 Tafkin Makgadikgadi | ||||
|---|---|---|---|---|
paleolake(en) | ||||
 | ||||
| Bayanai | ||||
| Basin country(en) | Botswana | |||
| Ƙasa | Botswana | |||
| Wuri | ||||
| ||||
Tafkin Makgadikgadi (məˈkɑːdiˈkɑːdi) ya kasance wanipaleolake wanda ya wanzu a inda yanzu yakeHamadar Kalahari aBotswana daga shekaru 2,000,000 BP zuwa 10,000 years BP. Wataƙila ya taɓa rufe yanki daga 80,000 zuwa 275,000 km2 (30,888 zuwa 106,178 sq mi) kuma zurfin 30m.[1] KogunanOkavango,UpperZambezi, daCuando duk sun kaɓu cikin kogin. Ana ganin burbushin sa a cikinkwanon gishirin Makgadikgadi, ɗayan manyan kwanukan gishiri a duniya.
BincikenDNA ya nuna yankin tafkin shine mahaifarHomo sapiens, inda suka fara juyewa zuwa wani jinsi na daban kimanin shekaru 200,000 da suka gabata, sannan suka fadada zuwa wasu sassan Afirka kimanin shekaru 70,000 daga baya.[2][3]
Kimanin shekaru miliyan 3 da suka gabata, iska mai karfi ta gabas ta kafa dogayendunes, wanda ya tashi daga gabas zuwa yamma a ƙetaren tsakiyar Hamada Kalahari. A lokacin damina, wadannandunes suna haɗa manyan rafuka na yankin, da Okavango,Chobe, da Upper Zambezi, kudu maso gabas don haɗuwa daKogin Limpopo kuma suna malala zuwaTekun Indiya.[4]
Botswana ta Arewa tana da jerin layuka masu zurfin gudana a ƙarƙashin rairayinta. Wadannan kuskuren ana tsammanin su ne mafi girma na kudu na tsarin guda na layukan masu layi daya wadanda suke kawar da juna kuma suka samar da babbar kwarin gabashin Afirka.[5] Bangarorin kwasa-kwasanKogin Linyanti da Kogin Chobe, suna nuna layin waɗannan laifofin a yau.[5]
Kimanin shekaru miliyan 2 da suka gabata, kuskuren da aka sani da layin Ovamboland-Kalahari-Zimbabwe (wanda ya tashi daga NE zuwa SW daga Harare zuwa Bulawayo kuma ya ƙare a gabashin gabashinHamadar Kalahari) ya motsa a cikin juzu'i na igiya, kuma ya yanke magudanan ruwa hanya zuwa cikin Limpopo. Fitowar fitowar ta ba da izinin ƙirƙirar Tafkin Makgadikgadi.
Babban an Sand ɗin Magwikwe tsakanin Savuti da probablyofar Arewa tabbas an bayyana ɗayan manyan yankuna kudu maso yamma. Wani kuma ana tsammanin shine Gidikwe Sand Ridge wanda ba a bayyane yake ba wanda yake kwance yamma da iyakar yamma na Filin shakatawa na Makgadikgadi na yanzu.
Za a iya samun abubuwan da aka wanke da kujeru a wurare da yawa na manyan tsaffin Kalahari a cikin wannan yankin. Gabashin gabashin tsauninGhoha, arewacin Savuti, babban misali ne na wannan. Hakanan ana iya samun duwatsu masu narkewar ruwa.
Yayinda shekaru dubu suka shude, tabkin ya cika iya karfinsa. Ya fara malalawa kimanin shekaru 20,000 da suka gabata, yana ɗaukar mafi ƙanƙanci a cikin maɓuɓɓugar ruwa a arewa maso gabas a matsayin sabon mashigarsa. Wannan ya sa Tsakiya da ƙananan Zambezi suka haɗu, suka zama Victoria Falls. Tare da ruwan da yanzu zai iya zubowa daga tafkin, Tafkin Makgadikgadi ya malale wani bangare kuma matsakaicin matakinsa ya ragu.[6]
Wani yanayi mai bushewa ya biyo baya, wanda ya haɓaka ƙarancin ruwa da rage rafin kogunan da ke ciyar da tabkin. Zuwa kimanin shekaru 10,000 da suka gabata bushewar Tafkin Makgadikgadi ya kasance a mataki na ci gaba. Mararraki da tarkace daga Kogin Okavango da yashi mai iska a hankali suna cika tafkin.[5]
Laifin Gumare ya kafa kuma ya saukar da ƙasar. A sakamakon haka, ruwan Kogin Okavango ya bazu a kan wani yanki mai girman gaske fiye da yadda yake a da, inda ya zama halin halayyar mai fankar a yanzu a cikin yankin Okavango, wanda ya kara rage ruwan da ke kwarara zuwa Tafkin Makgadikgadi kuma ya hanzarta rasuwa.
A watan Oktoba 2019 wata tawaga karkashin jagorancin Vanessa Hayes ta gabatar da cewa filayen da ke kusa da Tafkin Makgadikgadi shine yankin da yan Adam na zamani (homo sapiens) suka fara kirkira. Abubuwan da aka samo sun dogara ne akan samfurin 1,217 namitochondrial DNA, wanda aka ɗauka daga alƙarya a Kudancin Afirka. Masu binciken sun iya gano inda asalin mahaifarHomo Sapiens na zamani ya fito, kimanin shekaru 200,000 da suka gabata. Sun kammala wannan a yankin da ke kudu da Kogin Zambezi, wanda ya haɗa da wasu sassan da a yanzu ake kira Botswana, Namibia, da Zimbabwe. Wannan yayi daidai da gabar tsohuwar Tafkin Makgadikgadi.[7]
Chris Stringer, shugaban asalin mutum a gidan tarihin tarihin da ke Landan, da kuma Sarah Tishkoff, masaniyar kwayar halitta a Jami'ar Pennsylvania, ba su yarda da batun ba.[8][3]
An samo rarar ayyukan homo sapiens na farko a tsaunin Ga-Mohana a Arewacin Cape mai kwanan wata zuwa shekaru dubu 105 da suka gabata.[9]
Tafkin Makgadikgadi an kaddara cewa shine asalin mahaifar yawancincichlids wadanda suka taba yin ambaliyarKogin Congo,Kogin Zambezi,Kogin Okavango daKogin Limpopo-kusan sabbin nau'in 100 zuwa 400, wanda kusan 25 suka rayu a yau.[10] Girman tafkin na iya samar wa kakannin waɗannan kifaye da kewayon keɓaɓɓun mahalli don amfani da su kuma don haka zai iya kasancewa ya zama abin motsawa ga haɓakar sabon nau'in, wanda watakila sun yi a cikin rikodin lokaci kafin tafkin. drained gaba daya. Ka'idar ta ci gaba da cewa sabbin halittun, bayan sun canza cikin iyakokin tabkin, suna iya tserewa da ruwan tafkin yayin da yake malala, kuma sun mamaye kogunan yankin don zama cichlids da suke a yau.
A wannan lokaci na wannan ƙasar ana lalata shi mafi yawan shekara kuma lokaci ne mai dausayi a cikin watannin bazara mai damina.[11]
A yau ragowar tafkin Makgadikgadi su ne: Delta Okavango, Nxai Pan,Tafkin Ngami,Tafkin Xau, Mababe Depression, da kuma manyan Makgadikgadi biyu: Sua Pan da Nwetwe Pan.
Gandunan Gishirin Makgadikgadi suna daga cikin manya a duniya kuma an samar dasu ne daga ragowar karshen wannan babban tafki. Kogin Okavango yana da matukar girma, fadama a cikin gaci mai nisa wandakogin Okavango ya isa tsohon gadon tabkin. Yanzu ya zama babban kwandon ruwa wanda duk ruwan dake isa gareshi daga karshe ya bushe kuma ya gudana.
Sauran kogunan da ke malala daga kudu wadanda a da suke ciyar da tabkin a yanzu duk Zambezi ya kama su.
