Sarautar Bruun

Dokar Bruun taro ne don kimanta girman koma baya na bakin teku na bakin teku don mayar da martani ga canje-canje a matakin teku. An buga shi ne a shekarar 1962 ta hanyar Per Moller Bruun,  mulkin Bruun shine na farko da ya ba da dangantaka tsakanin hauhawar matakin teku da koma bayan bakin teku.  Dokar tana da sauƙi, jujjuyawar ma'auni guda biyu, kuma tana ci gaba da amfani da ita don kimanta koma bayan bakin teku don mayar da martani ga hauhawar matakin teku, duk da zargi da gyare-gyare, da kuma wadatar samfuran da suka fi rikitarwa.

## Lissafin
Dokar Bruun kasa ba da alaƙa ta layi tsakanin hauhawar matakin teku da koma bayan bakin teku bisa ga ka'idar bayanin martaba, wanda ke tabbatar da cewa bayanin martaba na bakin teku yana riƙe da siffar daidaitawa, kuma yayin da matakin teku ke tashi sararin samaniya yana tilasta wannan bayanin martaba zuwa ƙasa da sama don adana siffarsa dangane da sabon matakin teku.[1] Saboda haka, nazarin mulkin Bruun ya ɗauka cewa rairayin bakin teku na sama ya lalace yayin da bayanin bakin teku ke motsawa zuwa ƙasa, kuma an ajiye ƙarar kayan da aka rushewa a bakin teku, wanda ke haifar da hauhawar ƙasan kusa wanda ke kula da zurfin ruwa.[2] Dokar Bruun ta yi hasashen koma bayan tattalin arzikin bakin teku ya zama kusan sau 10 zuwa 50 na hauhawar matakin teku, dangane da gangaren rairayin bakin teku..

Bayanan lissafi na mulkin Bruun shine:

R = \frac{SL}{h+B} = \frac{S}{\tan\beta}

## Tarihi
A shekara ta 1954, Per Moller Bruun ya buga takarda  wanda ke kwatanta bayanan rairayin bakin teku da daidaito na bakin teku.  Ci gaba a kan waɗannan ra'ayoyin, a filin 1962 ya buga takarda "Sea-Level Rise as a Cause of Shore Erosion",  wanda ya fara ba da dangantaka tsakanin hauhawar matakin teku da koma bayan bakin teku na daidaitattun bayanan rairayin bakin teku. **' Ba a ba da sunansa ba har sai 1967, lokacin da Schwartz ya buga "The Bruun Theory of Sea-Level Rise as a Cause of Shore Erosion" wanda ya ba da cikakken bayani game da dakin gwaje-gwaje da gwaje-gaje na ka'idar kuma ya kammala cewa "tsarin daga nan gaba za a san shi da 'Bruun's Rule'.

Per Bruun tun daga lokacin ya buga ayyukan don bayyana iyakoki da amfani da samfurinsa, gami da "Binciken Yanayi don Amfani da Dokar Bruun ta Rushewa" a cikin 1983,  da kuma "The Bruun Rule of Erosion by Sea-Level Rise: Tattaunawa akan Amfani da Dimensional Biyu da Uku" a cikin 1988. Wadannan wallafe-wallafen suna tsara iyakokin doka da amfani da kuma jaddada cewa, kodayake wannan samfurin yana da ma'ana biyu, ana amfani da shi ga mahalli uku a aikace. Bruun ya bayyana cewa dokar "dole ne a yi gyare-gyare na gaskiya"  don amfani da amfani.

Kamar yadda Bruun ya yarda, mulkin Bruun doka ce mai sauƙi kuma saboda haka an canza shi sau da yawa, don lissafin ƙarin dalilai kuma don ya dace da shi daidai a ƙarin lokuta. bAn sauya mulkin Bruun sau da yawa don lissafin jigilar kaya, overwash, da jigilar sediment Aeolian.**' Misali, Dean da Maurmeier a cikin 1983 sun canza dokar don ta dace da gabar shinge da tsibirai, wasu daga cikinsu suna fuskantar karuwa maimakon rushewa. Rosati et al. a cikin 2013  da Dean da Houston a cikin 2016  sun canza dokar don lissafin jigilar kaya, da kuma motsi na bakin teku a kan zurfin rufewa. Bugu da ƙari, Ashton et al. a cikin 2011 sun canza dokar Bruun don amfani a kan tsaunuka masu tsawo, kuma Hinkel et al. A cikin 2013 sun yi amfani da dokar a matsayin wani ɓangare na hanyar da ta fi dacewa don bayyana tasirin hauhawar matakin teku a kan da kewayen hanyoyin shiga ruwa. Babban ƙalubalen da ya rage yana da alama yana ware tasirin hauhawar matakin teku a kan yanayin rairayin bakin teku daga tasirin tasirin tasirin raƙuman ruwa, ruwan sama, aikin iska, kayan ɗaki, nau'ikan ɗaki da girman hatsi, da sauransu.

A cikin nau'o'i daban-daban kuma haɗe da wasu samfuran, yanzu an yi amfani da dokar Bruun don kimanta martani na bakin teku ga hauhawar matakin teku a duk duniya. An yi amfani da mulkin Bruun ga gabar teku ciki har da Tekun Caspian,  Koriya ta Koriya,  Shuidong Bay,  Norfolk,  Rhode Island,  Florida,  Accra, [5] da Hawaii. [5]

## Tattaunawa
Tasirin Canjin yanayi a kan rairayin bakin teku yana da ƙalubale ga yin samfurin daidai, saboda batun ne wanda ya haɗa da teku, ƙasa, da kimiyyar yanayi da kuma aikin injiniya da manufofi. Ana buƙatar kimantawa mai aminci na tasirin sauyin yanayi na bakin teku don tallafawa ingantaccen dabarun daidaitawa don shirya al'ummomin bakin teku masu girma da dukiyar bakin teku masu daraja. A sakamakon haka, ana ci gaba da nazarin samfuran don kimanta lalacewar bakin teku sakamakon hauhawar matakin teku - gami da mulkin Bruun da samfuran da suka danganci mulkin Bruun - ana sabunta su akai-akai. Dokar Bruun ta zama cibiyar muhawara mai yawa ta ilimi.

Dangane da tunanin da aka samo asali, an soki mulkin Bruun sosai.**' Wasu daga cikin ra'ayoyin da aka fi sukar su sun haɗa da rashin kasancewa da gradients a cikin jigilar sediment mai tsawo, kasancewar zurfin rufewa, kasafin kuɗi mai rufewa, da kuma wadatar isasshen tushen [[yashi]]. A cikin 2015, Andersen et al. sun lakafta mulkin Bruun a matsayin "da kansa... kusan ba za a iya amfani da shi ba a cikin yanayin bakin teku"  saboda tunaninsa na yanayin [[Yanayi na halitta|muhalli na zahiri]]. 

Ɗaya daga cikin abubuwan da aka soki game da mulkin Bruun shine ka'idarsa game da tasirin tasirin sufuri na dogon lokaci a matsayin abin da ba a kula da shi ba,    kamar yadda dokar ta hanyar ma'anar samfurin giciye na biyu wanda ba ya lissafin girman na uku na dogon lokaci.  Wadannan tasirin tsaunuka na iya, duk da sauka, zama babban dalilin rushewar laka ko saukowa tare da rairayin bakin teku, mamaye yanayin bakin teku har ma da rufe tasirin hauhawar matakin teku kamar yadda Bruun Model ya bayyana.

Wani zato da aka soki shi ne kasancewar 'zurfin rufewa'. Ana ɗaukar zurfin rufewa a matsayin zurfin ruwa wanda babu canje-canje masu mahimmanci a matakin gado, kuma yawanci ana ɗaukar shi azaman iyaka tsakanin bakin teku na sama, wanda ke nuna raƙuman ruwa da sanduna, da ƙananan bakin teku, wanda ke da raƙuman da ba su karya ba da kuma rashin sanduna.  Dokar Bruun ta tsara cewa babu wani canjin turɓaya mai mahimmanci a fadin wannan iyaka, duk da haka ana muhawara game da ƙarfin wannan ra'ayi a aikace. Sauran samfurin R-DA, wanda Davidson-Arnott ya gabatar,  ya dogara ne akan irin wannan zato kamar mulkin Bruun, sai dai ya gane muhimmiyar canja wurin sediment tsakanin saman da ƙananan bakin teku, yana zaton cewa sediment yana lalacewa daga ƙananan bakin teku kuma ana jigilar shi zuwa saman bakin teku don kula da bayanin daidaito, kuma a sakamakon haka akwai ƙaura zuwa sama da ƙasa na zurfin rufewa tare da hauhawar matakin teku.

Cooper da Pilkey sun kasance kai tsaye a cikin sukar da suka yi game da mulkin Bruun, suna buga takarda a cikin 2004 mai taken "Rashin matakin teku da koma baya na bakin teku: lokacin barin Dokar Bruun",  wanda aka ambata akai-akai a cikin wallafe-wallafen da suka biyo baya. Sun yi jayayya cewa duk da zargi da yawa, ana ci gaba da amfani da asalin Bruun a cikin mahallin da bai dace ba, kamar yadda Bruun  da tarihin gwaji suka tsara, kuma cewa mulkin Bruun da abubuwan da ke tattare da shi suna cikin samfuran da suka biyo baya suna da'awar bayar da ƙarin fahimta game da halayyar bakin teku. Cooper da Pilkey sun bayyana amfani da mulkin Bruun a matsayin "a "model daya dace da duka" hanyar" **''' zuwa kewayon rikitarwa bakin teku mahalli wanda bai dace da bayyanawa ba. Sun lissafa manyan dalilai guda uku cewa dokar "ba ta aiki":  ƙuntataccen zato, watsi da mahimman masu canji, da dogaro da tsoffin ra'ayoyin da ba daidai ba. Sun bayyana ƙuntataccen ra'ayi na doka a matsayin ma'auni na kayan rufewa, wanda ya yi watsi da jigilar kaya, da kuma rashin wani bangare mai yawa, wanda ke ɗauka hauhawar matakin teku koyaushe yana haifar da koma bayan rairayin bakin teku, wanda tare ya iyakance amfani da doka ga ƙananan bakin teku. Cooper da Pilkey sun lissafa masu canji da aka watsar a matsayin kasancewar outcrops ko low currents, tasirin gangaren shelf na nahiyar akan ƙimar koma baya, takamaiman alaƙar ra'ayoyin ra'ayi na bakin teku, da kuma sauye-sauye masu yawa na juyin halitta na bakin teku a ma'aunin lokaci, da kuma ra'ayoyi masu kuskure da aka dogara da su a matsayin ka'idar daidaitaccen bayanin maras kyau, zurfin rufewa, da kuma wannan ra'ayin da ba a goyan ra'ayin cewa ƙimar bakin teku yana da tasiri ga yawan koma baya. Sun "ƙayyade cewa [tsarin Bruun] ya wuce fa'idarsa kuma ya kamata a watsar da shi",  duk da haka an soki su saboda ba da "ma'anar madadin"  ga mulkin.

A cikin takardunsa,    Bruun bai gabatar da ƙididdigar lissafi mai tsauri ba don mulkinsa, wanda ya haifar da rikicewa a cikin al'ummar bincike.  Misali, Rosen a cikin 1978, Allison da Schwartz a cikin 1981, Dean da Maurmeyer a cikin 1983, da Zhang, Douglas da Leatherman a cikin 2004 duk sun samo mulkin Bruun daban, tare da rashin jituwa game da zato da iyakokin mulkin Bruun na musamman ga nasu abubuwan da suka samo asali. Koyaya, sake dubawa na ƙarshe na Zhang et al. ya gabatar da madadin da ke nuna cewa "ko da yake yana da sauƙi sosai, tsarin Bruun yana da yawa".

Wasu gwaje-gwaje na filin da na dakin gwaje- gwaje-gaje sun goyi bayan mulkin Bruun, kodayake an soki kuskuren gwaji a cikin waɗannan wallafe-wallafen. Daga cikin wasu, Ranasinghe da Stive a cikin 2009,  kuma daga baya Andersen et al. a cikin 2015,  sun kammala cewa "babu wani binciken da ya samar da cikakkiyar tabbatarwa game da samfurin Brunn". Koyaya, akwai kusan yarjejeniya cewa ainihin ƙirar ƙididdigar koma bayan bakin teku tana da inganci,   duk da yawa bayanan da aka tattara daga mulkin Bruun ana kiranta da "kimanin ƙididdiga mai yawa"  ko "ƙididdigar ƙididdiga". Duk da waɗannan zarge-zarge, ana yaba wa mulkin Bruun saboda sauƙin sa, kuma har yanzu "babu wani zaɓi mai sauƙi, mai yiwuwa".

## Manazarta