Indlela Yokubala Amathuba Emvula
Imvula ingenye yezinto ezivame ukubonwa ngesimo sezulu ngoba ithinta ngqo imisebenzi yansuku zonke, kusukela kwezolimo, ezokuthutha, ezokuvakasha, kuya ekuphathweni kwezikhukhula. Kodwa-ke, abantu abaningi basalinganisa "isibikezelo semvula" "nokuqiniseka kwemvula." Kodwa-ke, ku-meteorology yanamuhla, amathuba emvula avame ukuvezwa njengento engenzeka. Lesi sihloko sixoxa ngendlela yokubala amathuba emvula kalula, kusukela emiqondweni eyisisekelo kuya ezibonelweni zokubala ezilula ukuzilandela.
Ukuqonda ukuthi liyini ithuba lokuna kwemvula
Amathuba emvula avame ukubizwa ngokuthi amathuba emvula (PoP). Akuyona indlela yokulinganisa ukuthi imvula izoba nzima kangakanani, kodwa kunalokho amathuba okuthi imvula izoba khona endaweni ethile phakathi nesikhathi esithile (isb., amahora angu-6 noma amahora angu-24).
Isibonelo, uma ithi “amathuba emvula angu-70%,” kusho ukuthi kunethuba elingu-70% lokuthi lizokuna endaweni nesikhathi esibikezelwe (ngokuvamile kulinganiswa ngomkhawulo othile, isibonelo okungenani u-0,1 mm).
Kubalulekile ukuqaphela: amathuba emvula akulula ukuwaqonda ngaso sonke isikhathi ngenxa yokungaqiniseki kwedatha yesimo sezulu, ukuguquguquka kwesimo sezulu, kanye nokulinganiselwa kwamamodeli okubikezela. Kodwa-ke, ngokwezibalo, amathuba emvula angabalwa kusetshenziswa idatha yomlando kanye nemiphumela yemodeli yokubikezela.
Izindlela ezimbili ezivamile zokubala amathuba emvula
Empeleni, kunezindlela ezimbili ezivame ukusetshenziswa:
1. Indlela yezibalo esekelwe kudatha yomlando
Ukusebenzisa amarekhodi emvula edlule ukulinganisa amathuba emvula ngesikhathi esithile.
2. Ukubikezela (imodeli) kanye nezindlela zokuqoqana
Ukusebenzisa umphumela wemodeli yesimo sezulu (kufaka phakathi izimo eziningi/amalungu emodeli) ukubala amathuba emvula.
Kulesi sihloko, ukugxila okuyinhloko kuyindlela yokubala amathuba okuna kwemvula kusetshenziswa indlela yezibalo engenziwa yinoma ubani, bese kuphetha ngokubuka konke kwendlela yokwenza amamodeli.
Idatha edingekayo
Ukuze ubale amathuba okuna kwemvula ngokwezibalo, udinga:
– Idatha yemvula yansuku zonke/yehora evela eziteshini zemvula noma ezindaweni zemvula.
– Isikhathi sedatha eside ngokwanele (isib. iminyaka eyi-10-30 ukuze siqine kakhudlwana).
– Incazelo yegama elithi “imvula” esetshenzisiwe: umkhawulo omncane wemvula obhekwa njengemvula (isb. ≥ 0,1 mm/ngosuku noma ≥ 1 mm/ngosuku).
Lo mkhawulo ubalulekile ngoba "ukuna okuncane" kungabhalwa phansi njengemvula, kodwa ngezinjongo ezithile (isib. ezolimo), ungacabanga ukuthi lina kuphela uma lingaphezulu kuka-5 mm.
Indlela 1: Amathuba emvula ngenxa yokwenzeka kaningi (indlela elula)
Indlela eyisisekelo kakhulu ukubala imvamisa yemvula esikhathini esifanayo.
Ifomula
\[
P(\text{rain}) = \frac{\text{number of rain days}}{\text{total number of days}} \times 100\%
\]
Isibonelo
Ake sithi ufuna ukubala amathuba emvula ngoJanuwari ngokusekelwe kudatha yeminyaka eyi-10. Uqoqa inani eliphelele lezinsuku ngoJanuwari zeminyaka eyi-10:
– UJanuwari unezinsuku ezingu-31.
– Idatha iyonke = 31 × 10 = izinsuku ezingu-310.
– Kulezi zinsuku ezingu-310, izinsuku ezingu-217 zaqoshwa ngemvula engu-≥ 0,1 mm.
Ngakho-ke:
\[
P(\text{rain}) = \frac{217}{310} \izikhathi ezingu-100\% \cishe kube ngu-70\%
\]
Lokhu kusho ukuthi, ngokomlando, amathuba emvula ngosuku olungahleliwe ngoJanuwari angaba ngu-70% (kusetshenziswa umkhawulo ongu-0,1 mm).
Izinzuzo kanye nemikhawulo
– Izinzuzo: kulula kakhulu ukubala.
– Imikhawulo: ayicabangi izimo zomkhathi zanamuhla, icabanga kuphela ngezilinganiso zomlando.
Indlela 2: Amathuba emvula ngosuku oluthile (i-climatology yansuku zonke)
Uma ufuna ukucacisa kakhudlwana, ungabala amathuba emvula ngosuku oluthile, ake sithi mhla ziyi-10 kuNhlaba, usebenzisa idatha yomlando yalolo suku yeminyaka eminingi.
Isinyathelo
1. Thatha idatha yemvula yosuku olufanayo, isibonelo njalo ngomhlaka-10 Meyi iminyaka engama-20.
2. Bala ukuthi lina kangaki (≥ umkhawulo) ngalolo suku.
3. Hlukanisa ngenani leminyaka.
Ifomula
\[
P(\text{rain on date} d) = \frac{\text{number of years of rain on} d}{\text{number of years of data}} \times 100\%
\]
Isibonelo
Idatha yangoMeyi 10 yeminyaka engama-20:
– Imvula ephindwe ka-14 (≥ 1 mm).
– Iminyaka iyonke = 20.
\[
P = \frac{14}{20} \izikhathi ezingu-100\% = 70\%
\]
Le ndlela ivame ukubizwa ngokuthi indlela ye-climatology yansuku zonke. Ukuze wandise ukuzinza, ungandisa isikhathi, isibonelo, usebenzisa izinsuku ezingu-9 (Meyi 6-14) bese ulinganisa.
Indlela 3: Amathuba “emvula enkulu” asekelwe emkhawulweni othile
Amathuba angabalwa futhi ngezigaba zamandla, njengemvula enkulu. Indlela iyafana, kuphela umkhawulo oshintshayo.
Isibonelo, incazelo yemvula enkulu: ≥ 50 mm/ngosuku.
\[
P(\text{heavy rain}) = \frac{\text{number of days with rain ≥ 50 mm}}{\text{total number of days}} \times 100\%
\]
Isibonelo:
– Izinsuku eziphelele eminyakeni emi-5: 5 × 365 = izinsuku eziyi-1825 (unganaki iminyaka eqaqayo ukuze kube lula).
– Izinsuku zemvula ≥ 50 mm: izinsuku ezingu-36.
\[
P = \frac{36}{1825} \izikhathi ezingu-100\% \cishe kube ngu-2\%
\]
Nakuba lincane, leli nani liwusizo ekuhlaziyeni izingozi zezikhukhula, ekuhleleni amanzi, kanye nasekuxwayiseni kusenesikhathi.
Indlela 4: Amathuba asekelwe ezimweni zangaphambilini (i-Markov elula)
Imvula ivame ukulandela "iphethini yokuqhubeka": uma lina namuhla, kungenzeka kakhulu ukuthi lina kusasa kunokuba lina namuhla. Ungabala amathuba okushintsha okulula usebenzisa imiqondo kaMarkov.
Chaza izimo ezimbili:
– H = imvula (≥ umkhawulo)
– T = akukho mvula
Bala kusukela kudatha yomlando:
– \(P(H|H)\): ithuba lokuthi lizokuna kusasa uma lina namuhla.
– \(P(H|T)\): ithuba lokuthi lizokuna kusasa uma lingakuna namuhla.
Isibonelo
Kusukela kuma-pair ayi-1.000 alandelanayo ngosuku:
– izikhathi ezingu-400 lithi “kuyana namuhla.” Kulezo zikhathi ezingu-400, izikhathi ezingu-260 lizona kusasa.
\(P(H|H) = 260/400 = 65\%\)
– Izikhathi ezingu-600 “ngeke line namuhla.” Kulezo zikhathi ezingu-600, izikhathi ezingu-180 lizone kusasa.
\(P(H|T) = 180/600 = 30\%\)
Lokhu kuvumela ukuthi amathuba emvula kusasa alungiswe ngokusekelwe ezimweni zanamuhla. Kuseyinto elula, kodwa engokoqobo kakhulu kunesilinganiso senyanga.
Indlela 5: Amathuba avela eqoqweni lamamodeli esimo sezulu (umbono jikelele womkhuba wesimanje)
Ekubikezeleni kwesimo sezulu kwanamuhla, amathuba emvula avame ukubalwa kusukela ekubikezelweni kweqembu, okuyiqoqo lokulingisa amamodeli amaningi anezimo zokuqala ezahlukene. Isimiso sithi:
\[
P(\text{rain}) = \frac{\text{inani lamalungu eqembu elibikezela imvula}}{\text{inani lamalungu eqembu}} \izikhathi eziyi-100\%
\]
Isibonelo
Kunamalungu eqembu angu-20 endaweni yakini kusasa:
– Amalungu ayi-12 abikezele imvula engu-≥ 1 mm.
– Amalungu angu-8 abikezelwe <1 mm. \[ P = \frac{12}{20} \izikhathi 100\% = 60\% \] Le ndlela ibonisa ukungaqiniseki kwemodeli. Ngokuvamile, lapho usuku lokubikezela luqhubeka, amathuba amaningi avame "ukunwebeka" njengoba ukungaqiniseki kukhula. Amathiphu ezibalo ezinembile 1. Setha umkhawulo wemvula ofanele. Umkhawulo ongu-0,1 mm ufanelekela izincazelo zemvula yesimo sezulu; ngemiphumela, kungadingeka u-5–10 mm. 2. Sebenzisa idatha ende nehlanzekile. Idatha engekho noma izinsimbi zokulinganisa ezinephutha zingashintsha imiphumela. Yenza ukuhlolwa kwekhwalithi yedatha. 3. Cabanga ngesizini. Amathuba emvula enkathini eyomile kanye nenkathi yemvula ahluke kakhulu. Bala ngokwehlukana ngesizini noma ngenyanga. 4. Sebenzisa iwindi lesikhathi esihambayo. Ngezinsuku ezithile, iwindi lezinsuku ezingu-±3 kuya ku-±7 lingenza izilinganiso ziqine kakhudlwana. 5. Hlukanisa phakathi "kwamathuba emvula" kanye "nangaki mm." Izimpendulo zamathuba "zizona," hhayi "zizona imvula engakanani." Isiphetho Ukubala amathuba emvula ngokuyisisekelo kusekelwe emcabangweni olula: ukuqhathanisa inani lemicimbi yemvula nenani eliphelele lokubonwa. Ungabala amathuba emvula aphakathi kwanyanga zonke, amathuba ngosuku oluthile, amathuba emvula enkulu, noma ngisho namathuba emvula kusasa ngokusekelwe ezimweni zanamuhla. Emikhubeni yanamuhla, amathuba emvula avame ukubalwa kusukela eqoqweni lamamodeli esimo sezulu, elihlinzeka ngendlela engenzeka efanela kangcono isimo sezulu esiguquguqukayo. Uma ungathanda, ngingakusiza ukuthi udale ukubala kwesampula kusetshenziswa idatha ye-Excel/CSV (isb., idatha yemvula yansuku zonke evela ku-BMKG noma esiteshini sakho semvula), ephelele ngamafomula e-Excel noma izikripthi ze-Python ukuze kubalwe amathuba emvula ngenyanga, ngesizini, kanye nomkhawulo wokuqina ngakunye.
