Rainfall (Maize)									Xhosa

Isimbo semvula nokuqhuma komphunga wamanzi



Imiyalelo: 

Folio strap: Ukongezelelwa kwexabiso

Byline: Ulwazi lufunyenwe kwiMveliso yoMbona phantsi kwencwadi yoqeqesho ngokunkcenkcesha

Photos: Isazobe 1.1: Imvula yonyaka yesixa esiqhelekileyo ilinganiswa ngokwe-mm ngonyaka.

 Isazobe 1.2: Isixa sonyaka esiqhelekileyo sokuqhuma komphunga wamanzi silinganiswa ngokwe-mm ngonyaka.



Ukufuma ngowona mba ubalulekileyo ophembelela umsebenzi wokuvelisa izityalo. Ummandla ngamnye unesixa esiqhelekileyo semvula esifakwe exwebhini. Le mvula yesiqhelo yiyo enika isalathiso esithembeke kakhulu sokuba zeziphi izityalo ezinokulinywa kummandla othile phantsi kweemeko zomhlaba owomileyo / owondliwa ngemvula. Apho kunokwenzeka khona ukunkcenkcesha, ikhona eminye imibandela yemozulu ebaluleke ngakumbi njengoko iimfuneko zamanzi zinokulawulwa ngokunkcenkcesha.

Kufuneka kukhunjulwe ukuba nangona imvula inokuna, asingawo onke loo manzi afunekayo kwisityalo. Ukuba imvula ina ngamandla amakhulu, amanzi aqengqelekayo ayanda. Ukuba umhlaba unethambeka, ngokunjalo amanzi aqengqelekayo ayanda. Kuxhomekeke kwindlela osetyenzwa ngayo umhlaba, umhlaba usenokuba nomaleko ogangathekileyo oza kuthintela ukufunxeka kwawo. Ukuba umhlaba awunasigcina-kufuma kuyanda ukuqhuma kwamanzi njengomphunga. Uhlobo lomhlaba nalo luphembelela ubungakanani bokufuma obunokugcinwa emhlabeni kanti ubukho bokhula emhlabeni nako kunokusebenzisa ukufuma okusemhlabeni, ukuze izityalo zingakufumani. Isixa sonyaka sesiqhelo semvula nesokuqhuma kwamanzi njengomphunga eMzantsi Afrika siboniswa kwisazobe 1.1 nakwisazobe 1.2 (DWAF, 1986).

Unganeno kuma-20% umhlaba waseMzantsi Afrika oyi-1,05 sezigidi zee-square kilometre onemozulu ephantse yafuma nenemvula yesixa sesiqhelo engaphezu kwama-750 mm/ngonyaka nesixa sesiqhelo sokuqhuma kwamanzi njengomphunga esinganeno kwi-1 400 mm/ngonyaka – esinokulindelwa njengeemeko ezilungele ukulinywa kwezityalo nokuveliswa kwezityalo. 

Imimandla enemvula engaphezulu kuma-500 mm/ngonyaka kunye nokuqhuma kwamanzi njengomphunga okunganeno kwi-1 800 mm/ngonyaka kubandakanya ummandla osembindini we-highveld, ummandla oselunxwemeni olusempuma kunye nommandla wemvula yasebusika. Ukunkcenkcesha iintlobo-ntlobo ezibanzi zezityalo, ngokunjalo nokulinywa komhlaba owomileyo ubukhulu becala kulinywa umbona, ummoba nengqolowa kukholisa ukwenzeka kule mimandla. Ubukhulu belizwe bunemozulu efudumeleyo nephantse ukoma ukuya kweyomileyo, nemvula yesiqhelo, enika nganeno kwama-50% kokuqhuma-kumfimfa kwamanzi okufunwa zizityalo ukuze zikhule kangangoko ukwenzela imveliso. Ukunkcenkcesha ke ngoko kubalulekile kumadlelo, kwigadi yeziqhamo nasekulinyweni kwezityalo kule mimandla.





Isazobe 1.1: Imvula yesiqhelo yonyaka ilinganiswa ngokwe-mm/ngonyaka





Figure 1.2: Ukuqhuma kwamanzi njengomphunga kwesiqhelo ngonyaka kulinganiswa ngokwe-mm/ngonyaka



