Isimo Samanzi

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Water if life Amanzi ayimpilo. Izigidi-gidi zeminyaka izinto eziyimpilo emhlabeni zincike emanzini ukuze zikwazi ukuqhubeka nokuphila. Lapho uNeil Armstrong efika enyangeni ngo 1969, wachaza iPlanethi yoMhlaba njengendilinga eblu ezungeleza isibhakabhaka (i-space). Umbala oblu empeleni ukhombisa inani lamanzi akhona kwi-surface. I-surface yomhlaba engu 70% ingamanzi, kanti kuleli nani, cishe u 97% wawo, ngamanzi anosawoti, kanti yinani lika 3% nje kuphela elinamanzi afureshi. Kuleli nani lika 3%, elingaphansi kuka 1% lamanzi angaphilisa izinto emhlabeni, kanti inani eliseleyo litholakala njengo-ayisi kuma-poles Kodwa ngabe amanzi aphuma kuphi?

Amanzi esinawo emhlabeni madala kakhulu. Amanzi esiwasebenzisayo manje ake asetshenziswa zilwane zasemandulo zama-dinosaur kwiminyaka eyizigidigidi esazadlula. Lokhu kungoba umhlaba urisayikila amanzi futhi (recycles its water) lokhu kusho ukuthi amanzi abuye asetshenziswe futhi. Lokhu kusetshenziswa kwamanzi futhi kubizwa ngokuthi yi-water recycle. Amanzi akhona emhlabeni njengamaconsana atholakala kwizilwandle, imifula, amachibi, amadamu, kuma-swimming pool, umhlabathi nokunye. Umshiso welanga ubanga ukuthi amaconsana amanzi ashintshe ekubeni wokumanzi (ilikhwidi) abe yigesi (gas), ebizwa ngokuthi yi-vapour (umhwamuko). Lokhu kubizwa ngokuthi yi-evaporation. Umhwamuko wamanzi (water vapour) ubuse uyenyuka uya kwi-athimosfiya (utmosphere). Njengoba umhwamuko wamanzi (vapour) unyuka, uyaphola ebese ushintsha igesi (gas) ukuba yilikhwidi futhi, ebese ubuya uba ngamaconsana.

Lokhu kubizwa ngokuthi yi-condensation. Lapho la maconsana amanzi ekwi-athimosfiya (utmosphere), ayahlangana ukwenza amafu. Lapho la maconsana amanzi ebanzima ukuthi angahlala kwi-athimosfiya, ayawa anethe emhlabeni njengemvula, isichotho, iqhwa, nokunye. Lokhu kubizwa ngokuthi yi-precipitation (ukuncibilika). Amanye a la maconsana amanzi awela emalwandle, kanti amanye awela emifuleni nakwimifudlana, kanti amanye awela kumachibi namadamu, kanti amanye awela emhlabeni ebese ebuya emunceka futhi engena phansi noma ageleze njalo onqenqemeni aze ayongena emifuleni, kumachibi, amadamu noma kumalwandle. Amanzi awanamingcele, kanti njengoba egeleza kuyo yonke i-surface yomhlaba, asetshenziswa yizimila ezehlukene, izilwane kanye nabantu ukuze zikwazi ukuphila. La maconsana amanzi angabuye ashisiswe yilanga ebese futhi isimo serisayikili siyaphinda-phinda futhi.

Inani lamanzi emhlabeni lihlala linjalo kanti futhi ngeke lingezeleke noma liphunguleke, kodwa amanzi atholakala ngokungalingani kuwo wonke umhlaba. INingizimu Afrika ithola imvula elingana no 492 wamamilimitha ngonyaka kanti ezinye izindawo zomhlaba zithola imvula elingana u 985 wamamilimitha. Lokhu cishe uhafu wesilignaniso semvula yomhlaba. Kungakho iNingizimu Afrika ibekwa njengendawo eswele amanzi. Kanti kukhona nokuna kwemvula ngendlela engalingani kuyo yonke iNingizimu Afrika. Ingxenye esempumalanga imanzi uma iqhathaniswa nendawo esentshonalanga, ngenxa yesimo sezulu.

Isilinganiso semvula ngonyaka eMzansi Afrika

Distribution of mean annual rainfall in South Africa

INingizimu Afrika ibuye ibe nezimo zesomiso (droughts) kwezinye izikhathi, ebese kuthi kwezinye izikhathi kube nezikhukhula (floods), lokhu kuba nomthelela kwisimo samanzi kuyo yonke iNingiimu Afrika. Nangaphezu kwalokho, izimo zokoma zibangela ukuthi kubenezinga eliphezulu lomhwamuko (high evaporation rate). Ososayense babika ukuthi ngokuya kokwenyuka kwezinga lokushisa komhlaba (global warming), iNingizimu Afrika izoba nezikhathi ezimanzi kakhulu, kanti futhi ibuye ibe nezimo zokoma kakhulu, okuzokwenza ukuthi kube nokwenyuka kakhulu kwezimo zezikhukhula kanye nezomiso.

Isomiso Izikhukhula

Drought and
flood

Okwamanje, kukhona inani elikhulu lamadamu kuyo yonke iNingizimu Afrika, agcina la manzi abalulekile. Kukhona nezikimu eziningana zokudlulisa amanzi ziwasusa kwezinye izindawo ezikhongozela amanzi ziwahambisa ngezipompo, amapayipi kanye nemisele ukuya kwezinye izindawo ezikhongozela amanzi. IGauteng iphakelwa amanzi asuka kwizikhongozelo ze-Vaal Dam ezibandakanya umfula we-Vaal, umfula we-Wilge kanye nezinye izindawo zemingenelo yamanzi. Kukhona izikimu ezimbili zokudlulisa amanzi athelela izikhongozeli ze-Vaal Dam, okuyi-Lesotho Higlands Water Project ethola amanzi asuka ezintabeni zeLesotho kanye ne-Thukela-Vaal Water Transfer Scheme, ethola amanzi asuka eKwaZulu-Ntal, kanti agelezeliswa kwizikhongozeli ze-Vaal Dam lapho kunesidingo. Ngokuya kwaboMnyango wezaManzi nezeMvelo, isidingo samanzi siyokwedlula ukutholakala kwawo eGauteng ngonyaka ka 2013 kanti kuyo yonke iNingizimu Afrika lokhu kuyokwenzeka ngo 2025. INingizimu Afrika ngeke yakwazi ukwakha amanye amadamu kanye nezikimu zokudlulisa amanzi ngoba zibiza imali enkulu Kungakho kunesidingo esikhulu samanzi eNingizimu Afrika, kanti futhi njengoba inani labantu liya lenyuka, lokhu kwenyusa nesidingo sokuphila, esenza ukuthi kube nesidingo esiphezulu samanzi.

Ukusetshenziswa kwamanzi eNingizimu Afrika

Ukusetshenziselwa ezolimo (okubandakanya i-irrigation)	60%
Ukusetshenziselwa ezeMvelo	18%
Ukusetshenziswa emaDolobheni naseMakhaya	11.5%
Ukusetshenziselwa ezeziMayini neziMboni	10.5%

(Luvela kwi: Nature Divided Land Degradation in South Africa, Ashwell, A & Hoffman, T, 2001)

Ukusetshenziswa kwamanzi ezindlini

	Imindeni yeholo eliphansi	Imindeni yeholo eliphakathi-naphakathi neliphezulu
Amathoyilethi	73%	37%
Ukubhava namashawa	19%	32%
Imishini yokuwasha izimpahla	NA	17%
Okunye isib. ukupheka, ukugeza izitsha kanye nokuwasha izimpahla, ukuphuza, nokunye.	8%	14%

Imizi enezingadi

Ukwenza izingadi	46%
Okunye	54%

(Luvela kwi: Water – How is it used at home, HE Jacobs, LC Geustyn and BF Loubser, 2005)

Enye inkinga engezelela kulesi sidingo samanzi ikhwalithi yamanzi. Ikhwalithi yamanzi ichazwa njengamanzi aphephile, aphuzekayo, kanti futhi angasetshenziswa yiyo yonke into ephilayo emhlabeni. ENingizimu Afrika ukusweleka kwamanzi afreshi kuphungula nekhwalithi yamanzi ngenxa yokungcoliswa kwamanzi (increase in pollution), kanye nokoniwa kwezindawo ezikhongozela amanzi emifula okubangelwa yinani elikhulu labantu abayohlala emadolobheni, uqedwa kwamahlathi, ukwenziwa kwamadamu emifuleni, ukoniwa kwamixhaphozi, izimboni, izimayini, ezolimo ukusetshenziswa kwe-eneji kanye nokungcoliswa kwamanzi ngengozi (accidental water pollution). Njengoba inani labantu landa kakhulu, kubakhona nokwanda kokungcoliswa kwamanzi nomoya kanye nokoniwa kwezindawo ezikhongozela amanzi Njengoba inani labantu landa, kukhona nokwanda kokungcoliswa kwamanzi nomoya kanye nokoniwa kwezindawo ezikhongozela amanzi.