Te Hangarau Ā-Ao i roto i te Whakaiti i ngā Āhuatanga Horoi Whenua
Ko ngā horo whenua tētahi o ngā āhuatanga āwhata whenua e tino kitea ana i ngā rohe pārūrū pērā i a Initonīhia. Ko te āhua o ngā maunga, te nui o te ua, me ngā mahi a te tangata pērā i te whakawātea whenua, te hanga rori, me te keri maina ka kore e pumau te maha o ngā pari. Ka kino pea ngā pānga: te kino o ngā hanganga, te whakararuraru i te urunga atu ki ngā waka, ngā mate ōhanga, tae atu ki te mate. Nō reira, kāore e taea te whakawhirinaki ki te urupare ohorere anake i te wā o tētahi aituā te whakaiti i te horo whenua; me whai mahi ārai raraunga me te aroturuki tonu. Koinei te wāhi e whai wāhi nui ai ngā tikanga āwhata whenua—hei taputapu ki te "kite" i ngā āhuatanga o raro i te whenua me te kore e keri nui, ā, ka āwhina i te mārama ake ki ngā āhuatanga whakaoho me ngā rohe e pāngia ana e te horo whenua.
Te Tūranga o te Matawhenua ki te Mārama ki ngā Horo Whenua
I te nuinga o te wā, ka puta ngā horo whenua ina nui ake te kaha akiaki (hei tauira, te taumaha o te papatipu oneone/toka me te awe o te wai) i te kaha ātete (te kaha kutikuti rauemi me te piripono). Ko tētahi o ngā kī ki te whakaiti i te taumahatanga ko te tautuhi i ngā mata paheke, ngā paparanga ngoikore, ngā pakaru, me ngā tauira rere wai o raro i te mata ka taea te whakanui ake i te pēhanga o ngā pore. Heoi, he maha o ēnei wāhanga kāore e kitea mai i te mata. Ka tukuna e ngā tikanga ā-whenua he tikanga kore-whakangaro mō te mahere i ngā tawhā ā-tinana o te toka/oneone pēnei i te ātete hiko, te tere o te ngaru ru, te urupare hikohiko, me ngā rerekētanga o te kaha ā-papa. Kātahi ka whakamaoritia ēnei tawhā ki ngā mōhiohio ā-whenua-hangarau: te taumata mākū wai, te momo rauemi, ngā rohe huarere, ngā kōhao, me te hohonu o te toka papa.
I roto i te horopaki o te whakaiti i te kaha o te whenua, e toru ngā wāhanga matua e whakamahia ana te matawhenua: (1) te rangahau tuatahi i te ngoikore o te pari, (2) te whakamahere me te hoahoa i te whakapakari o te pari, me te (3) te whakatūpato wawe mā roto i ngā rangahau auau, ngā pūnaha pūoko rānei.
Tikanga Ātete-whenua (Ātete-ātete) mō te Mahere i ngā Papa Wai me ngā Papa Paheke
Ko te tikanga ātete whenua hiko tētahi o ngā tikanga rongonui mō ngā rangahau whenua whenua nā te mea he iti te utu, he ngāwari te kawe i ngā taputapu, ā, he aro ki te nui o te wai. He māmā noa te kaupapa: ka werohia he iahiko ki roto i te whenua mā roto i ngā irahiko, ā, ka inehia te rerekētanga pūmanawa kia puta ai te ātete kitea. Ko ngā rauemi kua mākū ki te wai he iti ake te ātete i ngā rauemi maroke, ko ngā toka mārō ia he ātete ake.
I ngā pari e pāngia ana e te whenua horo, ka taea e ngā hua o te whakatauira ātete 2D, 3D rānei te whakaatu:
– Ngā rohe kua mākū te wai, ngā ara turuturu rānei (ngā ara rere o te wai pāpaku/wai whenua) e ngoikore ai te pari.
– He paparanga uku, he oneone kua pākarukaru rānei, ā, he pahekeheke te mata i te wā e mākū ana.
– Ko te hōhonutanga o te toka papa me te matotoru o te oneone kua pāngia e te huarere, e whakatau ana i te pūmanawa o te kore pumau.
I roto i te mahi, ka whakahaerehia ngā rangahau me ngā whirihoranga hiko motuhake pērā i a Wenner, Schlumberger, Dipole-Dipole rānei. He maha ngā wā ka whiriwhiria te Dipole-Dipole nā te mea he pai te taumira mō te kite i ngā hanganga taha pērā i ngā whati me ngā papa paheke, ahakoa he tairongo ake ki te haruru. Me hono ngā whakamaoritanga ātete ki te whenua mata, te keri, ngā raraunga whakamātautau taiwhanga rānei hei karo i ngā hapa—hei tauira, ko te ātete iti ka tohu pea i te uku mākū, engari tera pea nā ētahi rauemi kawe hiko.
Te Whakaata Ru me te MASW mō te Whakaahuatanga Kaha Rauemi
Ko ngā tikanga rū whenua e whakamahi ana i te horapa o ngā ngaru pīataata i roto i te whenua. E rua ngā huarahi e whakamahia whānuitia ana hei whakaiti i te horo whenua ko te whakaata rū whenua me te MASW (Multichannel Analysis of Surface Waves).
1. Ka aromatawaihia e te rū whenua te tere o te ngaru-P (Vp) hei mahere i ngā paparanga me ngā rohe o ngā rauemi mārō. Ko ngā tere teitei ake e tohu ana i ngā toka kiato me te kaha ake, ko ngā tere iti ake e tohu ana i te oneone wetekina, i te toka kua pakaru rānei. He whai hua ēnei mōhiohio hei whakatau i te hohonutanga o te toka papa me ngā rohe matotoru kua pakaru e ngawari ana ki te horo whenua.
2. Ka arotahi a MASW ki ngā ngaru mata hei whiwhi i te tere o te ngaru kutikuti (Vs). Ka hono a Vs ki te pakari (te modulus kutikuti) ā, ka taea te whakamahi hei tautuhi i ngā paparanga ngohengohe ka pakaru pea. He whānui te whakamahinga o te MASW nā te mea he whai hua i ngā wāhi he nui te mahi a te tangata, ā, ka taea te mahi me te kore he pūtake pūngao nui.
Ko te painga o te tikanga rū whenua ko tōna kaha ki te hono tika i ngā tawhā ā-tinana ki ngā āhuatanga ā-pūkaha. He mea nui anō hoki ngā kōtaha Vs mō ngā tātaritanga pumau pari e whai whakaaro ana ki te urupare hihiri, hei tauira i ngā wāhi e pāngia ana e te rū whenua—ka taea e ngā rū whenua te whakaoho i ngā horo whenua nui.
Te Radar Whakauru Whenua (GPR) mō ngā Pakaru Papaku
Ka whakamahia e GPR ngā ngaru hikohiko auau-teitei hei mahere i ngā hanganga papaku o raro i te mata. He tino whai hua tēnei tikanga mō te kimi:
– Ngā pakaru me ngā rohe pakaru i runga i ngā pari,
– Ngā huringa i roto i te paparanga tata-mata,
– He kōhao iti, he ara wai pāpaku rānei.
Heoi, he iti noa iho ngā herenga o te GPR: ka tino heke te mahi a te GPR i roto i te paru, i ngā oneone tino mākū rānei nā te kaha o te ngaru. Nō reira, he pai ake te GPR mō ngā rauemi toka onepu, kirikiri, iti iho rānei te kawe hiko, me ngā rangahau pāpaku (hei tauira, he torutoru mita ki te tekau mita, i runga i ngā āhuatanga).
Ngā Tikanga Hikohiko me te Whakaoho mō te Mahere Tere
Ka taea e ngā tikanga hiko aukume (EM) pēnei i te EM31/EM34, me ētahi atu tikanga whakapūtanga hiko aukume rānei te mahere tere i te kawe hiko o te oneone, puta noa i te whānuitanga. I roto i ngā rangahau whenua horo, he whai hua ēnei tikanga mō:
– Te rangahau tuatahi hei tirotiro i ngā wāhi tino mākū, ngā wāhi tino kawe hiko rānei,
– Te tautuhi tata i te ara wai o raro i te mata,
– Āwhina ki te whiriwhiri i ngā wāhi ara hiko whenua, i ngā wāhi keri rānei.
Ko te painga matua o te EM ko tōna tere; ka taea e te kaiwhakahaere te hikoi i te ara me te kohi raraunga tonu. Ko te ngoikoretanga ko te whakamaoritanga he "whānui" ake i te ERT (Electrical Resistivity Tomography) ā, ka ngawari ki te pokanoa ki te konganuku huri noa i ngā wāhi noho.
Te Tātaritanga o te Microtremor me te Wiri mō te Tohu o te Rohe Ngoikore
Ka whakamahia e ngā tikanga microtremor (hei tauira, HVSR—Te Tauwehenga Tirohanga Whakapae ki te Poutū) ngā wiri taiao hei mahere i ngā āhuatanga hihiri o te whenua. Ahakoa e mōhiotia whānuitia ana mō ngā rangahau rū whenua, ka taea hoki e ngā microtremor te āwhina i te whakaiti i te horo whenua mā te tautuhi i:
– Te matotoru o te paru ngohengohe i runga ake i te toka papa,
– Te rerekētanga o te ātete e pā ana ki ngā āpure ngoikore,
– Ngā rohe e whakanui ana i ngā wiri kia ngoikore ake ai i te wā o ngā rū whenua, i ngā wiri waka rānei.
He whai hua te whakamahinga o te microtremor ina honoa ki ētahi atu tikanga pēnei i te MASW, te geoelectric rānei hei whakapakari i te whakamāramatanga.
Te Aroturukitanga Ā-whenua me te Ariā Whakatūpato Moata
Kāore te whakaiti i te taumahatanga e mutu i te mahere whenua. He maha ngā horo whenua e puta mai ana i ngā huringa o te wā, inā koa te pikinga o te mākū o te wai i te wā ua roa. Nō reira, he taputapu aroturuki kaha pea ngā rangahau ā-whenua auau (wā-roa). Hei tauira:
– ERT wā-wā hei tirotiro i ngā panoni ātete nā te urunga mai o te ua, te pikinga o ngā taumata wai whenua, te hanganga rānei o ngā ara turuturu hou.
– Te aroturukitanga rū whenua kore mahi hei kite i ngā huringa moroiti, i ngā nekehanga iti rānei e whakaputa ana i ngā tohu wiri.
– Te whakaurunga ki ngā pūoko hangarau whenua pēnei i ngā inenga whakatere, ngā inenga piezoelectric, me ngā ine ua hei hanga tauira whakatūpato moata e hangai ana ki ngā paepae.
I roto i tētahi pūnaha tino pai, ka whakaratohia e te matawhenua he pikitia ā-wāhi (kei hea ngā rohe ngoikore), ko ngā pūoko matawhenua ia ka whakaratohia he raraunga ā-wā (ina tata te kino o ngā āhuatanga). Mā te whakakotahitanga o ngā mea e rua ka pai ake te pono o ngā whakatūpato wawe.
Te Whakauru Raraunga me te Whakatau Whakaiti i te Whakaiti
He tino whai hua ngā raraunga ā-whenua ina whakauruhia ki ētahi atu huarahi: te mahere whenua, te tātari pari, te tātari whakamahinga whenua, me ngā raraunga ua me te rerenga wai. Ko te hua whakamutunga mō te whakaiti i te pānga ko:
– Mahere mō te ngoikore o te horo whenua (rohe mōrearea),
– Ngā taunakitanga hangarau (te rerenga wai o te pari, ngā pakitara pupuri, te whao oneone, te whakato anō i ngā otaota, te neke rānei),
– Te aro turuki i ngā mahere me ngā huarahi whakawātea.
Ko tētahi o ngā wero nui ko te whakamaoritanga kāore i te whakatikatikaina; nō reira, ko te manatoko i te mara pērā i te keri iti, te whakamātautau SPT, ngā tirohanga i waho, te tauira oneone rānei he mea nui tonu hei "pono whenua."
Te Katinga
He nui te takoha a ngā tikanga ā-whenua ki te whakaiti i te horo whenua nā te mea ka taea e rātou te mahere tere i ngā āhuatanga o raro i te mata, me te haumaru hoki, me te whai hua. Ka āwhina ngā tikanga hiko whenua ki te tautuhi i ngā mata wai me ngā mata paheke, ka maherehia e te rūma ru (whakaata me te MASW) te pakari me ngā rohe o te toka papa, ka āwhina ngā tikanga GPR me te EM ki te kimi papaku me ngā rangahau tere, ā, ka whakatuwherahia e te aroturuki wā-wā ngā whai wāhitanga mō te whakatūpato wawe i runga i ngā huringa o ngā āhuatanga o raro i te mata. Mā te whakaurunga pai i waenga i te ā-whenua, te matawhenua, ngā hangarau matawhenua, me te whakamahere ā-wāhi, ka taea te whakaiti i te mōrearea o te horo whenua—ka tutuki ai he whanaketanga haumaru ake mō ngā hapori i ngā wāhi pari.
Ki te hiahia koe, ka taea e au te whakarerekē i tēnei tuhinga kia nui ake te mātauranga (me ngā tohutoro me te rārangi pukapuka), kia rongonui ake rānei mō te mātauranga tūmatanui, me te tāpiri atu hoki i ngā rangahau take mai i ngā rohe motuhake o Initonīhia.
