da masu goyon baya ke jayayyar cewa tasirin zai kasance kaɗan, masu fafutukar kare muhalli na jayayyar cewa wannan aikin zai iya lalata mafi yawan rukunonin dabbobi da shuke-shuke masu albarka a cikin delta. Sauran barazanar sun haɗa da katsalandan ɗin mutanen gida da kuma kwashe ruwa na shiyya-shiyya a kasashen Angola da Namibiya. Mai shirya fina-finai kuma masanin kiyayewa na Afirka ta Kudu Rick Lomba ya yi gargaɗi a shekarun 1980 game da barazanar mamayar shanu a yankin. Fim ɗinsa na gaskiya (documentary) mai suna The End of Eden ya nuna fafutukarsa a madadin delta ɗin. An yi hasashen cewa yankin da ke tattara ruwan Okavango zai fuskanci raguwar ruwan sama na shekara-shekara da kuma hauhawar yanayin zafi sakamakon dumamar yanayi. Illolin dumamar yanayi na iya haifar da raguwar filayen ambaliyar ruwa a Delta Okavango, wanda zai sami gagarumin tasiri ga wadatar ruwa gami da kiwon dabbobi da ayyukan noma a yankin. Ayyukan kiyayewa da ƙungiyar Conservation International Botswana ke yi a yankin Delta Okavango sun haɗa da ilmantarwa da sa hannu cikin manufofi gami da bincike da sanya idanu kamar binciken namun daji ta sararin samaniya da ayyukan tantance kwayoyin halitta cikin sauri. Manazarta