Bamwe bemera ko ari ibirenge by’imana, abandi ko ari inziga (uruziga) zakozwe n’imbyino z’ibisabantu byo mu kirere, ariko nta muntu urabasha gusobanura ibya za miliyoni z’inziga z’amayobera ziri muri ubu butayu.
Ni ubutayu buherereye mu Majyepfo ashyira Uburengerazuba bwa Africa ku nkombe z’inyanja ya Atlantika. Ubutayu bwa Namib ni hamwe mu hantu humagaye cyane kurusha ahandi ku isi.
Namib bisobanuye “ahantu hatari ikintu na kimwe” mu rurimi rwaho rwa Namba, aha hantu hameze nko ku mubumbe wa Mars hari amabimba manini cyane y’umucanga wo mu butayu, imisozi y’ibitare, n’imirambi y’amabuye. Ni ubutayu bwa kilometero kare 81,000 bukora ku bihugu bitatu, Angola, Namibiya na Afurika y’epfo.
Ku myaka miliyoni 55 ibarwa ko bumaze, Namib ifatwa nk’ubutayu bumaze imyaka myinshi kurusha ubundi bwose ku isi (ubutayu bwa Sahara bubarwa ko bumaze imyaka hagati ya miliyoni ebyiri na zirindwi gusa).
Mu gihe cy’impeshyi ubushyuhe busanzwe buba buri kuri degere celicius 45 mu gihe ijoro rikonja bikomeye cyane, ni hamwe mu hantu hafatwa nk’ahadashoboka na busa guturwa kuri uyu mubumbe.
Nyamara, uko imyaka yagiye ishira, hari amoko y’ibinyabuzima yahagize imuhira, maze bituma haboneka ibintu by’imiterere idasanzwe n’ubu abahanga batarasobanukirwa.
Aho inyanja igonganira n’ubutayu
Ubutayu bwa Namib bufite uburebure burenga kilometero 2,000 kuva mu majyepfo ya Angola ugaca muri Namibia kugera mu majyaruguru ya Africa y’Epfo.
Ku mwaro w’inyanja muri Namibia hari ahareshya na 160km aho ubu butayu bugarukira neza neza ku nkombe z’inyanja. Ishusho y’iri huriro ni umwihariko kandi ni urukererezabagenzi, iboneka nk’igitangaza kitari henshi ku isi.
Hari inyamaswa zihashoboye
Ibice byumagaye cyane bya Namib bigira igipimo rusange cy’imvura ya milimetero 2 gusa ku mwaka. Hashobora kandi gushira n’imyaka nta na gacye kaguye.
Ariko mu kuboneka kudasanzwe inyamaswa nk’impyisi, intarangwe (guépards/Cheetahs), inyoni za ostriches/autruches, imparage, impala, n’ingeragere zaremye uburyo zibasha kuba muri ubu buzima bukomeye cyane bwo muri ubu butayu.
Ostriches zizamura ubushyuhe bw’umubiri wazo kugira ngo bigabanye uko zitakaza amazi, imparage zo mu misozi yaho zibasha kurira, naho ingeragere zaho zishobora kumara ibyumweru zitanyoye amazi kubera kurya ibimera biyafite nk’imizi n’ingeri z’ibimera.
Amarembo y’ikuzimu
Hamwe mu hantu hakarishye cyane muri ubu butayu bw’intaturwa bwa Namib ni ahantu hareshya na 500km hari amabimba manini y’umucanga n’amato yatawe cyera cyane ku nkengero z’inyanja ya Atlantika hazwi cyane nka Skeleton Coast.
Aha hahera mu Majyepfo ya Angola kugeza hagati muri Namibia, izina ryaho riva ku bisigazwa byinshi by’amagufa y’amafi ya rutura (whales/baleines) ari aho ku mwaro hamwe n’amato hafi 1,000 yatawe cyera cyane, byose bihamaze imyaka amagana.
Aka gace ka Skeleton Coast gakunze kuba kabuditse ibicu bitsitse, biva ku mivumba ikonje y’inyanja ya Atlantika iza igasekurana n’umwuka ushyushye uvuye mu butayu bwa Namib.
Ibi bicu bituma amato agorwa cyane no kunyura aha hantu, kandi abantu bacye batuye hafi aho bitwa aba ‘San’ bahita “ubutaka Imana yaremye irakaye”.
Agenda n’ubwato ku nkengero z’iburengerazuba bwa Africa, umushakashatsi wo muri Portugal Diogo Cão yahagaze igihe gito kuri Skeleton Coast mu 1486.
Nyuma y’uko Cão n’abagabo bari kumwe nawe bahashinze umusaraba ariko inkubi z’umuyaga wuzuye umucanga n’ikirere kibi cyane cya hano byatumye bahita bihutira gusubira mu nyanja, gusa basiga bahabatije izina ryamenyekanye cyane; “Amarembo y’Ikuzimu”.
Amabimba atangaje y’umucanga
Uyu munsi, abakerarugendo bajya muri Namib kureba amabimba rutura atangaje y’umucanga ahitwa Sossusvlei, agace k’umunyu n’ibumba kari hagati muri Namib muri Parike y’igihugu yitwa Namib-Naukluft – parike ya gatatu nini muri Africa ifite ubuso bwa kilometero kare 50,000.
Mu gihe amabimba y’umucanga ari hose muri ubu butayu bwa Namib, ayo muri Sossusvlei afite umwihariko w’ibara rijya kuba ‘orange’. Iri bara mu by’ukuri riri hagati y’umutuku n’umuhondo, risobanura uburyo muri ubu butaka haba harimo ubutare bwinshi cyane.
Amabimba yo muri aka gace ni amwe mu manini cyane ku isi. Menshi ashobora kurenga 200m z’uburebure, mu gihe iryo bita “Dune 7”, riri mu majyaruguru ya Sossusvlei rifite ubutumburuke bwa metero hafi 400 mu kirere.
Inziga z’amayobera
Mu bitangaza bya Namib, kimwe mu biteye amatsiko n’amayobera akomeye y’uko byabayeho ni icyo bita “inziga z’amayobera.”
Rimwe na rimwe bazita kandi “impeta z’amayobera”, ni inziga zikozwe n’ubwoko bumwe bw’ikimera (ibyatsi) ziboneka hose mu butayu bwa Namib kandi zashobeye inzobere ku buryo zikoze n’impamvu.
Izi nziga ziboneka neza uri mu kirere, aho ubona ko zifite ishusho imwe kandi aho ziba zegeranye zitarutana cyane.
Izi nziga zifite umurambararo uri hagati ya metero 1.5 na 6m hagati muri Namib, naho mu majyaruguru ashyira uburengerazuba bwa Namibia, ho usanga ari nini kuko zishobora no kugera ku murambararo wa 25m.
Mu myaka myinshi cyane byari bizwi ko izi nziga zibaho muri Namibia, ariko mu 2014 izindi nkazo zavumbuwe muri Australia ubwo Bronwyn Bell umuhanga muri siyanse y’ibidukikije yariho yiga ku gace kadatuwe kitwa Pilbara.
Uyu yatangajwe n’izi nziga, maze uyu mugore avugana na Stephan Getzin, umuhanga mu bumenyi bw’isi wo mu Budage ngo amubwire ibyo yavumbuye.
Mu gihe izi nziga zo muri Australia zisa cyane n’izo muri Namibia, itandukaniro riri mu bigize ubutaka ryarushijeho gushobera abahanga.
Ibirenge by’imana Mukuru?
Mu gihe inzobere zigishobewe n’impamvu habaho izi nziga zidasanzwe, abaturage baho bo muri Namibia barazizi. Aba-Himba bemera ko ziva ku myuka, ko ari ahakandagiwe n’imana yabo yitwa Mukuru.
Mu gushaka kumenya imvo yazo, abahanga mu mibare bagerageje kubara ngo barebe niba izi nziga hari umujyo runaka zikurikiza, ariko Hein Schultz, nyiri ikigo Rostock Ritz Desert Lodge kiri hanze gato ya Parike ya Namib-Naukluft, asobanura ko bamwe mu bahatuye bemera ko izi nziga z’amayobera “ziterwa n’ibinyabuzima byo mu kirere bihabyinira nijoro”.
Ukuri kurahari?
Kugeza ubu, nta ngingo yemeranywaho y’impamvu cyangwa inkomoko y’izi nziga. Ariko mu myaka ya vuba aha, abahanga muri siyanse bo muri Namibia, Ubudage na Leta Zunze Ubumwe za Amerika n’ahandi bagiye hamwe ngo bige iki kintu bizeye kumva impamvu yacyo.
Mu kigo Gobabeb – Namib Research Institute, kiri kure hagati muri ubu butayu, inzobere mu kwiga inigwahabiri (insects) Eugene Marais asobanura ko ibitekerezo bibiri by’ingenzi ku kibitera bishingiye ku bucye cyane bw’amazi muri Namib.
Ubushakashatsi bumwe buvuga ko izi nziga ziterwa n’imiswa (termites) zikora izi nziga kugira ngo zikamure amazi n’ibindi byazitunga mu butaka. Mu kwigizayo ibimera byose biri ku butaka, imiswa ikora ahantu hambaye ubusa ku butaka, ibituma iyo imvura iguye amazi agera kure mu butaka.
Iki gitekerezo kivuga ko iyo miswa ibasha gukomeza kubona icyo inywa mu gihe cy’umwaka kivuye muri ibyo ‘bigega’ byo munsi y’ubutaka yakoze.
Ikindi gitekerezo cy’ingenzi ni uko “ibyatsi gutya byirema ubwabyo”, aho guhatana kw’imizi yabyo gutera inziga zituma bibasha no kubona aho bikura ibibitunga n’amazi mu gace k’ubutaka gusa kabikikije. Ubushyuhe n’ubukonje byombi bikabije biba muri ubu butayu butuma kuhatura bisa n’ibidashoboka
Iyobera ritarasobanuka
Nyuma y’imyaka y’amapfa akabije, ibyatsi bya za nziga z’amayobera bishobora kuma ndetse bikavaho bigashiraho. Maris asobanura ko igitangaje cy’aha hantu ari uko iyo imvura iguye, ako kanya “nk’ibidasanzwe” za nziga zihita zigaruka.
Kubwa Marais, ubushakashatsi kuri izi nziga za Namib muri rusange bwibanze ku bice bimwe na bimwe by’ubu butayu. Yemera ko kugira ngo hazamenyekane neza uburyo izi nziga zibaho bizasaba kwagurira ubu bushakashatsi mu bice byose by’imiterere y’ubu butayu.
Marais atekereza ko ibi bintu bidasanzwe bitatse ubu butayu biterwa n’ibintu byinshi. Ariko kumenya neza ibyo ari byo kugeza ubu biracyari inshoberabahanga.
Kanda hano usure izindi nkuru zacu mu mashusho.
src: BBC
Titi Leopold