Kwimekaniki yomhlaba kwahlulwa iintlobo ezintathu eziphambili zomhlaba: ezingabambeki, ezibambeneyo kunye nemihlaba yemvelaphi yezinto eziphilayo. Ukongeza, kukho namatye, kodwa wona awafundwa kwimekaniki yomhlaba, koko kwinkalo yesayensi ebizwa imekaniki yamatye.
Imihlaba engaqiniswanga
Imihlaba engabotshelelwanga okanye engeyonxibelelanayo yileyo imixholo yayo engabotshwanga nangasiphi isixhobo sokubopha. Kwimeko eyomileyo, xa ingaphantsi kwempembelelo yokufuma, amalungu aqinileyo omhlaba ongabotshelelwanga akhululekile ngokupheleleyo kubunzima bomhlaba, yaye phakathi kwawo kukho kuphela ukungqubana, okubizwa ngokuba kukungqubana kwangaphakathi. Kumhlaba ongabotshelelwanga kubalwa oku kulandelayo:
- Iibhloko, ubukhulu beenkozo 200 – 2000 mm
- Iqhoboshi, ub. beenkozo 60 – 200 mm
- Igrabile, ubukhulu beenkozo 2 – 60 mm
- Isanti, ubukhulu beenkozo 0,02 – 2 mm
- Uthuli, ubukhulu beentlenga 0,002 – 0,02 mm.
Kuyaphawulwa ukuba iqela lothuli ngamanye amaxesha libizwa ngokuba ludaka (engl. silt, nem. Schluff). Nangona kunjalo, njengoko apha kuthi udaka luthetha uhlobo oluthile lomhlaba wemvelaphi ye-organic, eli gama kweli qela linokubangela ukungaqondani.
Umz. 1 - Umhlaba oyisanti
Imihlaba edibeneyo
Imihlaba ebambeneyo okanye imilambo ye-coherent yimihlaba enamalungu aqinileyo abophelelene omnye komnye nge-cohesion. Imihlaba ye-coherent inokuba neempawu zomzimba ezingazinzanga kakhulu, ezitshintsha ngokulula phantsi kwempembelelo yamanzi. Kumihlaba ebambeneyo kubalwa leyo inamalungu aqinileyo anobukhulu obungaphantsi 0,002 mm. Umhlaba onamalungu ubukhulu becala 0,002 – 0,0002 mm ubizwa udongwe, yaye ukuba la malungu ubukhulu bawo 0,0002 – 0,00002 mm, ke ubizwa udongwe lwekholayidi.
Kwindalo udongwe olumsulwa lufumaneka kunqabile, koko luhlala luxutywe nezinye izithako, ezifana nesanti nothuli, nto leyo ebizwa ilovača; udongwe olunelitye lekalika lubizwa laporovita glina (lapor), kanti udongwe olunemagnesium ngu uma. Ngokuqhelekileyo kwamkelwa ukuba umhlaba oqulethe ngaphezu ko 50% wezithako ezibumdaka ubizwa masna glina okanye nje glina, kanti umhlaba one ngaphantsi ko 50% wezithako ezibumdaka ubizwa glinovito tlo. Umhlaba oqulethe ngaphantsi ko 5% wezithako ezibumdaka uthathwa njengonempawu zomhlaba ongadityaniswanga.
Eyona ndlela ikhawulezayo nekulula kakhulu yokuvavanya ukuba umhlaba othile ungowaliphi iqela kukomisa isampuli uze uzame ukuyityumza phakathi kweminwe. Imihlaba engadibaniyo iyawa ngoko nangoko. Imihlaba enodongwe iyatyumza phakathi kweminwe ibe ngamaqhekeza amancinci, yaye udongwe luba lukhuni phantse njengelitye.
Sl. 2 - Udongwe oludongwe
Imihlaba yemvelaphi yezinto eziphilayo
Le mithombo yomhlaba iquka inxalenye enkulu yezinto eziphilayo okanye zezityalo, kunye nezinto ezibunyiweyo nodongwe nezinye izinto. Ngenxa yomxholo wezinto eziphilayo, le mithombo yomhlaba ayizinzanga kakhulu yaye ifunxa amanzi kakhulu, ngenxa yoko ayizinzanga kwaye ayinakusebenza njengomhlaba oxhasayo, okanye njengento yokwakha izakhiwo zomhlaba. Kulo mhlaba kubalwa humus, mulj no treset.
I-Humus ngumhlaba ochumileyo, okwindawo engaphezulu yolusu lomhlaba, ubukhulu bawo buhlala buliqela leedesimitha. Uqulunqwe ngumxube wezinto eziphilayo nezamaminerali oneebhaktheriya ezininzi. Xa kusenziwa iindonga zomhlaba, iindlela zendlela nezinye iimisebenzi efanayo emhlabeni, kwakunye xa kugrunjwa kwindawo eboleka izinto zokwakha imisebenzi yomhlaba, kufuneka kumbiwe kususwe wonke umaleko we-humus, onokusetyenziswa kuphela ukukhusela amathambeka omhlaba ekukhukulisekeni ngamanzi.
Sl. 3 - I-Humus
I-sludge yenziwe ngumxube wezinto eziphilayo ezikwimo yamasuntswana amancinane kakhulu kunye nezinto zeminerali ezifana nodongwe, uthuli nesanti. Ifumaneka ezantsi kwemilambo namachibi angaphambili.
Ipeat yenziwe sisixa esikhulu sezinto zezityalo nezinto eziphilayo ngohlobo lweentsinga, inomlinganiselo omncinane wezinto zezimbiwa.
Imvelaphi yomhlaba
Ukuba besinokwenza isiqendu kumaleko womhlaba, besiya kufumanisa ukuba wona uqulunqwe ikakhulu ngumhlaba womphezulu – ihumus enomaleko omncinane, emva koko ngumhlaba ongaphantsi oqulunqwa ngomnye okanye nangaphezulu umaleko oneendawo ezahlukeneyo nezityebileyo ngobukhulu obahlukeneyo, yaye ekugqibeleni lilitye eliqinileyo. Umhlaba womphezulu uvelile ikakhulu ekuwohlokeni kwezinto zezityalo nezezinto eziphilayo, kanti umhlaba ongaphantsi uvelile ekuwohlokeni kwelitye eliqinileyo.
Ukuwohloka kwilitye eliqinileyo kwenzeka ngenxa yeempembelelo zemozulu okanye ngenxa yesenzo sentaba-mlilo. Iimpembelelo zemozulu zinokuba ngoomatshini okanye zibe zezekhemikhali. Ukuba inkqubo yokuwohloka kwilitye eliqinileyo kukudibana kweeminerali neoksijini, oko kukuthi ukuwohloka ngokuxutywa neoksijini, kwaye ukuba kukudibana namanzi, oko kukuthi ukuwohloka ngokuhlanganiswa namanzi. Isenzo sentaba-mlilo sesekhemikhali. Ngenxa yobushushu obuphezulu ilitye eliqinileyo liguquka libe luthuthu lwentaba-mlilo.
Inkqubo yokubola kwelitye eliqinileyo nokuguquka kwalo libe ngumhlaba inokwenzeka endaweni enye “in situ” okanye ngothutho. Ukuhanjiswa kweendawo ezibolileyo kwenziwa ngamanzi_, apho kuvela khona imihlaba ye-alluvial, ngumoya, xa iba yimihlaba ye-eolian okanye ngumkhenkce, xa kwakheka imihlaba ye-glacial. Ngexesha lothutho lweziqwenga ezibolileyo kunye nezahlulo zeli litye liqinileyo kuqhubeka ukuncipha kobukhulu ngenxa yokubethana, ukuxabana nokuhlanjwa, apho zivezwe khona ngexesha lothutho. Ngenxa yeso senzo, imiphetho yeziqwenga eziqhekeziweyo iyajikeleza, iincindi ezintsha ziyasikwa zibe zincinci, imiphetho yazo iphinda ijikeleze, njalo-njalo kude kube kuphele uthutho. Ubungakanani nemilo yeendawo eziqinileyo zixhomekeke ekuqineni kwelitye, ubude bothutho, uhlobo lothutho njl. Ngenxa yoko imilo yeengqekembe eziqinileyo emhlabeni yahlukeneyo kakhulu: ingqukuva, i-oval, eneemiphetho ebukhali okanye ejikelezileyo, engunxantathu njl. Iindawo eziqinileyo ezinobungakanani 0,02 – 0,002 mm, elo qela kwinkqubo yobunjineli bomhlaba libizwa uthuli, ubukhulu becala zingqukuva okanye zine-oval. Ezi ndawo ezinobungakanani obungaphantsi kwe0,002 mm, elo qela libizwa udongwe, zinemilo efana namaxolo. Iinqununu ezinkulu zesanti, igrabile kunye neengqalutye zinokuba neendlela ezahlukeneyo: ezibhokisi, ezijikelezileyo, ezicaba, njl. Iinqununu ezibhokisi zitshintsha imilo yazo nzima ngakumbi, ezicaba lula. Ngenxa yoko imihlaba equlunqwe ikakhulu ziincindi ezicaba ingatshintsha ngokulula ukwakheka kwayo.
Kuyacaciswa ukuba eminye imihlaba, ulwakhiwo lwayo sele lugqityiwe ngokupheleleyo, ngamanye amaxesha kamva igutyungelwa ziidiphozithi ezintsha, ukuze umhlaba owawusele wakheka ngaphambili uhlale nzulu, logama kwidiphozithi entsha kubunjwa omnye umhlaba ongenanto yakwenza nowangaphambili. Lo mhlaba owawusele wakheka ngaphambili nowagutyungelwa kamva yidiphozithi entsha ubizwa ngokuba lilizwe elingcwatyiweyo. Ezi zidla ngokuba yimihlaba yeenkcubeko, eyayilinywa yaza kamva yagutyungelwa ziidiphozithi zothuli lwe-loess ezivuthelwe ngumoya, kodwa ezi diphozithi zinokuba zezemilambo. Umhlaba ongcwatyiweyo ubonakala ngombala omnyama kwaye kunokuba nemaleko emininzi enjalo ukuba le nkqubo iphindaphindiwe amaxesha amaninzi.
Imihlaba yealluvial
Imihlaba ye-alluvial yenziwa kukufakwa kweengceba eziqinileyo ngexesha lokuthuthwa ngamanzi. Ukufakwa kuxhomekeke kwizinto ezininzi, ezona zibalulekileyo kuzo sisantya sokuhamba kwamanzi, ubungakanani bezinto ezithuthwayo kunye nobuninzi bezinye izinto ezifana neetyuwa, ikalika njl. Kwisantya esikhulu sokuhamba kwamanzi kufakwa kuphela izinto ezinkulu, ngoxa ezincinci zingafakwa, koko ziqhubeka zithuthwa. Ngenxa yoko izinto eziqinileyo ezinkulu zifakwa kwinxalenye ephezulu yomlambo, kufutshane nomthombo, apho isantya sokuhamba kwamanzi sikhulu. Njengoko isantya sokuhamba kwamanzi sihla, kufakwa izinto ezincinci ngakumbi. Emanzini azolileyo, ngaphandle kokuhamba, ngokomgaqo kufakwa ezona zinto ziqinileyo zincinci. Naphi na apho ukuhamba kwamanzi kuncipha khona, kuvela ukwakheka okukhulu kokufakwa, njengoko kusenzeka kwindawo ekhukhulweyo xa amanzi ephuma emlanjeni, emva koko emlonyeni wemilambo, phambi kweedama njl.
Ukutyhubela kwamasuntswana amancinane kakhulu odongwe lwekholoyidi kunokuhlala ixesha elingenammiselo ngenxa yesenzo se-electrochemical, esenzeka phakathi kwamasuntswana amancinci anobukhulu obungaphantsi kwe 0,0002 mm xa ethi nkxu emanzini. Kule meko amasuntswana aqinileyo athwala kuwo umthwalo wombane ofanayo (ongalunganga), nto leyo ebangela ukuba agxothane omnye komnye aze ahambe kulwelo ngesantya esikhulu ngakumbi kokukhona emancinci. Ezi ziintshukumo zikaBrown. Ngenxa yezi ntshukumo, ukutyhubela kwamasuntswana aqinileyo emanzini kuyacotha kakhulu yaye kunokuhlala ixesha elingenammiselo.
Sl. 4 - Umhlaba wealuvial
Umhlaba we-eolian
Imihlaba ye-aeolian yenziwa kukuthuthwa ngumphunga womoya wamasuntswana aqinileyo. Ziyahluka iindidi ezimbini zomhlaba we-aeolian les kunye dine. Les iqulunqwa ngamasuntswana aqinileyo anobukhulu obumalunga ne-0,05 mm okanye amancinci kancinane, ancanyathiselwe omnye komnye yi-calcium carbonate. Ngenxa yoko, xa ikwimeko eyomileyo, i-les inamandla amakhulu. Iindawo ezigrunjwayo kwi-les zinokuma ngeendonga ezithe nkqo eziphakamileyo kakhulu. Nangona kunjalo, ukuba i-les imanziswa kakhulu, ilahlekelwa ngamandla ayo ibe isuka lula. Kuyaziwa iimeko zeedipozithi ze-les ze-Bežanijska kosa kufuphi neBelgrade, ezime ngeendonga ezithe nkqo kwiimitha ezingaphezu kwe-20m. Nangona kunjalo, kwiindawo apho kwakhiwe khona iindawo zokuhlala kufutshane nemiphetho, njengakwimeko yesitalato iČunarska eZemun, apho kukho ukumanzi rhoqo ecaleni nje kwethambeka leplato ye-les ngenxa yokuchithwa kwamanzi asetyenzisiweyo, amathambeka e-les ayawa kwaye uzinzo lomhlaba we-les kufuphi nomphetho luyasongelwa.
Iidyun ziinduli ezishukumayo zesanti engabotshelelwanga efunjwe ngumoya. Ezi nduli, phantsi kwesenzo somoya, zisasazeka ngokukhawuleza zize ziphinde zenziwe kwakhona, nto leyo ezenza zibe yingozi yokugqunywa nokudilika kweendawo zokuhlala nezithuthi.
Umz. 5 - Umhlaba we-aeolian
Imihlaba ye-glacial
Umhlaba womkhenkce uveliswa ngokuthuthwa ngumphunga womkhenkce kwamasuntswana aqinileyo omhlaba. Umhlaba womkhenkce unomgangatho owahlukileyo kunowomlambo, kuba wenziwe ngamasuntswana aqinileyo anobukhulu obufana ngokulinganayo, oko kukuthi amatye ajikelezileyo, igrabile (imoreyne) okanye isanti, ezishiyekileyo emva kokunyibilika komkhenkce. Kwiimaleko zamachibi omkhenkce angaphambili kukho udongwe lomkhenkce.
Umz. 6 - Umhlaba we-glacial