Kwezinye iindawo zeplanethi yethu, sinokubona uhlobo lobume bendawo obugqunywe ziidiphozithi zelitye eziqhutywa ngumoya. Oku kubizwa indawo yokugcina amanzi. Ukuze olu hlobo lobume bendawo lubumbe, mhlawumbi, ixesha lamawaka eminyaka kuye kwafuneka ukuba kudlule, apho uqhwithela oluqhubekayo lothuli lubeke lo mbandela.
Kule nqaku, siza kutyhila kuwe ukubaluleka kwetanki yeLoess kunye neempawu zayo eziphambili.
Idama laseLoess kunye nokusekwa kwalo
Njengoko besesitshilo ngaphambili, kuthabatha ixesha lamawaka eminyaka ukuba umoya wenze ezi dipozithi kancinci kancinci. Kwezinye iindawo zehlabathi silufumana olu hlobo loqeqesho kwaye luyamangalisa. Xa indawo yokugcina amanzi i-Loess icanda imilambo yamanzi okanye isikwa ukwenza iindlela, ihlala igcina indawo emi nkqo. Kulapho ungenawo umaleko obonakalayo ngokwendalo.
Ukuhanjiswa kwediphozithi yeLoess kubonisa ukuba kukho imithombo yolwazi eyintloko yolwakhiwo: eyokuqala yidipositi yentlango eqokelelwa ngamandla omoya, kwaye eyesibini ngamathafa ezikhukula omkhenkce. Le mithombo mibini yoqeqesho inoxanduva lweLoess.
Eyona ndawo inkulu kwaye ibanzi kwiLoess deposits eMhlabeni zezo sinokuzibona kwintshona nakumantla e-China. Ezi dipozithi zenziwe kukuthuthwa komoya ukusuka kumazantsi enkqantosi e-Asia eseMbindi. Olunye lwezi fomati ziimitha ezingama-30 eziqokelelweyo kwaye yinto eqhelekileyo ukubona. Kubukhulu, umndilili usekwe kubungakanani beemitha ezili-100. Le ntlenga iyaqokelela kwaye, umzekelo, yiyo enika umbala kumlambo omthubi.
Ngakolunye uhlangothi, eUnited States, iidiphozithi zeLoess zibaluleke ngakumbi kwiindawo ezininzi apho uthutho lwentlenga lukhona kwimigama emide. Umzekelo, eMzantsi Dakota, Nebraska, Missouri nase Illinois, ziindawo apho singafumana khona ezi zakhiwo. Banokubonakala nakwezinye iziqithi zaseColumbia kumantla mpuma wePasifiki.
Umvelaphi
Kukho unxibelelwano phakathi kokuhanjiswa kweLoess kunye nemimandla emikhulu yezolimo eMidwest kunye neWashington. Ayisiyongxaki kwaphela le, kodwa inento yokwenza nayo. Kungenxa yokuba imihlaba ivela kolu lwandle ukuba ifakwa ngumoya zezinye zezona zichume kakhulu emhlabeni. Enkosi ngokuqokelela izinto, izakhi ziyanda. Iba yindawo etyebe kakhulu kwezolimo.
Ngokungafaniyo nokwenzekayo kwiidiphozithi zase China, ezithe zavela entlango, ezo zaseMelika naseYurophu ziyimveliso engangqalanga yomkhenkce. Ukuqanduselwa kunye nokunyibilika kangangesithuba seminyaka engamawaka amaninzi, kubangela ukwakheka kunye needipozithi zezidumbu ezonyusa ukuchuma komhlaba. Kwelinye icala, ezo dipozithi zenziwe ziintsika zentlabathi azichumi kwaphela. Banikezela kuphela ngezakhiwo ezinomhlaba omhle kodwa zinokuchuma okuncinci.
Imvelaphi yediphozithi yaseLoess eUnited States naseYurophu zibiyelwe ngobutyobo bomkhenkce. Xa amaqhekeza omkhenkce eqala ukubuyela umva ngenxa yokunyuka kwamaqondo obushushu, iintlambo ezininzi zemilambo ziye zavalwa ngeentsalela ezifakwe emanzini anyibilikayo omkhenkce. Kule meko, iarhente ehambisa intlenge ayingumoya, kodwa yimeltwater. Umoya nawo wenze isenzo sawo, ukusukela ukuba uvuthuza usiya kwicala lasentshona, utshayele kwaye wathwala uninzi lwentlabathi eyayikwithafa lomkhukula.
Izidumbu zazithuthwa zisuka kwezona zintle zisiya kwezona zinkulu. Ekuhambeni kwabo, baye bawa njengengubo kwimithambeka esempuma yeentlambo. Imvelaphi yezi zakhiwo inokungqinwa yinto yokuba iidiphozithi zeLoess zibhengezwe ngakumbi kwiindawo ezinamanzi apho kufumaneka khona eyona ndawo iphambili yokuhambisa amanzi ngomkhenkce. Umzekelo, iyaxatyiswa kakhulu kwiindawo zemilambo iMississippi naseIllinois kwaye ziye zibhitye njengoko umgama osuka entlanjeni uqhubeka usanda.
Obunye ubungqina bale mvelaphi ziinkozo ezi-angular ezinokuthi zibonwe zijiyile kwaye zenze iLoess. Kuyabonakala ukuba ziyafana nezo sinokuzifumana kumhlaba weliwa oveliswe ngokuguba komkhenkce.
Iimpawu zomzimba wetanki
Ezi dipozithi zenza i-10% yawo wonke umhlaba emhlabeni. Igama elithi Loess lithetha ukuba umhlaba ukhululekile kwaye ubunjwe ngama-50% esilika kunye nolunye udongwe oluyi-50%. Njengokuba umgama ukusuka kumthombo wonyuso ukwanda, izixa zokutya okuziinkozo ziyancipha kwaye, ngenxa yoko, iidipozithi ziyancipha kubungakanani kunye nobude.
Imithombo inokuba yeyasekhaya okanye ekude. Kungoko kukho iintlobo ezahlukeneyo zikaLoess. Umzekelo, ikalika okanye i-carbonate zezinye zezinto esizifumanayo eLoess. Uhlobo kunye nenani le-carbonate esinayo kuxhomekeke kwinkqubo yokwenziwa ngaphambi nasemva kokufakwa komhlaba kunye nemvula ehambelana nazo.
Ukukhululeka, imigangatho ayomelele kakhulu. Zomelele xa zomile, kodwa zisenokudilika ngokulula xa zifakwe emanzini. Umhlaba unokuqulatha phakathi kwe-10 kunye ne-15% lamanzi nge-porosity eyahluka phakathi kwama-34 nama-60%.. Ezi zinto zixabisekileyo ziyatshintsha kuxhomekeke kubungakanani bedongwe okanye isanti esinayo.
Njengoko besesitshilo ngaphambili, zifunwa kakhulu iidipozithi zezolimo olunzulu. Oku kwenza ukuba imisebenzi yokulima ibelula kwaye iqinisekise ukuba umoya wanele ngokwaneleyo ukuze umhlaba ube neepropathi kunye neengcambu zezityalo zikhule zikwimeko elungileyo.
Ndiyathemba ukuba ngolu lwazi unokufunda ngakumbi malunga nediphozithi yeLoess.