kogin wani mashigin ruwa ne na dabi'a, yawanci rafi ne mai ruwa mai dadi , yana gudana a sama ko cikin kogo zuwa wani ruwa a kasa mai tsayi kamar teku , teku , bay , tabki , dausayi , ko wani kogi. A wasu lokuta, kogi yana gudana cikin ?asa ko ya bushe a ?arshen tafiyarsa ba tare da isa wani ruwa ba. Ana iya kiran ?ananan koguna da sunaye kamar rafi , rafi , da rivulet . Babu wasu ma'anoni a hukumance na jimlar kalmar kogi kamar yadda aka yi amfani da su ga fasalin yanayin ?asa , ko da yake a wasu ?asashe ko al'ummomi, ana bayyana rafi da girmansa. Yawancin sunaye na ?ananan koguna sun ke?anta da wurin yanki; Misalai sune "gudu" a wasu sassan Amurka , " kuna " a Scotland da Arewa maso Gabashin Ingila , da "beck" a Arewacin Ingila . Wani lokaci ana siffanta kogin da ya fi kogi girma, amma ba koyaushe ba; harshen ba shi da tabbasko

Koguna muhimmin bangare ne na zagayowar ruwa . Ruwa daga magudanar ruwa gaba?aya yana tattarawa cikin kogi ta hanyar ruwan sama daga hazo, ruwan narkewar da ake fitarwa daga kankara da fakitin dusar ?an?ara, da sauran hanyoyin ?ar?ashin ?asa kamar ruwa na ?asa da ma?u??ugan ruwa . Ana la'akari da koguna sau da yawa manyan siffofi a cikin wuri mai fa?i; duk da haka, a zahiri suna rufe kusan kashi 0.1% na ?asar a Duniya. Har ila yau, koguna ne mai muhimmanci na halitta terraformer, kamar yadda erosive mataki na Gudun ruwa sassa?a fitar da rills, gullies , da kwaruruka a cikin surface kazalika da canja wurin silt da narkar da ma'adanai a kasa, kafa kogin deltas da tsibirai inda kwarara ya ragu. A matsayin ruwa, koguna kuma suna yin ayyuka masu mahimmanci na muhalli ta hanyar samarwa da ciyar da wuraren zama na ruwa don ruwa da namun ruwa da flora, musamman ga nau'in kifin da ke ?aura, tare da ba da damar yanayin yanayin ?asa don bun?asa a cikin yankunan magudanan ruwa .

Koguna suna da mahimmanci ga ?an adam tunda yawancin ?auyuka da wayewar mutane an gina su a kusa da manyan koguna da koguna. Yawancin manyan biranen duniya suna kan gabar koguna, kamar yadda suke (ko kuma) sun dogara ne a matsayin tushen ruwa mai mahimmanci, don samar da abinci ta hanyar kamun kifi da ban ruwa, don jigilar kaya, azaman iyakoki na halitta da/ ko wuraren kariya, a matsayin tushen samar da wutar lantarki don tuka injina ko samar da wutar lantarki, don wanka, da kuma hanyar zubar da shara . A zamanin kafin masana'antu, manyan koguna sun kasance babban cikas ga zirga-zirgar mutane, kayayyaki, da sojoji a yankuna. Garuruwa sukan bun?asa a ?an wuraren da suka dace da titin mota, gina gadoji, ko tashoshin jiragen ruwa ; manyan biranen da yawa, irin su Landan , suna a mafi ?an?anta kuma mafi aminci wuraren da za a iya ketare kogi ta gadoji ko jiragen ruwa . ^[1]

A fannonin kimiyyar duniya , ilmin dankalin turawa shine binciken kimiyya na koguna, yayin da ilimin ilimin ilimin kimiyyar ilimin halittu shine nazarin ruwa na cikin ?asa gaba?aya.

Tushen da magudanar ruwa [ gyara sashe | gyara masomin ]

Kogin yana farawa ne daga wani tushe (ko mafi yawan ma?u??uka da yawa) wanda yawanci magudanar ruwa ne, yana magudanar da duk rafukan da ke cikin magudanar ruwa, ya bi magudanar ruwa, ya ?are ko dai a baki ko baki wanda zai iya zama ha?uwa, kogin delta , da dai sauransu. . Ruwan da ke cikin kogi yawanci yana iyakance ne a tashar tashoshi, an yi shi da gadon rafi tsakanin bankunan . A cikin manyan koguna, galibi ana samun faffadar ambaliya mai siffa ta hanyar ambaliya sama da tasha. Ambaliyar ruwa na iya zama mai fa?i sosai dangane da girman tashar kogin. Wannan bambance-bambancen da ke tsakanin tashar kogi da filin ambaliya na iya zama duhu, musamman a cikin biranen da filayen kogin na iya bunkasa sosai ta hanyar gidaje da masana'antu.

Ma'anar " harbe " da " ?asa " suna nufin alkibla zuwa tushen kogin da kuma bakin kogin, bi da bi.

Tashoshi [ gyara sashe | gyara masomin ]

1. ↑ see for example John Speed's atlas 'The Theatre of the Empire of Great Britaine' published in 1611 and 1612 and the UK 'Old Series' of Ordnance Survey maps (1817?1830)