Kogin Bear (Ruwa na Kogin Feather)

**Kogin Bear** wani yanki ne na Kogin Feather a cikin Nevada_(U.S.)" id="mwGA" rel="mw:WikiLink" title="Sierra Nevada (U.S.)">Sierra Nevada, yana kewaye da yankuna huɗu na California: Yuba, Sutter, Placer, da Nevada . Kimanin kilomita 73 (kilomita 117) tsawo, kogin yana gudana gabaɗaya daga kudu maso yamma ta hanyar Sierra sannan yamma ta hanyar Kwarin Tsakiya, yana zubar da ruwa mai zurfi na murabba'in kilomita  (kilomitara 760).

Ofishin Kula da Lafiya na Muhalli na California ya bada shawara mai aminci ga duk wani kifi da aka kama a cikin Kogin Bear saboda matakan mercury masu yawa.

## Yanayin ƙasa

Kogin Bear ya samo asali ne a Emigrant Gap, a matsayin karamin rafi a kan iyakar Nevada da Placer Counties a cikin Tahoe National Forest. Ruwan ruwa suna kan tudu nan da nan zuwa kudancin Kogin Yuba na Kudu da arewacin Kogin North Fork American. Kogin yana gudana zuwa yamma zuwa cikin kwarin Bear sannan ya shiga wani zurfi da kuma kunkuntar gorge, yana wucewa cikin al'ummar Dutch Flat. Ci gaba tare da layin Nevada-Placer County yana karɓar Steephollow Creek daga arewa kafin ya faɗaɗa zuwa cikin Rollins Reservoir, wanda aka kafa ta   high Rollins Dam gabashin Chicago Park. Yayinda yake wani ɓangare na tafkin, kogin ya haɗu da Greenhorn Creek daga arewa.

A ƙasa da madatsar ruwan kogin yana gudana daga kudu maso yamma ta hanyar tuddai na Sierra, bayan Colfax da Meadow Vista, ta hanyar Lake Combie da kuma gajeren amma mai tsawo a saman Garden Bar. Ba da daɗewa ba ya faɗaɗa zuwa Camp Far West Reservoir, inda ya fara bayyana iyakar Placer-Yuba County. Ƙarin yamma yana gudana cikin Kwarin Sacramento inda ya zama babban ambaliyar ruwa. Farawa a Wheatland ya zama iyakar Yuba da Sutter Counties. A 'yan mil a ƙasa da wannan batu yana karɓar Dry Creek daga arewa, sannan yana gudana cikin Kogin Feather a Nicolaus, mil 11 (18  sama da haɗuwar Feather tare da Kogin Sacramento mafi girma, kuma kimanin mil 20 (32  saboda kudancin Yuba City-Marysville.

Tare da  kwararar shekara-shekara na 410 cubic feet a kowace dakika (12 m a Wheatland, Bear shine mafi ƙanƙanta babban mai ba da gudummawa na Kogin Feather. Ruwan wata-wata yana daga 1,1 cubic feet a kowace dakika ( " data-ve-ignore="true">m a watan Maris zuwa 20 cubic feet da kowace dakika (0.57 m3/s).  Saboda ruwan Kogin Bear yana da ƙananan tsawo idan aka kwatanta da sauran kogunan Sierra, ruwan sama, ba dusar ƙanƙara ba, shine babban tushen runoff. Har ila yau, yawan kwararar yana da tasiri sosai ta hanyar madatsun ruwa da yawa a kan kogi.

## Ilimin ƙasa
Kogin Bear an dauke shi rafi mara kyau, kamar yadda ya fi girma, kogin da ke cike da dusar ƙanƙara ya gudana ta hanyar tashinsa a zamanin d ̄ a. Miliyoyin shekaru da suka gabata saman Kogin Yuba na Kudu (sama da Tafkin Spaulding) ya gudana cikin Kogin Bear a Emigrant Gap . Fashin teku na rafi, mai yiwuwa ya taimaka da glaciation a lokacin Ice Ages, ya sa aka "kama" saman Bear a cikin ruwan Yuba zuwa arewa kuma ya rage Bear da kimanin kilomita 25 (40  a sakamakon haka.

## Tarihi

Yankin Kogin Bear ya daɗe yana gida ga mutanen Nisenan.

Gidansa yana cikin Ƙasar Zinariya ta California kuma yana ɗaya daga cikin yankuna masu arziki na karni na 19 na California Gold Rush . Manyan wuraren hakar ma'adinai a cikin kogin Bear sun hada da You Bet, Red Dog, Dutch Flat, Gold Run, Waloupa, Little York, da Chalk Bluff . 

Yawancin ƙasa a cikin kogin Bear sun canza sosai ta hanyar hakar ruwa. A You Bet da Red Dog an wanke "47,000,000 cubic yards (36,000,000 m3) na dutse mai ɗauke da zinariya; a Dutch Flat 105,000,000 cubic yadudduka (80,000,000 m3); kuma a Gold Run 128,000,000 cubic yard (98,000,000 m3). 

## Injiniya
An yi amfani da Kogin Bear sosai kuma an karkatar da shi don ban ruwa, samar da ruwa na gida, da samar da wutar lantarki. Kogin ya karu sosai ta hanyar karkatarwa daga babban tafkin Kogin Yuba zuwa arewa, ta hanyar Drum-Spaulding Hydroelectric Project da Yuba-Bear Hydroele Electric Project. Tsohon, wanda aka kammala a cikin 1910s da farko don samar da wutar lantarki mallakar PG&amp;amp;E ne; Gundumar Ruwa ta Nevada (NID) ce ta gina ƙarshen a cikin 1960s. Kodayake ana amfani da ayyukan daban-daban guda biyu, tsarin rikitarwa na wasu tafkuna 40 a Tsakiyar Tsakiya da Kudancin Yuba da kuma kan Kogin Bear yana da alaƙa sosai, kuma yana aiki a matsayin ɗaya.

    na ruwa daga Kogin Yuba yana shiga cikin Kogin Bear ta hanyar Drum Canal, wanda ramin tafkin Spaulding ke ciyar da shi.  Mafi girman madatsun ruwa a Kogin Bear suna a Dutch Flat Forebay da Dutch Flat Afterbay, duka ƙananan madatsun ruwa na karkatar da wutar lantarki. Ruwa daga kogin Bear na sama da Drum Canal suna wucewa ta waɗannan madatsun ruwa kuma suna fitar da wutar lantarki a Drum, Dutch Flat da Chicago Park.

A ƙasan Gidan Wutar Wutar Lantarki na Chicago Park, a mahaɗin Greenhorn Creek, Rollins Dam ne ya kama kogin Bear, wanda ya samar da    tafki. Tafkin yana tanadin ruwa don ban ruwa da wutar lantarki, kuma yana yin amfani da muhimmiyar manufar tarko da ruwa daga aikin hakar ma'adinan ruwa na farko a cikin babban kogin Bear. Kai tsaye a ƙasan Rollins Dam ya ta'allaka ne da Dam ɗin Diversion River, wanda ke karkatar da kusan    na ruwa a kowace shekara a cikin Kogin Bear River Canal, wanda ke ba da dama ga al'ummomin karkara a cikin Placer County tsakanin Colfax da Auburn .  Ruwan da ya wuce kima daga magudanar ruwa yana shiga rafin kogin Amurka ta wani gidan wuta a tafkin Folsom .  

### Dam proposals
A watan Yulin shekara ta 2011, an bayyana aikin madatsar ruwa na Kogin Bear a karkashin binciken wani rukuni na gundumomin ruwa na waje. Gundumar Ruwa ta Kudu Sutter (Trowbridge), tare da biranen Napa, American Canyon, da Palmdale, Hukumar Ruwa ta Castaic Lake, da Gundumar ruwa ta San Bernardino Valley, sun ba da binciken farko game da sanya sabon madatsar ruwa a arewacin yanzu Camp Far West Reservoir da kudancin Combie da Rollins reservations da ke sama. Dam din zai kasance a cikin gundumar ruwa ta NID (Nevada Irrigation District) kuma zai ambaliya sassan Nevada County da Placer County. Za a gabatar da madatsar ruwan Garden Bar a wuraren da aka riga aka ware a matsayin wuraren kiyayewa da wuraren namun daji, kuma tafkin da ya haifar zai mamaye mazaunin namun daji da itacen oak da savannah.

Saboda da cewa ruwan da zai cika babban tafkin da aka tsara (,000 zuwa 400,000 acre-feet (,000,000 zuwa 493,000,000 m3), bisa ga binciken, mafi girman zaɓi zai zama murabba'in kilomita 3 (7.8 )) an riga an rarraba shi don tabkuna na yanzu ta madatsun ruwa a kan Kogin Bear a Camp Far West, Combie, da Rollins, ainihin yiwuwar aikin yana da hasashe, kuma ya haifar da shakku game da ainihin manufar tayin.

Wani bayani daga binciken ya ce"Rashin Ruwa: Rahoton ya amince da kasancewar "batutuwa da yawa da za a buƙaci warwarewa don tabbatar da kasancewar wannan ruwa da ikon isar da wani ɓangare na shi ta hanyar Delta, idan ana so. "

Saboda rashin hujja na tattalin arziki da adawa daga ƙungiyar kiyayewa, Sierra Watch, amintattun ƙasa na gida, ranchers, da kwamitin masu kula da duka Placer da Nevada Counties, gundumar ruwa ta bar madatsar ruwan da aka tsara a watan Yulin 2012.

A cikin 2014, NID ta sake fitar da wani shiri don sabon dam/tafki akan Kogin Bear a wurin Parker, wanda ke saman tafkin Combie. Bayan amincewa, dam ɗin Centennial da aka tsara zai adana kusan     An ƙirƙiri kamfen na "Save the Bear, Stop Centennial" don adawa da shawarar da ƙungiyoyin kare muhalli masu zaman kansu, da Foothills Water Network da South River Citizens League (SYRCL),  tare da goyon bayan sauran al'umma da kungiyoyin kiyayewa. kamar Sierra Watch.  

## Dubi kuma

* Jerin koguna na California

## manazarta