Ulwandlekazi

**Ulwandlekazi** yindikimba yamanzi anetswayi ehlanganisa cishe amaphesenti angama-70.8% woMhlaba. Ulwandle luhlukaniswe lwaba izindikimba zamanzi ezinkulu, ezibuye zibizwe ngokuthi *izilwandlekazi* ( iPacific, i-Atlantic, i-Indian, i- Antarctic/ iNingizimu, ne- Arctic Ocean ) ,  futhi zona ngokwazo zihlukene kakhulu zaba ulwandle, gulfs kanye nezindikimba zamanzi ezilandelayo . Ulwandle luqukethe amaphesenti angama-97% wamanzi oMhlaba  futhi luyisigcoyi esiyinhloko samanzimbulunga womhlaba, lusebenza njengenqolobane yokushisa egcina isidlakalasi somhlaba , kanye nomjikelezo wawo womCalahle nomjikelezo wamanzi, okwakha isisekelo sezulu nesimo sezulu emhlabeni jikelele. Ulwandlekazi lubalulekile kwimpilo eseMhlabeni, luphethe izilwane eziningi zomhlaba kanye nempilo ye -ngunaza,  okuyimvelaphi yomdibakhanya futhi ngalokho-ke isOhwe somoyambulunga woMhlaba, sihlinzeka ingxenye yawo.

Amanzi olwandle aqukethe uhowo oluncibilikileyo, oluhlanganisa IsOhwe, UmCalahle ontuhlambili, kanye neNihwe. Kukhona ukwenanana kohowo okwenzeka ebusweni bezilwandlekazi. Ubuncibiliki baloluhowo buncike kumazinga wokushisa kanye nobutswayi bamanzi. Ukukhuphuka komCalahle ontuhlambili kumoyambulunga woMhlaba, kuyanda ngenxa yokuphafuzwa kwe- CO2 , okubangwa ukushisa kwesivamelo sezintshicwa. Lapho izilwandlekazi zimunyunga lo- CO2 kusuka kumoyambulanga, kuba nokuqoqeleka kwamanani aphezulu aholela ekuphenduleni izilwandlekazi zibe yisimunyu, okwehlisa isizima sodliki leHwanzi .

Ulwandlekazi lunezinzuzo eziningi kubantu ezifana nezinkonzo zempilandawonye, ukufinyelela ekudleni kwasolwandle, kanye nensiza yezokuthutha. Ulwandlekazi lwaziwa ngokuba ikhaya lemiqhinqa engaba yizi-230,000, futhi kungenzeka mingi kunalesibalo  – mhlampe elimiqhinqa engaphezu kwezigidi ezimbili. Nakuba kunjalo, ulwandlekazi lubhekene, nezinsongo ezingokwemvelo eziningi, ezifana nomnukubalo wolwandle, ukudoba ngokweqile, Kanye nokukhahlanyezwa ukuguquguquka kwezulu.  Lokhu kukhinyabezeka kuhlanganisa ukufudumala kolwandlekazi, ukumunyuzeka kolwandlekazi nokukhuphuka kwesihlelembo solwandle.

## uMsukagama

### Ulwandlekazi nolwandle

Amagama athi "ulwandlekazi" nelithi "ulwandle" asho izindikimba zamanzi ezingafani ezimboze uMhlaba. NgesiZulu esivamile lonke udwadwakazi lamanzi sithi *ulwandle*,  sisho sihlanganisa izilwandlekazi iPacific, iAtlantic, i-Indian, i-Antarctic, kanye ne-Arctic. Zonke lezi zilwandlekazi sibuye sizibize ngokuthi ulwandle, kuyinjwayelo ukuwaphambanisa.

Kodwa uma sesihlukanisa kahle ukwabiwa kwamagana, "ulwandle" alulingani nolwandlekazi, njengoba ulwandle kuyindikimba yamanzi engungwe yizwe ngokuphelele noma ngokwengxenye, njengolwandle iMedithera. Ulwandle igama elibuye lisho udwadwakazi oluncane lamanzi njengolwandle oluBomvu *(Red sea)* noma ulwandle laseNyakatho *(North sea)*. Izilwandle zincane kunezilwandlekazi.
uNyembezi uyawusekela lombono njengoba Isichazamazwi sakhe sithi *sea* - ulwandle, bese siqhubeka sithi *ocean* - ulwandlekazi. 

## Umlando wemvelo

### Imvelaphi yamanzi

Osonzululwazi bakholwa ukuthi udwadwakazi lenani lamanzi lwaluyingxenye yoMhlaba kusuka ekubumbekeni kwawo. Imizwayi yamanzi kungenzeka yayiputshuka kalula emandleni womnyondo woMhlaba lapho ungkabi usaqala ukwakheka ungakabi namandla amakhulu.

Ekubumbekeni koMhlaba, usaseyisicaba sothuli, kungenzeka ukuthi uMhlaba wawunezilwandlekazi ze-magma. Ngokomphumela, ukuhwamuka kohowo, ubuqhebeqhebe entshabamlilo, ukugadlaza kwamaqhumanyezi, kwakhiqiza umoyambulunga wokuqala womCalahle ontuhlambili, iNihwe, nomhwamuko wamanzi, ngokwemichachiso yakamuva.
Uhowo nomoyambulunga kukholwa ukuba kwanqwabelana ezigidini zeminyka edlule. Ngemuva kokuphola kobuso bomhlaba, umhwamuko wamanzi wajiyeka emva kwesikhathi, kwase kube izilwandlekazi zokuqala zoMhlaba. Kungezneka ukuthi izilwandlekazi zokuqala zazishisa kunezanamuhla, futhi zazinombala oluhlaza ngenxa yokugcwala kwensimbi.

Ubufakazi besimomhlaba busilekelela ukuba sithole inkathi yokuvela kwamanzi aluketshezi eMhlabeni.  Uqweqwe lwetshenso olwatholakala e-Isua Greenstone Belt lusinika ubufakazi bokuthi amanzi ayekhona eminyakeni eyizigidinqindi ezi-3.8 ezidlule. Uma izilwandlekazi zazikhona kuleyo minyaka, kusamle kusadingek obunye ubufakazi obuzofakazela obukhona.
Kamuva, ngo-August wezi-2020, abacwaningi babika ukuthi ayehlezi ekhona amanzi angagcwalisa izilwandlekazi zoMhlaba kusukela ekubumbekeni kwawo. Kulolu nongo olusha, uhowo lomoyambulunga yilona olwagcina izilwandlekazi ukuba zingaqandeki lapho ilanga elisanda kubumbeka lingwangwanza ngamaphesentu angama-70.

### Ukwakheka kwezilwandlekazi
Imvelaphi yezilwandlekazi zoMhlaba ayikacaci kakhle.

Ezokuzabazaba, nokukhuphuka kolwandle kuyaqhubeka nokuguqula uthungulu nokwakheka kwezilwandlekazi. Kodwa kungenzeka ulwandlekazi yinto kudala ikhona eMhlabeni, izigidi zeminyaka.

Selokhu lwabumbeka, ulwandlekazi zilubhekene nezimo eziningi lwaba nomumo oluhlukahlukene, kwezinye izikhathi lumboza imbulunga yonke.

Izinkathini zesimo sezulu esimakhaza, kwakuba namaqeqeba eqhwa amaningi, futhi amanzi wembulunga yonke ayeqogelelana kube yiqhwaukuze angabi maningi kweinye izinngxenye zomhlaba.

## Amaphathelelo