Ho na le mekgwa e meraro ya ho kgelella metsi a pula. Macro-catchment ke pokeletso ya metsi a pula a phallang kantle ho polasi. Micro-catchment ke pokelletso ya metsi a pula a phallang kahara polasi, ha rooftop micro-catchment, e le pokelletso ya metsi a pula a tswang marulelong a meaho.
Macro-Catchment
Ho bokellwa metsi a pula ho tloha dibakeng tse pota-potileng polasi kapa ploto. Metsi a ka fokotswa lebelo mme a tsamaiswa methating e kang jessours e sebediswang Tunisia. Methati ena e fumanwa metheōng e tebileng haholo moo dipula tsa selemo le selemo di nang ka botebo ba 100-200 mm. Metsi ana a pula a bokellanang a ka eketsa metsi hore a fihle ho pula ya 400 mm- 500 mm ka selemo. Marako a majwe a bopang merifi/dijana kapa matamo a sa tebang hammoho le lekgalo le tsamaisang metsi a phophomang, ke tse ding tsa dikarolo tse supang mokgwa wa pokello ya metsi ya macro-catchment. Metsi a mang a phophomang a ka bolokwa. Melemo e meng e kenyeletsa ho tsosoloswa ha metsi mpeng ya lefatshe le taolo ya dikgohola.
Micro-Catchment
Ho bokellwa metsi a pula ho tloha sebakeng seo mobu o phetholwang teng le dibakeng tse etseditsweng ho bokella metsi. Ha e le hantle, sena se etswa ka ho bopa merifi e sa tebang le dikotjana metheōng hore ho bokellwe metsi.Metsi oohle a bolokwa mobung. Tsamaiso ena e fokotsa phallo ya metsi ho tloha masimong mme e thibela kgoholeho ya mobu.
Micro-Catchment Marulelong
Ho bokellwa metsi a pula ho tloha marulelong mme a kenngwa motjheng ka dipeipi ho kena kahara setshelo. Hangata ho sebediswa pompo e hoketsweng tankeng. Metsi a fumaneha hanghang ho ka sebediswa ka lapeng.
Mokgwa o Hlwahlwa ka ho Fetisisa wa ho Bokella Metsi a Pula
Mokgwa wa ho bokelletsa metsi a pula o bitswang (IRWH) o ile wa thehwa ke bafuputsi ba Setsi sa Lekgotla la Dipatlisiso tsa Temo bakeng sa Mobu, Boemo ba lehodimo le Metsi, motseng wa Bloemfontein.
Mokgwa wa IRWH o sebetsa ka ho betla metjha e mmedi ya bophara ba 2 m e pakeng tsa mela e mmedi ya dijalo e mabapi mme ho bolokwa metsi a phallang kahara dikotjana kapa matamo a mannyane a sa tebang. Kamora hoba merifi ena e ahwe, ha ho a lokela ho lengwa kapa ho phetholwa mobu-ho hlaolelwa le ho phetholwa ha mobu-ho etswa moo metsi a phallang teng mme ho tla ba le mokokotlo oo e leng oona o matlafatsang ho phalla ha metsi. Metsi a bokelletsweng ka tsela ena a ka kenella botebong ba mobu, kahoo hona ho ka fokotsa mouwane.
Mokgwa o na wa ho bokelletsa metsi a pula, o kopanya mekgwa ya temo ya ho kgelella metsi, ho sa phethole mobu, ho phetholwa ha mobu kahara merifi ya metsi le ho kwahela mobu o letsopa le ka bang kotsing ya komello. Ho phetholwa ha mobu kahara merifi ena, ho bolela hore mobu o sebakeng seo metsi a bokeletswang teng, mohl. Matamo a sa tebang, o a qhalakanngwa o be bobebe. Sena se ka etswa ka haraka mme ho tla netefatsa hore metsi a monyela mobung.
Mokgwa ona wa IRWH o ka fokotsa phallo ya metsi ka hohle-hohle le ho fokotsa mouwane hodima mobu. Sena se thusa ho eketsa tjhai qetellong hobane metsi a a eketseha pela metso ya semela.
Dipatlisiso tse entsweng Thaba Nchu, profenseng ya Free State, di supile hore mokgwa ona wa IRWH o ekeditse tjhai ya lehlabula: poone e eketsehile ka 40%, soneblomo ka 30% le dinawa tse omisitsweng ka 90%.
Ho kgothaletswa hore o kwahele moo metsi a phallang ho thibela kgoholeho ya mobu.
Melemo ya Metsi a Phallang Kahara Masimo
Melemo ya metsi a merifi:
E thibela ho phalla ha metsi kahara masimo
E eketsa ho kenella ha metsi mobung
E boloka metsi a kgelelletsweng mobung
Ho sireletsa mobu ka lera ho fokotsa mouwane
Melemo ya sebaka sa ho phalla ha metsi:
E ntlafatsa phallo ya metsi kahara masimo
E sebetsa e le sebaka se sa bobedi sa polokelo ya metsi
Tshebediso ya lera le sireletsang mobu moo metsi a phallang, e fokotsa mouwane mme e thibela kgoholeho ya mobu
Ditlhoko tsa ho Kgelella Metsi a Pula a Bokeletswang Masimong - IRWH
Ho kgelella metsi a pula ha ho a lokela mobu o lehlabathe mme ho loketse haholo mobu o letsopa kapa mobu a tswakehileng mefuta ya mobu ya mara a sa tshwaneng mme ho na le letsopa kahare. Ho tseba hore mobu wa letsopa o mokae, bopa seboko se sennyane ka mobu mme o bope o tshwane le tlhaku ya C.
Motheō ha o a lokela ho feta 8% mobung o sa hoholeheng, jwaloka lejweng mme pula ya selemo le selemo e be pakeng tsa 450 mm le 700 mm.
Translated by Maletsatsi Sejake