Njengoko sisazi, imvula yinto exhaphakileyo yemozulu kwiplanethi yethu. Ayikho enye into njengokuwa kwamasuntswana amanzi kwifom engamanzi, imveliso yokuncipha kunye nokupholisa umphunga wamanzi emafini phezulu kwetroposphere. Ngamanye amaxesha siyithiya imvula ngegama lemvula, nangona oku kubhekisa kudidi olubanzi kakhulu. Ukuveliswa kwemvula kuxhomekeke kwizinto ezininzi: iqondo lobushushu, uxinzelelo lomoya kunye nokufuma. Inkqubo ye- Iimvula ezinkulu zezo zenzeka ngamandla amakhulu kwaye okwexeshana. Ininzi imibuzo malunga noluhlobo lwemvula nokuba ingaqala njani.
Ke ngoko, siza kulinikela eli nqaku ukuze likuxelele yonke into ekufuneka uyazi malunga nezikhukula zemvula, iimpawu zazo kunye nendlela ezenzeka ngayo.
Imvelaphi yemvula
Ukuze sazi iimpawu nemvelaphi yeemvula ezinkulu, kufuneka siqonde indlela eqala ngayo imvula. Imvula ayikho enye into eyinxalenye yomjikelo wamanzi apho amathontsi amanzi atsibayo kwaye ngaphambili ayenziwe elwandle, imilambo, amachibi kunye nomhlaba apho kukho amanzi.
Imvula yenzeka phakathi kweentlobo ezahlukeneyo Iindidi zamafu afana necumuloninbus kunye nimbostratus. La ngamafu afumana ubuninzi bokufuma okusuka emoyeni. Xa umphunga wamanzi unyuka kwaye ufikelela kubude, zihlala ziyimimandla ebandayo. Oku kubangela ukuba umphunga udibane kwaye amathontsi amanzi enze umbulelo kwi-hygroscopic condensation nuclei. Le nuclei yempembelelo inokuba luthuli okanye amasuntswana amisiweyo afumaneka emoyeni. Xa zixinana zifikelela kubunzima obugqibela ngokuthintela isenzo somxhuzulane.
Ukuvela kwemvula kunokubakho ngeendlela ezintathu:
- Imvula yokuhambisa: zezo ntlobo zemvula apho umoya oshushu udibana nomphezulu womhlaba kwaye ufudunyezwe sisenzo selanga. Nje ukuba inyuke emoyeni, iyaphola kwaye imvula iyenzeka ngenxa yokuxinana kwamathontsi amanzi.
- Iimvula ze-Orographic: zezo zenziwa xa ubunzima bomoya ofumileyo bungqubana nentuthuzelo yentaba. Lo moya uthambekele ekunyukeni kwethambeka ukhuphe konke ukufuma kwawo de wehle wome ngokupheleleyo kwelinye icala lentaba.
- Iishawari zangaphambili: Ziveliswa kukungqubana kwezihlunu zomoya ezifumileyo ezinobushushu obahlukeneyo. Ngokwesiqhelo ihlala ikhwalithi enye kwaye enye ibanda. Ezi mvula zihlala zinesitshingitshane okanye uhlobo lwenkanyamba.
- Iimvula ezinkulu: zenziwa ngokwahluka kwamaqondo obushushu kunye nomphezulu womhlaba. Ihlala isenzeka ekupheleni kwehlobo kwaye zizivuthuvuthu ezinamandla amakhulu adla ngokwenza umonakalo omkhulu, ngakumbi kwezolimo.
Ukuyilwa kweemvula ezinkulu
Abantu abaninzi bayazibuza ukuba kutheni izantyalantyala zemvula zingena ngasekupheleni kwehlobo. Kuqhelekile ukuba kwiintsuku zokugqibela zika-Agasti kukho isaqhwithi kwindawo elungileyo yelizwe lethu. Kwaye kukuba imvelaphi yale mvula ibangelwa kukungazinzi. Ukungazinzi kuhlala kugxile kumazantsi mpuma usingasiqithi ngemvula eninzi kakhulu engaphezulu kwama-200 mm.
Ezi ziqendu zeemvula ezinamandla zihlala zaziwa ngokudibeneyo njengethontsi elibandayo. Inesizungu phantse minyaka le kwindawo engqonge uLwandle lweMeditera ngeli xesha. Zihlala zahluka phakathi kweentsuku zokugqibela zika-Agasti kunye neeveki zokuqala zika-Okthobha. Ngokwesiqhelo inyanga kaSeptemba yeyona inokwenzeka ekwakhiweni kwabo. Zonke ezi nkqwithela zinzima zenzeka rhoqo ngomhla ofanayo azingqinelani, kodwa zibhekisa kwizinto ezithile zemozulu.
Esona sizathu sokuvela kweemvula ezinkulu ngumahluko kumaqondo obushushu. Esinye sezizathu eziphambili kukuba amaqondo obushushu aphezulu oLwandle lweMeditera ekupheleni kwehlobo ayaphikisana nemihla yommandla wosingasiqithi. Ekupheleni kwehlobo amaqondo obushushu oLwandle lweMeditera ajikeleze iidigri ezingama-27, nangona kukho iirekhodi zobushushu eziye zafikelela kuma-31.
Kwelinye icala, kufuneka sithathele ingqalelo ukuba ihlobo lelona xesha lizinzile kakhulu elizweni lethu. Utyelelo loqhwithela kwiinyanga zasehlotyeni aluqhelekanga kakhulu. Nangona kunjalo, ekupheleni kweli xesha izivunguvungu zenyakatho ye-hemisphere ziqala ukuvuka kwaye ziza ngenyanga kaSeptemba.
I-DANA ibangela ukuba izantyalantyala zemvula zenze
Xa sibhekisa kwi-DANA oko kuthetha ukuba uxinzelelo lodwa kumanqanaba aphezulu. Oku kulingana nento esiqhele ukuyibiza ngokuba yipokotho yomoya obandayo ukuphakama. Xa olu xinzelelo kubude buqukethe umoya obandayo kakhulu kumanqanaba aphezulu omoya kodwa ngaphandle kwegalelo lomoya obandayo ngaphezulu, Ime kwindawo ekufuphi yoLwandle lweMeditera. Kuba sinamaqondo obushushu aphezulu apha, kungale mihla, sinomahluko omkhulu kumaqondo obushushu phakathi kwezahlulo ezahlukeneyo zomoya.
Lo mahluko weqondo lobushushu uphawula ukungazinzi komoya apho sibona ukuba iziqwenga zomoya ziphakama ngokukhululeka okukhulu, zikhawuleze zizaliswe ngumphunga wamanzi xa ziqubisana nomoya obandayo kwaye zibangele izaqhwithi ezinamandla. Njengoko sisazi, xa umoya oshushu unyukela kwicala eliphezulu le-atmosfera sifumana ukungxama ngokukhawuleza kwamathontsi amanzi. Ukuba le condensation yenzeka ngesantya esiphezulu, isaqhwithi siya kuba nogonyamelo olungaphezulu.
Ukongeza koku sele sithethile, ukuba olu xinzelelo kubude lufezekisiwe lubekwe kwindawo elungileyo kwaye lufikelela kwigalelo lomoya elivela kweli candelo, ukuba sidibanisa into enoxanduva lokufumana isixa esikhulu sokufuma kuLwandle lweMeditera. Kubangelwe imeko ekhethekileyo yemvula enkulu. Ziyimvula ezinokudlula i-300 mm. Kukho irekhodi elacwangciswa ngo-1987 kwingingqi ye ILa Safor eneemvula ezingama-500 mm ezibangelwa zizantyalantyala zemvula.
Ndiyathemba ukuba ngolu lwazi ungafunda ngakumbi malunga nezantyalantyala zemvula.