Ruwan ƙasa
 Ruwan ƙasa | |
|---|---|
| Bayanai | |
| Ƙaramin ɓangare na | Yanayin Aeolian |
Ruwan iska Dune yashi a cikin yanayin muhalli na yashi (psammosere) wanda ya haifar da cirewar turɓaya ta iska.
Ana samun saiti a bakin teku da gefen wuraren da ba su da ruwa, fashewa suna samuwa lokacin da iska ta lalata yashi a kan tsaunuka masu tsayi. Gabaɗaya, fashewar ba ta samuwa a kan dunes masu gudana sosai saboda dunes suna buƙatar ɗaure su har zuwa wani mataki, misali ta tushen shuke-shuke[1]. Wadannan raunin galibi suna farawa a kan sassan da suka fi girma na dunes masu tsayayya saboda yawan bushewa da rikice-rikice da ke faruwa a can, wanda ke ba da damar jan hankali da kuma raguwa lokacin da yashi ba shi da komai. Yawancin lokaci, wuraren da aka fallasa suna da sauri kafin su iya zama fashewa da faɗaɗa; duk da haka, lokacin da yanayi ya dace, rushewar iska na iya gurɓata farfajiyar da aka fallasi kuma ya haifar da tasirin rami wanda ke ƙara saurin iska na gida. Rashin lafiya na iya tasowa har sai ya buga wani abu mai narkewa, ko kuma yanayin da ya iyakance shi.[2] Abubuwan da suka lalace suna hawa gangaren da ke cikin bakin ciki kuma suna zama a gefen iska na fashewar wanda zai iya samar da dune wanda ke rufe ciyayi kuma ya haifar da mafi girma; tsari wanda ke taimakawa wajen ƙirƙirar dunes na parabolic.[3]
Lura cewa siffofin dutsen wuta waɗanda ke ɗaukar nau'in ɓacin rai wani lokacin ana kiransu ɓacin gwiwa, kamar "The Blowout" (kogi mai laushi) ko "Big Blowout Butte" a tsakiyar Idaho.[4]
Shuke-shuke
[gyara sashe | gyara masomin]Kodayake akwai tsire-tsire iri-iri da ke zaune a cikin mahalli na dune a duniya, yawancin nau'ikan shuke-shuke suna taka muhimmiyar rawa wajen tantance ko fashewar za ta samo asali ko a'a sakamakon yadda ƙarfin fatar kariya zasu iya hana lalacewa da kuma yadda wasu nau'ikan majagaba zasu iya hana ƙarin lalacewa idan dune ya fallasa.[5]
Fata mai kariya
A cikin yanayin farko, babban burin fata mai kariya shine tsayayya da rikice-rikice wanda zai samar da bayyanar budewa da haifar da fashewa. Don hana rushewa, ciyayi yana taimakawa wajen rage damuwa ta hanyar rufe farfajiyar da kuma ɗaure ƙasa tare. Fata mai kariya ya ƙunshi ciyayi wanda ke sama da ƙasa da kuma lalacewar shuke-shuke. Bugu da ƙari, fata mai kariya na iya haɗawa da nau'o'i iri-iri waɗanda zasu iya zama mahalli kamar ciyawa da gandun daji. Koyaya, idan yanayin ya canza, zai iya tasiri kai tsaye ga lafiyar ciyayi, wanda zai iya sa fata ya zama mai rauni; duk da haka, canjin canji na iya ɗaukar ɗan lokaci kuma yana iya zama daban don daidaitaccen dunes a cikin mahalli daban-daban.[6]
Nau'in majagaba
Da zarar rikice-rikice sun lalata wani ɓangare na fata mai kariya, bayyanar na iya fadadawa da lalata wasu ɓangarorin fata; duk da haka, wasu ciyayi, kamar nau'ikan majagaba, na iya zama a cikin buɗewa kuma hana duk wani fadadawa. Kodayake ana iya rarraba wasu nau'ikan shuke-shuke a matsayin masu mulkin mallaka, waɗannan shuke-tsire suna tsayayya da yawan adadin da aka ajiye da kuma yanayi rashin abinci mai gina jiki a cikin fashewa. Bugu da ƙari, idan fashewa ta samo asali, kayan da aka ajiye wanda ke tafiya daga cikin ɓacin rai na iya ci gaba da zama ajiya a mafi girma fiye da tsire-tsire na farko da zai iya girma, ko kuma ya sake daidaitawa. Mafi yawa saboda canje-canje a cikin yanayi, nau'in masu mulkin mallaka sun dogara sosai da yanayin muhalli, wanda zai iya canzawa sosai ba kamar ciyayi a cikin fata mai kariya ba.
Ana samun yashi na bakin teku kawai a cikin ƙasa daga rairayin bakin teku, kuma an kafa su yayin da iska ke hura yashi mai bushe a cikin ƙasa bayan rairayin kan teku. Ya biyo baya cewa wannan na iya faruwa ne kawai lokacin da akwai wani yanki mai laushi a cikin ƙasa daga rairayin bakin teku. A cikin lokaci, wannan wuri mara kyau za a mallake shi da nau'ikan majagaba. Wadannan nau'o'in (misali ciyawa na marram) za su daidaita dunes kuma su hana su motsawa. Tsarin maye gurbin shuka-shuke zai ga waɗannan dunes sun canza zuwa gandun daji (dangane da yanayi) kuma ƙasa mai girma za ta kasance.
Blowouts suna samar da muhimmiyar wurin zama ga tsire-tsire da Dabbobi.[7]
Rashin jituwa
[gyara sashe | gyara masomin]Rashin jituwa kalmomi ne na gaba ɗaya waɗanda ke bayyana dalilin da ke haifar da fallasawa a cikin fata mai tsire-tsire don ƙarshe ya zama tsari mai fashewa. Maimakon a bayyana su a matsayin abubuwan da suka faru, rikice-rikice kalmomi ne waɗanda ke bayyana yawan abin da karya ke haifar da buɗewa da faɗaɗa, duk da haka akwai nau'ikan rikice-rikicen da za su iya shiga cikin fata mai kariya. Duk da gaskiyar cewa dalilai da yawa na iya rinjayar tsarin fashewa, rikice-rikice yawanci suna da halaye uku waɗanda ke ƙayyade ko baƙin ciki zai samar kuma ya faɗaɗa. Abu na farko ya bayyana cewa rikice-rikice dole ne su sami girman shiga mafi girma fiye da ƙarfin fata mai kariya. A sauƙaƙe, idan fashewar ba za ta iya cire shuke-shuke masu kariya ba, to, lalacewar iska ba za ta taɓa haifar da ɓacin rai a cikin dunes ba. Abu na biyu ya tabbatar da cewa jigilar sediment a cikin fallasa zai kasance iyakance idan faɗin sararin samaniya ya yi ƙanƙanta. Da yake zaton cewa budewar ta yi yawa, tsawon ƙwaƙwalwar zai kasance mai ƙuntata sosai wanda ba ya ba da izinin fitar da ƙwayoyin ƙwayoyin ƙasa da yawa daga bayyanar. A ƙarshe, dukiya ta uku ta nuna cewa tsarin sararin samaniya na ɓangarorin da aka damu yana da tasiri sosai ga tsawon ɗaukar kaya da jigilar turɓaya a cikin fallasa. Idan akwai wurare masu yawa da ke da rikice-rikice waɗanda ke kewaye da juna a cikin hanyar iska, rushewar iska na iya cirewa da jigilar adadi mai yawa na barbashi, wanda zai iya haifar da fashewa. Don haka, kodayake sikelin rikice-rikice yana taimakawa wajen samar da fashewa, waɗannan halaye gabaɗaya suna taimakawa wajen nuna idan hanyoyin Aeolian na iya haifar da baƙin ciki ko a'a.
Tsarin iska da yanayin jiki
[gyara sashe | gyara masomin]Da zarar an nuna, yanayin fashewar ya dogara da hulɗar saurin iska da shugabanci tare da tsire-tsire da tsire na dune. Akwai nau'ikan fashewa da yawa waɗanda suka samo asali dangane da waɗannan dalilai; duk da haka, al'ummar kimiyya galibi suna amfani da nau'ikan sabuntawa guda biyu: trough da saucer. Kodayake babu wani dalili da ya sa aka kafa nau'in daya maimakon wani a cikin wani yanki, fashewar saucer gabaɗaya suna da siffofi na semicircular da saucer yayin da fashewar trough suna da siffofin da suka fi tsayi tare da zurfin tafki da gangaren da suka fi tsawo. Duk da haka, nau'ikan fashewar suna da tsarin da zai iya shafar iskar iska a cikin kwandon.
UseA cikin kwari, yanayin tsarin zai iya hanzarta kwarara da samar da jiragen sama wanda ke haifar da matsakaicin rushewa tare da bene na kwandon raguwa kuma a gefe fadada gangaren fashewar. Bugu da ƙari, lokacin da iska ke gudana a saman bangon gefen fashewa, jigilar turɓaya tana da iyaka a tsakiyar tsakiya na rami mai laushi, wanda ke haifar da samar da Dune na parabolic. Kodayake wasu karatu kamar Hesp da Pringle (2001) sun lura cewa iskar da ke karkata ga yanayin fashewa ta shiga cikin bakin ciki saboda yankin matsin lamba a cikin kwandon deflation kuma an jagoranta shi daidai da yanayin fashewar. Koyaya, a cikin binciken Smyth, Jackson, da Cooper (2014), ƙananan shaidu sun goyi bayan cewa ana jagorantar iskar iska tare da axis na fashewa, amma maimakon haka kwararar ta kasance mai ɗorewa a cikin hanyar da yake gudana kafin ko ya nuna wasu halaye kamar rabuwa da ke gudana.[8]
Saucer blowouts yana nuna raguwar iskar iska tare da kwandon raguwa yayin da tsarin ke fadadawa a tsawon lokaci ta hanyar juyawa kwararar da ke lalata bangarorin da fadada iska. Saboda saurin raguwa, saucers suna samar da gajeren, fadi, gangaren radial. Lokacin da iskar ta shiga wani nau'in saucer, saurin iska yana raguwa bayan shigar da shi kuma yana hanzarta a gefen iska na tsari. Yankin rabuwa yana tasowa tare da gangaren lee yayin da iska ta shiga cikin fashewa kuma ta ragu da sauri, duk da haka yana sake hanzarta yayin da ya sake haɗuwa da kwandon kuma ya gudana har zuwa lobes na ajiya, inda yashi ya zama mai kwashewa.[9]
Ko da yake sun fi tasiri da tsarin fashewa ke da shi a kan yanayin su, nau'ikan biyu suna da basins na raguwa har sai sun kai matakin da ba za a iya lalatawa ba. Binciken da Hesp (1982) ya gudanar ya nuna cewa tsawon ajiya ba shi da alaƙa da zurfin lalacewa amma a maimakon haka faɗin fashewa. A wasu kalmomi, yayin da lobe na ajiya ke ƙaruwa, faɗin fashewa yana ƙaruwa da rabo na 1:2 zuwa 1:3 a cikin fashewar saucer da 1:4 a cikin faskewar trough.[10]
Dubi kuma
[gyara sashe | gyara masomin]- Aeolian processes - Hanyoyi saboda aikin iska
- Sand dune stabilization - Ayyukan kula da bakin teku
- Redfieldia, wanda aka fi sani da ciyawa mai zubar da jini - Nau'in ciyawa
- Médanos
- Sand dune ecology
- Sandhills (Nebraska) - Yankin ciyawa mai matsakaici, savannah, da kuma shrublands ecoregion na Nebraska, Amurka
- Yardang - Yanayin da aka tsara na Aeolian
Manazarta
[gyara sashe | gyara masomin]- ↑ https://oceanfdn.org/ha/guguwar-harvey-a-sama-ta-mamaye-kogin-da-ke-karkashin-ruwa/
- ↑ Livingstone, Ian, and Andrew Warren. Aeolian Geomorphology: An Introduction. Wesley Longman Limited, 1996. Print.
- ↑ Livingstone, Ian, and Andrew Warren. Aeolian Geomorphology: An Introduction. Wesley Longman Limited, 1996. Print.
- ↑ Kuntz, M.A., Skipp, Betty, Champion, D.E., Gans, P.B., Van Sistine, D.P., and Snyders, S.R., 2007. Geologic map of the Craters of the Moon 30' X 60' quadrangle, Idaho. U.S. Geological Survey, Scientific Investigations Map SIM-2969. Map Scale: 1:100,000.
- ↑ Barchyn, Thomas E, and Chris H Hugenholtz. "Reactivation of Supply-limited Dune Fields from Blowouts: A Conceptual Framework for State Characterization." Geomorphology, 201 (2013): 172-182.
- ↑ Barchyn, Thomas E, and Chris H Hugenholtz. "Reactivation of Supply-limited Dune Fields from Blowouts: A Conceptual Framework for State Characterization." Geomorphology, 201 (2013): 172-182.
- ↑ Barchyn, Thomas E, and Chris H Hugenholtz. "Reactivation of Supply-limited Dune Fields from Blowouts: A Conceptual Framework for State Characterization." Geomorphology, 201 (2013): 172-182.
- ↑ Hesp, Patrick. "Foredunes and Blowouts: Initiation, Geomorphology and Dynamics." Geomorphology, 48.1 (2002): 245-268.
- ↑ Hugenholtz, Chris H., and Stephen A. Wolfe. “Form-flow Interactions of an Aeolian Saucer Blowout.” Earth Surface Processes and Landforms, 34 (2009): 919-928.
- ↑ Hesp, Patrick. "Foredunes and Blowouts: Initiation, Geomorphology and Dynamics." Geomorphology, 48.1 (2002): 245-268.