Yanayin Washington, DC

Washington, DC tana cikin yankin Mid-Atlantic na Amurka a 38°53′4 77°0 / 38.89500°N 77.03639°W / 38. 89500; -77.03639, daidaitattun Zero Milestone, akan Ellipse. A cewar Ofishin Ƙididdigar Amurka, birnin yana da yanki na murabba'in mil 68.3 (176.9 ), murabba'i mil 61.4 (159.0 km) wanda shine ƙasa, kuma sauran murabba'ir mil 6.9 (17.9 km2) (10.16%) wanda shine ruwa. Kogin Anacostia da karamin Rock Creek suna gudana cikin Kogin Potomac a Washington. 

Washington, D.C. tana kewaye da Arewacin Virginia a gefen kudu maso yamma da Maryland a kudu maso gabas, arewa maso gabas, da arewa maso yamma;  ya katse iyakokin da jihohin ke yi, wanda ke kudu da gabar kogin Potomac daga sama da kasa daga birnin.  Bangaren kogin Potomac wanda ya ratsa Washington, D.C. kusan yana cikin iyakar birnin, kamar yadda Washington, D.C. ya shimfida zuwa bankin kudu.  Birnin ya ƙunshi sauran gundumomi na tarayya, wanda a da yana cikin waɗannan jihohi biyun da ke makwabtaka da su kafin su ba da shi ga babban birnin ƙasar a shekarun 1790.  Ƙasar da aka ba da ita daga Virginia ta dawo da Majalisa a 1847, don haka abin da ya rage na gundumar zamani ya kasance wani ɓangare na Maryland.

## Yanayin ƙasa da ilimin ƙasa

Hoton hoto na Washington, DC yayi kama da yanayin yanayin ƙasa na yawancin Maryland.  Garin yana da manyan jikunan ruwa masu gudana guda uku: Kogin Potomac da magudanan ruwa guda biyu, Kogin Anacostia da Rock Creek.  Haɗin Potomac da Anacostia shine yanki mai tarihi wanda aka sani da Arsenal Point.  Gundumar kuma ta haɗa da Tashoshin Washington, wanda ke gudana zuwa mahadar kogin Anacostia da Potomac.  Akwai kuma tafkunan wucin gadi guda uku: Dalecarlia Reservoir, wanda ya ketare iyakar arewa maso yammacin gundumar daga Maryland, da McMillan Reservoir kusa da Jami'ar Howard, da Tafkin Georgetown a saman Georgetown.  Na huɗu, ƙaramin tafki yana a Fort Reno a Tenleytown.

Washington, D.C. tana cikin babban kwano.  Kasan kwano, inda fadar White House da Amurka Capitol suke, yana cikin mashigar mahadar kogin Anacostia da Potomac.  Fitowa daga filin ambaliya jerin filayen kogi ne masu tasowa.  Waɗannan manyan tudu sun kusa kewaye birnin.  Mafi girma daga cikin waɗannan filaye yana da ƙafa 200 sama da matakin teku kuma yana gaba da wani ɗorewa wanda ya shahara sosai a gefen gabashin kogin Anacostia.  Rawayoyi masu tsayi da ƙananan rafuka sun ratsa ta saman bene na gabas na Kogin Anacostia akai-akai akai-akai.  Ana iya samun misalan waɗannan kwaruruka masu rafi a Forts Dupont da Stanton 

Washington, DC tana kan layin faduwa, iyakar wurare biyu daban-daban na yanayin ƙasa ko larduna; dutse mai wuya na Piedmont Plateau zuwa arewa da yamma da kuma mai laushi na Atlantic Coastal Plain zuwa gabas. Filayen Piedmont yana arewa da yammacin birnin. Kwarin da aka yanke sosai da kuma shahararrun tuddai suna nuna wannan yanki.

Matsayi mafi girma a Washington, DC yana da ƙafa 410 (125 m) sama da matakin teku a Reno Reservoir a Tenleytown .  Matsayi mafi ƙasƙanci shine matakin teku, wanda ke faruwa tare da duk bakin tekun Anacostia da duk bakin Tekun Potomac ban da mafi girman mita 100 (yankin Little Falls-Chain Bridge). Matsayin teku a cikin Tidal Basin ya tashi da ƙafa goma sha ɗaya a lokacin Guguwar Isabel a ranar 18 ga Satumba, 2003. Cibiyar ƙasa ta Washington, DC tana kan shafin yanar gizon Hedikwatar kungiyar Amurka. Babban Birnin Amurka yana nuna haɗuwa da yankuna huɗu na gudanarwa na birnin.

Sauran shahararrun siffofin ƙasa na Washington, DC, sun haɗa da Tsibirin Theodore Roosevelt, Tsibirin Columbia, 'Yan'uwa mata Uku, da Hains Point.

Wasu yankuna, musamman a kusa da National Mall da sassa na Foggy Bottom, sun kasance marshes ko sassa na kogi da aka cika.

### Tarihin halitta
A cikin karni na 18, manyan sassan yankin sun kasance gandun daji, tare da nau'o'in da suka hada da zomo, turkey, pheasants, woodcocks, Turtles, da quail, da kuma nau'ikan tsuntsaye da yawa ciki har da mockingbirds, bluebirds, hummingbirds, da orioles. Sauran nau'o'in asali sun haɗa da maciji baƙar fata, maciji na garter, rattlesnake, jan ƙarfe, bullfrog da sauran nau'ikan kwari, Squirrels na ƙasa, Squirrels masu tashi, skunks, opossums, raccoons, foxes, beavers, deer, wolves, da bears. Snipes da nau'ikan Ducks daban-daban buns zaune a wuraren da ke da santsi, da kuma Soruses.

Nau'o'in bishiyoyi na asali sun haɗa da willow, birch, cedar, da oak. Sauran nau'ikan shuke-shuke da aka samo a gefen Potomac a farkon karni na 19 sun haɗa da jessamine mai launin rawaya, cactus mai laushi, farin horehound, fennel mai dadi, cherries na daji, da strawberries na daji. Babban kashi na wurin shakatawa yana ba da gudummawa ga babban bishiyar birane na 35% .

A shekara ta 1965, Shugaba Lyndon Johnson ya kira Kogin Potomac "abin kunya na kasa" kuma ya yi amfani da kogin don kwatanta bukatar Dokar Maido da Ruwa Mai Tsabtace ta 1966.  Kogin yanzu gida ne ga kamun kifi mai zafi da ruwa mai zafi kuma da ke haifar da gaggafa sun koma bakin kogin. Duk da yanayin birane mai zurfi, Gundumar Columbia cibiyar bincike ce kan kula da namun daji na birane, kula da nau'o'in mamayewa, maido da rafin birane, da kuma yanayin muhalli na raƙuman birane. Cibiyar Kula da Gidajen Kasa don Muhalli ta Birane ita ce tushen yanki na ƙwarewa da kimiyya mai amfani ga yankin.

### Girgizar ƙasa
Ayyukan girgizar ƙasa a Gundumar Columbia ba su da yawa. Babu girgizar kasa da ta kasance a cikin Gundumar, kuma babu wata kurakurai. Koyaya, ya ji girgizar ƙasa a Virginia, Maryland, da sauran jihohin da ke kewaye da shi da manyan girgizar kasa a Kanada da New England.

Gundumar ta ji girgizar asa na New Madrid a 1811-1812, kuma bisa ga tsoffin bayanan, mazauna sun "firgita sosai".  A cikin Maris 1828, Shugaba John Quincy Adams ya ji girgizar kasa "m" a Fadar White House kuma ya rubuta ta a cikin mujallarsa.  An ji girgizar kasa na Charleston a 1886 (ma'aunin girma 6.6 zuwa 7.3) a DC.  Girgizar kasa mafi karfi a Virginia ta faru a cikin 1897 kuma an ji ta a Gundumar.  Girgizar kasa a shekara ta 1925 a Kanada, wadda aka kiyasta kimanin girman 7, an ji ta sama da murabba'in mil miliyan 2 (kilomita 5.18).  Wata girgizar kasa mai karfin awo 6.2 a shekarar 1935 ta haddasa barna a birnin New York kuma ta girgiza mazauna yankin daga Maine zuwa Wisconsin..

An ji Girgizar ƙasa ta Virginia ta 2011 a Washington kuma ta haifar da lalacewar wuraren tarihi da abubuwan tunawa kamar Washington Monument da Washington National Cathedral.Washington, DC, tana cikin yankin yanayi mai zafi (Köppen climate classification: *Cfa*), tana nuna yanayi daban-daban guda huɗu. Yanayinta na musamman ne na Jihohin tsakiyar Atlantic. Gundumar tana cikin yankin tsayayyar shuka na USDA 8a kusa da gari, da kuma yankin 7b a wasu wurare a cikin birni, yana nuna yanayin yanayi. Kamar yadda aka nuna a cikin jumla ta baya, yankin da ke cikin gari yana nuna tsibirin zafi na birane (UHI) wanda zai iya kara yawan sultriness na daren bazara.

* **Lokacin hunturu** yana ganin yanayin sanyi gabaɗaya, kuma matsakaicin yanayin zafi na yau da kullun a watan Janairu shine  ° F (-12 ° C) yana da wuya, kuma na karshe 0 ° F (-18 ° C) -ko-karya karatu a Reagan National ya faru a ranar 19 ga Janairu, 1994.  Dangane da highs, Janairu kadai yana ganin  ° F (10 ° C) + highs a kan 8.6 days, yayin da 9 days a kowace kakar zama a ko ƙasa da daskarewa.&nbsp;

* **Lokacin bazara** yawanci ya bushe, yana da rana, kuma yana farawa a watan Maris. A Reagan National, daskarewa ta ƙarshe a matsakaici ta faru ne a ranar 27 ga Maris. Saboda saurin dumama, pollen ma yana da matsala a wannan lokacin na shekara. Muhimmin zafi da zafi suna farawa a ƙarshen Afrilu zuwa farkon Mayu, kodayake zafi mai bushewa yana yiwuwa a baya. Na farko  ° F (32 ° C) + high na shekara a matsakaici ya fadi a ranar 17 ga Mayu.
* **Lokacin bazara** yana da zafi kuma yana da danshi, tare da Yuli matsakaicin  ° F (26.6 ° C). Yanayin dare yana da dumi kuma sau da yawa yana da danshi, yana fadawa cikin ƙananan 70s ° F (21-23 ° C). Matsakaicin maki daga 62.4 zuwa 66.3  ° C) daga Yuni zuwa Agusta, yana nuna matsakaiciyar rashin jin daɗi. Akwai fiye da kwanaki 35 na  ° F (32 ° C) ko yanayin zafi mafi girma, duk da haka yanayin zafi na  ° F (38 ° C) ba ya faruwa a kowace shekara. A cikin 'yan shekarun nan, saboda wani bangare na karuwar UHI, mafi ƙarancin yau da kullun na  ° F (27 ° C) sun zama ruwan dare gama gari.&nbsp;

* .

* **Hasken rana** ya isa, jimlar awanni 2,529 a kowace shekara. Koyaya, hasken rana mai haske yana iya faruwa ƙasa da 50% na lokacin daga Nuwamba zuwa Fabrairu.
* Matsakaicin zafin jiki kamar haka:

The highest recorded temperature was  on July 20, 1930, and August 6, 1918, while the lowest recorded temperature was  on February 11, 1899, right before the Great Blizzard of 1899. The extreme low daily high temperature was , occurring one day before the all-time minimum, while the extreme high daily low temperature was  on July 23–24, 2011 and July 16, 1983. Monthly mean temperatures have ranged from  in January 1918 to  in July 2011, while the corresponding range for the annual mean is  in 1904 to  in 2012.

An ƙirƙiri Washington, D.C. don zama babban birnin ƙasar tun farkon sa.  Dokar zama ta 1790 ta buƙaci cewa yankin babban birnin zai kasance kusa da Kogin Potomac a cikin yankin da Maryland da Virginia za su mika wa gwamnatin tarayya.  Koyaya, ya ba wa shugaban ƙasar farko, George Washington, damar zaɓar ainihin wurin da yankin yake.  Daga nan sai Shugaba Washington ya zaɓi filin fili wanda ɓangarorinsa ke da nisan mil 10 (kilomita 16) kuma kusurwoyinsa kai tsaye arewa, gabas, kudu, da yamma na tsakiyarsa.  Yankin filin ya ƙunshi garuruwan Georgetown da Alexandria da ake da su, da kuma ƙananan ƙauyuka biyu, Hamburgh a cikin yankin Foggy Bottom da Carrollsburg kusa da haɗuwar kogin Potomac da Anacostia.

Dokar Mazaunin ta baiwa shugaban kasa ikon gano yankin babban birnin tarayya kawai har zuwa kudu da gabas kamar bakin Kogin Anacostia a Maryland. Koyaya, Shugaba Washington yana so ya faɗaɗa yankin zuwa kudu don iyakokinta su iya ƙunshe da garin Alexandria. A cikin shekara ta 1791, Majalisa ta yi gyare-gyare ga Dokar Mazaunin don amincewa da shafin da Shugaba Washington ya zaɓa, wanda ya haɗa da ɓangaren yankin da Virginia za ta ba da.

Yanayin babban birnin yana da fa'idodi da yawa na halitta: Potomac yana iya tafiya har zuwa yankin, yana ba da damar zirga-zirgar jiragen ruwa; tashar jiragen ruwa da aka kafa a Alexandria da Georgetown na iya samar da muhimmiyar tushe na tattalin arziki ga babban birni; kuma yankin yankin yana kusa da Yankin Arewa maso Yamma. A lokacin 1791-1792, Andrew Ellicott da mataimakansa da yawa, ciki har da Benjamin Banneker, sun bincika iyakar tsakanin yankin tarayya da jihohin Virginia da Maryland, suna sanya duwatsu masu alama a kowane ma'auni. Yawancin duwatsun har yanzu suna tsaye.

Wani sabon birni na tarayya, wanda aka sanya masa suna a shekara ta 1791 a matsayin Birnin Washington a cikin Yankin Columbia, an shimfiɗa shi a cikin wani yanki da ba a inganta shi ba a tsakiyar yankin tarayya mai murabba'in kilomita 100. Wannan birni, wanda Pierre (Peter) L'Enfant ya tsara, an iyakance shi zuwa arewa ta Boundary Street (yanzu Florida Avenue) a gindin tsaunuka na Atlantic Seaboard Fall Line, zuwa kudu maso gabas ta Kogin Anacostia, zuwa kudu yamma ta Kogin Potomac da yamma ta Rock Creek .  Kodayake L'Enfant ya tsara asalin garin a cikin shekara ta 1791, mai binciken ƙasa Andrew Ellicott ya sake duba shi a cikin shekara a cikin shekara na 1792 (duba Tituna da manyan hanyoyi na Washington, DC).  Sauran yankin an sanya su a matsayin Washington County (a gefen Maryland na Potomac) da Alexandria County (a gefe na Virginia).

### Iskandariya
An mayar da ƙasar daga Virginia zuwa jihar a 1846, wanda ya fara aiki a 1847. Wannan ƙasar a Virginia ta zama yankin zamani na Arlington County da tsohuwar ɓangaren Alexandria, Virginia, duka biyun su ne yankunan Washington, DC. Kabari na Arlington da Pentagon dukansu suna cikin Arlington, kodayake Pentagon tana da adireshin aika saƙo na Washington DC. Tsakanin 1790 da 1846, ana kiran Alexandria da Alexandria, DC.

### Georgetown
Georgetown da farko wani bangare ne na Maryland kuma shine kawai yawan jama'a a yankin da zai zama wani ɓangare na Washington, DC lokacin da aka fara kirkirar birnin tarayya amma wanda ya kasance birni mai zaman kansa sannan ake kira Georgetown, DC, har zuwa 1871 lokacin da aka haɗu da Washington City da Washington County, kammala tsarin Washington da Gundumar Columbia da ke zaune a kan iyakokin ƙasa iri ɗaya.

### Shirin McMillan
Babban abin tunawa na birnin ya haɗa da National Mall da manyan gine-ginen tarayya da yawa, abubuwan tunawa, da gidajen tarihi, gami da Lincoln Memorial, Washington Monument, da National Air and Space Museum. Tsarinsa ya dogara ne akan wanda rahoton Hukumar McMillan ya gabatar a cikin 1901.

Don kiyaye girman Babban Mall na Kasa, Fadar White House, Capitol, da sauran mahimman wurare daban-daban, duk birnin yana ƙarƙashin iyakokin tsayin gini.  An sanya wannan taƙaitaccen aiki kafin karni na 20 lokacin da jami'an gwamnati suka fahimci cewa tsarin "skyscrapers" na karfe zai iya mamaye birnin.  A cikin 1899, Majalisa ta kafa iyakacin tsayi ga Gundumar ta hana gine-gine masu zaman kansu daga tashi sama da ƙafa 130.  Sabanin sanannen imani, babu wata doka da ta taɓa ƙuntata gine-gine zuwa tsayin Capitol na Amurka ko Monument na Washington.t . 

Dokar tsawo da aka sake sabuntawa a cikin 1910 ta kawar da wannan matsakaicin matsakaicin. Sabon dokar, har yanzu tana aiki a yau, ta bayyana cewa babu sabon gini da zai iya zama fiye da ƙafa 20 fiye da faɗin titin da ke gabanta. Dokar yanzu an tsara ta a matsayin DC CODE ANN . § 6-601.05. Don haka, Washington tana da sararin samaniya mai sauƙi idan aka kwatanta da yawancin biranen Amurka. Koyaya, Gundumar tana kewaye da gine-gine masu tsawo a yawancin unguwanni da ke kusa kamar Arlington, Silver Spring, da Bethesda.

## Makwabta
Washington, DC ta kasu kashi takwas da kwamitocin ba da shawara 37 (ANCs) a cikin waɗannan unguwanni. Adadin unguwanni masu suna 127. ANCs suna aiki ne don ba da shawara ga majalisar birni ta Washington, DC kan batutuwan unguwa. Dokar ta buƙaci majalisa ta ba da ra'ayoyinsu nauyi sosai, kodayake abin da wannan ke nufi ya rage ga Majalisar don yanke shawara. Tun daga shekara ta 2000, yawan jama'a na unguwa da yawa sun canza sosai.

## Al'ummomin da ke kusa
Gundumar Columbia tana da iyaka da birane, garuruwa, ƙauyuka, da CDPs marasa kafa a Maryland da Virginia. Wadannan sune jerin wadannan al'ummomin da ke kusa.

## Bayanan Kula

## Manazarta