Imwe yenzizi dzinozivikanwa kwazvo pasi rose yekuve ine simba kwazvo uye rwizi rukuru muSouth America ndiyo Rwizi rweAmazon. Chikonzero chiri rwizi rukuru pasi rose nekuti rwunotakura mvura yakawanda kupfuura rwizi, Yangtze uye iyo Mississippi pamwe chete. Kuve rwizi rukuru rwakadai uye nebheseni rakakura kudaro rehydrographic, inopa chikafu dunhu rese uye zviuru zvemarudzi ezvipenyu, mazhinji acho asati arongwa.
Muchikamu chino tiri kuzokuudza nezvese hunhu, geology uye kuumbwa kweRwizi rweAmazon.
Mhando huru
Irwizi rwuri muSouth America uye mvura hombe yainayo yakachena. Inoyerera ichibva kuAndes muPeru, uko mvura inonyungudika inodyisa rwizi urwu pa kureba kwemamita angangoita zviuru zvitanhatu. Rwizi urwu rwunoyerera mudunhu rese kuenda kuBrazil, kunova ndiko kwarunodurukira mu Atlantic Ocean. Zvinogona kutaurwa kuti bheseni rehydrographic rerwizi urwu rwakakura kupfuura chero rwizi rwumwe. Iine zviyero zvemamirioni manomwe emamirimita. Ndokunge, iyo hydrographic basin yeRwizi rweAmazon inovhara 40% yenharaunda yese yeSouth America.
Mukufamba kwayo kwese inopfuura nemunzvimbo dzeBrazil, Bolivia, Colombia, Ecuador, Guyana, Venezuela, Peru neSuriname. Nyika idzi dzese dzinotora mukana wemvura yeRwizi rweAmazon neimwe nzira. Uku ndiko kukosha kwerwizi urwu, rwakatenderedza, sango rese rinotambanuka inozivikanwa pasi rese sepapu repasi.
Inofungidzirwa kuti avhareji yemvura inoburitsirwa muAtlantic ingangoita 209.000 cubic metres pasekondi yemvura, inova ingangoita 6591 cubic kilometres pagore. Iyi huwandu hwemvura hunobatsira uye hwabatsira vanhu vemo munhoroondo yese kuti vagadzire vanhu vakatenderedza nzizi. Sezvinozivikanwa, munguva dzekare kosi yemvura yakatsiga yaidikanwa kugadzirira uye nekumisikidza huwandu hwayo hwakatenderedza. Dai mvura yaisagona kuve nehunyanzvi hwevanhu.
Kudzika kwerwizi kunosiyana mune dzimwe nzvimbo. Izvo zvakaderera zvikamu zvakanyorwa pakadzika kwemamita makumi maviri, nepo nzvimbo dzakadzika dzinosvika 90-100 metres. Iyo hupamhi yaizopawo munzira yayo. Kune nzvimbo, kunyanya pakutanga, dzine hupamhi hwemakiromita angangoita 1.6. Nekudaro, iyo yekuwedzera upamhi yakanyorwa makiromita gumi. Izvo zvinofanirwa kucherechedzwa kuti mukati memwaka wemvura kuyerera kwerwizi kunokura zvakanyanya uye kunoita hupamhi hwainogona kusvika inosvika kumakiromita makumi mashanu.
Kugona kuchengeta huwandu hwakawanda hwemvura, zvinodikanwa kuve nemitero yakawanda. Uye ndeyekuti Rwizi rweAmazon rune mitero zana nemazana nematanhatu pamwe chete nemakiromita anopfuura mazana matanhatu nemazana mana pakureba. Mimwe yemitero mikuru inova ndiyo nzizi dzinopa mvura yakawanda ndeyenzizi dzeNapo, Pastaza, Caquetá, Chambira, Tapajós, Nanay neHuallaga. Iyo yakareba mutero weAmazon iRwizi Madeira.
Kunyangwe iri rwizi rukuru pasi rose, inoramba ichirwira nzvimbo yekutanga nerwizi rweNile mune hurefu. Kwakatangira rwizi urwu hakusati kwanyatsojeka, saka zvichiri kudavirwa kuti rwizi Nile ndiro rakareba kupfuura mamwe ese pasi.
Kuumbwa kweRwizi rweAmazon
Iyo yakazara fluvial system yerwizi urwu inoumbwa nerwonzi rwizi uye nemitero yayo yese. Matare anoreva mitero inopa kuyerera kwemvura kurwizi rukuru. Rwizi urwu harusi kufamba munzira yakatwasuka asie iri kugadzira chimiro chinomira kubva kuPeruvia Andes kuchamhembe uyezve kumabvazuva. Kukombama kweaya mamandering manhamba anozivikanwa semamanders. Aya meanders akapfuma mune yakasikwa zvinhu sezvo paine akawanda masese ari kuzorova nekupa chimiro kune zororo idzva.
Aya maandi anokanganisa nzvimbo dzese dzakatenderedza nekufamba kwenguva. Nenzira yekuti, pamusoro pemakore uye makore ekukurwa kugume uye kugadzirisa nzvimbo yese uye, nekudaro, zvakare inokanganisa zvisikwa. Uye ndizvozvo, zvinoenderana nemvura yekunaya yegore negore uye nehutongi hwekunaya uye kusimba Tinogona kuona kuti simba rekushandura rerwizi rweAmazon rwakakosha.
Iyo system inobatanidzwa ne Orinoco rwizi uye inoramba ichiyerera kusvikira yaita delta inosvika makiromita mazana matatu pakureba. Zvinogona kutaurwa kuti haina dhiraidhi pachayo, asi iwo mafungu eAtlantic Ocean uye nesimba remafungu anoitadzisa kuti iiswe mumatope. Chimwe chezvinhu zvikuru zverwizi urwu ndechekuti, pamwe nekufamba kwayo, ine mapopoma uye mapopoma anoita kuti kufamba kunetse. Izvi zvinokonzerwa nekuti kuiswa kweiyo nyowani kuyerera nemitero kunokonzera nzvimbo dzenzvimbo dzemvura.
Kune dzakawanda zvidzidzo zve geological zvinoratidza kuti rwizi rweAmazon rwakatanga mukati menguva yeMiocene. Izvi zvakaitika makore gumi nemaviri apfuura. Iyo yakazvarwa zvakanyanya senge rwizi rwe transcontinental panguva iyo yanhasi South America ne Africa zvakabatanidzwa mune imwechete supercontinent inozivikanwa seGondwana. Zvinofungidzirwa kuti nekuda kwekurerekera, rwizi rweAmazon rwakaerera kubva kumabvazuva kuenda kumadokero uye kwete sezvavari kuita nhasi.
Kukwidziridzwa kwenyika uye kuumbwa kweAndes kwakaitika pakupera kwe cretaceous nguva. Izvi zvakaitika semhedzisiro yekurovera kwema tectonic mahwendefa anozivikanwa seNazca uye ndiro yekuSouth America. Kunetsana uku kwamahwendefa zvakakonzera kuti mvura yese ishanduke ive gungwa remukati uye izvo, zvishoma nezvishoma, zvaiwana hunhu hwehusope. Paive ipapo apo, makore gumi nemana emamiriyoni apfuura, mvura yaigona kuyerera ichienda kunzvimbo dzakaderera nekuda kwekuvharika kwaivepo kwekuyerera kwemvura kwakakonzerwa neAndes uye pakupedzisira ichidira mugungwa.
Chimiro chazvino cheRwizi rweAmazon chakasvika makore angangoita mamirioni 2.4 apfuura. Izvi zvinoita kuti ive imwe yenzizi diki pane dzese.
Ndinovimba kuti neruzivo urwu unogona kudzidza zvakawanda nezverwizi rweAmazon.