Yawan jama'a
 Yawan jama'a | |
|---|---|
| Bayanai | |
| Ƙaramin ɓangare na | population size (en)  |
| Fuskar | yawan jama'a da population genetics (en) |
Yawan jama'a ko ƙarancin yawan jama'a shine yanayin yawan haihuwa don tashi sakamakon yawan haihuwa da ya gabata, koda bayan yawan haihuwa ya fadi, ko kuma akasin haka. Wannan yana faruwa ne saboda karuwar yawan haihuwa a yanzu yana haifar da karuwar yawan mata masu haihuwa kusan shekaru ashirin zuwa arba'in bayan haka, ma'ana yawan yawan jama'a yana raguwa sosai a bayan yawan haihuwa. Sanannun misalai sun haɗa da Echo Boom ƙaruwar yawan haihuwa yayin da jarirai suka kai shekarun renon yara da kuma karuwar yawan jama'ar kasar Sin a duk zamanin manufofin yaro daya daga 1979 har zuwa 2021.
yawan jama'a yana bayyana dalilin da ya sa yawan jama'a zai ci gaba da girma ko da yawan haihuwa ya ragu ko ya ci gaba da raguwa koda kuwa yawan haihuwa ya karu. Yawan jama'a yana faruwa ne saboda ba kawai yawan yara ga kowace mace ba ne ke ƙayyade yawan jama'a, har ma da yawan mata masu shekarun haihuwa. A ƙarshe, lokacin da yawan haihuwa ya kai yawan maye gurbin kuma yawan mata a cikin shekarun haihuwa ya daidaita, yawan jama'a ya sami daidaito kuma yawan jama'ar ya zo ƙarshe. An bayyana yawan jama'a a matsayin rabo na girman yawan jama'ar a wannan sabon matakin daidaituwa zuwa girman yawan jama-a na farko.[1]
Misali
[gyara sashe | gyara masomin]Ka ɗauka cewa yawan jama'a yana da ƙarni uku: Na farko mafi tsufa, na biyu haihuwar yara da na uku yara Bugu da ƙari ɗauka cewa wannan yawan yana da yawan haihuwa daidai da huɗu 4 Wato, kowane ƙarni ya ninka girman na baya sau biyu. Idan an saita yawan jama'ar ƙarni na farko a 100, na biyu shine 200, kuma na uku shine 400. Shafin da ke ƙasa yana nuna yawan jama'a na farko a jere na farko.
| Lokaci | Farawa 1 | Farawa 2 | Farawa 3 | Farawa 4 | Farawa 5 | Yawan jama'a | Yawan haihuwa na yanzu |
|---|---|---|---|---|---|---|---|
| 0 | 100 (tsohon) | 200 (mai amfani) | 400 (yara) | 700 | 4 | ||
| 1 | ya mutu | 200 (tsofaffi) | 400 (mai amfani) | 400 (yara) | 1000 | 2 | |
| 2 | ya mutu | ya mutu | 400 (tsohon) | 400 (mai amfani) | 400 (yara) | 1200 | 2 |
Lura na farko cewa ƙarni na biyu da na uku na yawan jama'a na farko kowannensu ya ninka girman na baya sau biyu. Adadin mutanen farko shine 700 = 100 + 200 + 400.
Sa'an nan ɗauka cewa a ƙarshen ƙarni na uku, haihuwa ya faɗi zuwa maye gurbin don sauƙi ɗauka cewa ya zama biyu. Yanzu ku ci gaba da yawan jama'a a cikin lokaci zuwa ƙarni na gaba, layi na biyu na jadawalin. Zamani na farko ya mutu, kuma sabon ƙarni, na huɗu, daidai yake da na uku saboda yanzu haihuwa shine maye gurbin. Maimaita wannan tsari don isa ƙarni na biyar layi na 3 a cikin jadawalin. Zamani na biyar ya sake daidaitawa da na huɗu kuma yanzu tsararraki uku na yawan jama'a sun yi daidai, kuma yawan jama'ar sun kai ga daidaito.
Yawan jama'a na farko ya karu daga 700 zuwa 1,200 duk da cewa haihuwa ya ragu daga hudu zuwa maye gurbin biyu a ƙarshen ƙarni na uku. Yawan jama'a ya kai yawan jama'a zuwa matakan da suka fi girma a cikin tsararraki biyu masu zuwa.
Lokacin da kasar Sin ta fara gabatar da manufofin yaro daya, ci gaban yawan jama'a ya ci gaba ba tare da la'akari ba. Kodayake yawan yaran da aka haifa ya ragu sosai, yawan matasa masu girma ya kasance mai mahimmanci. A shekara ta 1979 lokacin da manufofin yaro daya ya fara aiki, yawan mutanen da suka zama manya ya dogara ne akan yawan haihuwa a cikin shekarun 1950, ba 1979. A sakamakon haka, yawan jama'ar kasar Sin sun ci gaba da karuwa kamar yadda suka faru a cikin shekaru 20 da suka gabata. Yawan jama'ar kasar Sin ya ragu a karo na farko kawai a shekarar 2023.[2]
Ƙarin matakai zuwa ƙaruwar yawan jama'a
[gyara sashe | gyara masomin]Yawan jama'a yana tasiri ga yawan haihuwa da mutuwar nan take a cikin yawan jama'a wanda ke ƙayyade yawan ci gaban halitta. Koyaya, don yawan jama'a su sami cikakkiyar ƙarancin ci gaban halitta, abubuwa uku dole ne su faru.
1. Yawan haifuwa dole ne ya daidaita zuwa adadin maye gurbin ya kamata yawan haihuwar ya zama 1. Idan yawan haihuwa ya kasance mafi girma fiye da yawan maye gurbin, yawan jama'a zai ci gaba da girma.
2. Dole ne Yawan mace-mace ya daina raguwa, wato, dole ne ya kasance daidai.
3. A ƙarshe, tsarin shekaru dole ne ya daidaita da sabon yawan haihuwa da mutuwa. Wannan mataki na ƙarshe yana ɗaukar mafi tsawo don kammalawa.[3]
Sakamakon
[gyara sashe | gyara masomin]Yawan jama'a yana da tasiri ga manufofin yawan jama'a saboda dalilai da yawa.
1. Game da kasashe masu yawan haihuwa alal misali a kasashe masu tasowa, yawan jama'a mai kyau, ma'ana yawan jama'ar yana ƙaruwa, ya bayyana cewa waɗannan ƙasashe za su ci gaba da girma duk da raguwar yawan haihuwa.
2. Game da ƙasashe mafi ƙarancin haihuwa alal misali a Turai, ƙarancin yawan jama'a yana nuna cewa waɗannan ƙasashe na iya fuskantar raguwar yawan jama'ar koda kuwa suna ƙoƙarin ƙara yawan haihuwa zuwa sauyawa na 2.1. Misali, wasu ƙasashen Gabashin Turai suna nuna raguwar yawan jama'a koda kuwa yawan haihuwarsu ya dawo zuwa matakin maye gurbin. Yawan jama'a na iya zama mara kyau idan yawan haihuwa yana ƙarƙashin matakin maye gurbin na dogon lokaci.
3. Yawan jama'a ya nuna cewa maye gurbin matakin haihuwa ra'ayi ne na dogon lokaci maimakon alamar yawan jama'a na yanzu. Dangane da tsarin shekarun da ke akwai, yawan haihuwa na yara biyu ga kowace mace na iya dacewa da ci gaba ko raguwa na ɗan gajeren lokaci.[4]
Ƙididdiga
[gyara sashe | gyara masomin]
Don lissafin yawan jama'a ga yawan jama'ar A, an gina yawan jama'an da aka tsara wanda yawan haihuwa ga yawan jamaʼa A nan da nan ya zama matakin maye gurbin. A karkashin irin wannan yanayi, yawan jama'a zai ƙare a cikin yawan jama'ar da ba su da tushe, ba tare da canje-canje na shekara-shekara a cikin takamaiman shekarun ko kuma yawan jama'aa ba. Ana lissafin yawan jama'a ta hanyar raba wannan yawan jama'ar ƙarshe ta yawan jama'an farawa. Motsi, Ω, ana iya bayyana shi kamar haka:
A cikin wannan daidaitattun, b shine yawan haihuwa yayin da eo shine tsawon rayuwa a lokacin haihuwa. Q shine jimlar yawan haihuwa ta hanyar haihuwa ta farko.
Ana amfani da wannan daidaitattun don samun Q dukkanin haihuwa ta hanyar haihuwa ta farko), r shine yawan ci gaba kuma μ shine yawan jama'a da ba su canza ba a lokacin haihuwa. Ro shine Net Reproduction Rate na yawan mutanen da ba sa canzawa.[5]
Dalilan da suka haifar
[gyara sashe | gyara masomin]Yawan jama'a yawanci yana haifar da canji a cikin Canjin yawan jama'a na ƙasar.[1] Lokacin da Yawan mace-mace ya ragu, matasa suna rayuwa tun suna yara kuma yawan tsofaffi suna rayuwa tsawon lokaci. Yawan haihuwa ya kasance mai girma, yana haifar da yawan jama'a gaba ɗaya ya karu. Dangane da yawan jama'a, koda kuwa an maye gurbin yawan haihuwa nan da nan tare da yawan haihuwa na maye gurbin, yawan jama'ar za su ci gaba da girma saboda yawan mutanen da suka riga sun shiga shekarun haihuwa.[1]
Dubi kuma
[gyara sashe | gyara masomin]- Demography - Nazarin yawan mutane da tsarin su
- Human overpopulation - Yanayin da yawan mutane ya wuce karfin muhalli
- List of population concern organizations
- Population stabilization - Yawan jama'a ba ya ƙaruwa ko raguwaShafuka da ke nuna taƙaitaccen bayanin manufofi
Manazarta
[gyara sashe | gyara masomin]- 1 2 3 Blue, Laura; Espenshade, Thomas J. (2011). "Population Momentum Across the Demographic Transition". Population and Development Review. 37 (4): 721–747. doi:10.1111/j.1728-4457.2011.00454.x. ISSN 0098-7921. PMC 3345894. PMID 22319771.
- ↑ Master, Farah; Master, Farah (17 January 2024). "China's population drops for second year, with record low birth rate". Reuters.
- ↑ Bongaarts, John (2009). "Human population growth and the demographic transition". Philosophical Transactions of the Royal Society B: Biological Sciences. 364 (1532): 2985–2990. doi:10.1098/rstb.2009.0137. ISSN 0962-8436. PMC 2781829. PMID 19770150.
- ↑ "The impact of population momentum on future population growth" (PDF). United Nations Dept of Economic and Social Affairs, Population Division. October 2017.
- ↑ Kim, Young J.; Schoen, Robert (1997-08-01). "Population momentum expresses population aging". Demography (in Turanci). 34 (3): 421–427. doi:10.2307/3038294. ISSN 0070-3370. JSTOR 3038294. PMID 9275250.