Yong'in - Wildfire

The Rim Fire 250 ming gektardan ortiq maydonni (1000 km) yondirdi²) ning o'rmon yaqin Yosemit milliy bog'i, 2013 yilda

A yong'in, yovvoyi yong'in yoki qishloq olovi hududidagi rejasiz, istalmagan, nazoratsiz yong'in yonuvchan o'simlik dan boshlab qishloq joylari va shahar joylari.^[1] Mavjud o'simlik turiga qarab, o'rmon yong'inini aniqroq o'rmon yong'inlari, cho'tka yong'inlari, o't yong'inlari (Avstraliyada ), cho'l yong'ini, o't o'tlari, tepaliklar olovi, torf yong'inlari, dasht o'tlari, o'simliklarning yong'inlari yoki veld olovlari.^[2] Ko'pgina tashkilotlar ko'rib chiqadi yong'in rejalashtirilmagan va istalmagan yong'in degani,^[3] esa yovvoyi o'tlar - bu belgilangan yong'in va yirtqichlardan foydalanishni o'z ichiga olgan kengroq atama (WFU; ular shuningdek, kuzatiladigan yong'inlar deb ataladi).^[3][4]

Fotoalbom ko'mir 420 million yil oldin quruqlikdagi o'simliklar paydo bo'lganidan ko'p o'tmay o'rmon yong'inlari boshlanganligini ko'rsatadi.^[5] Quruqlik hayoti davomida o'rmon yong'inlarining kelib chiqishi yong'in aksariyat ekotizimlar florasi va hayvonot dunyosiga evolyutsion ta'sir ko'rsatgan bo'lishi mumkin degan taxminni keltirib chiqaradi.^[6] Yer uglerodga boy o'simlik qoplami, mavsumiy quruq iqlim, atmosfera kislorodi va keng tarqalgan chaqmoq va vulqon otashlari tufayli o'z-o'zidan alangalanadigan sayyora.^[6]

O'rmon yong'inlari alangalanish sababi, ularning fizik xususiyatlari, mavjud bo'lgan yonuvchan material va ob-havoning olovga ta'siri jihatidan tavsiflanishi mumkin.^[7] O'rmon yong'inlari mol-mulkka va inson hayotiga zarar etkazishi mumkin, garchi tabiiy ravishda paydo bo'ladigan yong'inlar mahalliy o'simliklarga, hayvonlarga va olov bilan rivojlangan ekotizimlarga foydali ta'sir ko'rsatishi mumkin.^[8][9] O'rmon yong'inlari harakati va jiddiyligi mavjud bo'lgan yoqilg'i, jismoniy sharoit va ob-havo kabi omillarning kombinatsiyasidan kelib chiqadi.^{[10][11][12][13]} G'arbiy Shimoliy Amerikadagi tarixiy meteorologik ma'lumotlar va milliy yong'in yozuvlari tahlili shuni ko'rsatadiki, katta miqdordagi mintaqaviy yong'inlarni sezilarli darajada yoqilg'ini yaratadigan namlik davrida yoki qurg'oqchilik va iliqlashishda qulay ob-havo sharoitini kengaytiradigan yirik mintaqaviy yong'inlarni haydashda.^[14]

Yuqori darajadagi yong'in kelib chiqadi murakkab erta seral o'rmoni ko'pincha yoqilmagan eski o'rmonga qaraganda turlarning boyligi va xilma-xilligi yuqori bo'lgan yashash muhiti ("o'rmon o'rmonlari yashash joyi" deb ham ataladi). Ko'p o'simlik turlari o'sishi va ko'payishi uchun olov ta'siriga bog'liq.^[15] Yong'in tez-tez uchramaydigan yoki mahalliy bo'lmagan o'simlik qatlami ekosistemalaridagi o'rmon yong'inlari juda salbiy ekologik ta'sirga ega bo'lishi mumkin.^[7]

O'rmon yong'inlari ba'zi mintaqalarda, shu jumladan, tabiiy ofatlarning eng keng tarqalgan shakllaridan biridir Sibir, Kaliforniya va Avstraliya.^[16][17][18] Maydonlar O'rta er dengizi iqlimi yoki ichida taiga biom ayniqsa sezgir.

Sabablari

Media-ni ijro etish

Janubiy Amerika yong'inlarini bashorat qilish.

Media-ni ijro etish

UR Irvine olimi Jeyms Randerson okean harorati va yong'in mavsumi zo'ravonligini bog'laydigan yangi tadqiqotlarni muhokama qilmoqda.

Tabiiy

O'rmon yong'inlarining etakchi tabiiy sabablariga quyidagilar kiradi.^[19][20]

• quruq iqlim
• chaqmoq
• vulqon otilishi

Inson faoliyati

Odamzotning yong'in chiqishini eng keng tarqalgan sabablariga quyidagilar kiradi o't qo'yish, tashlangan sigaretalar, elektr uzatish liniyalari yoylar (tomonidan aniqlanganidek boshqlarni xaritalash ) va jihozlardan uchqunlar.^[21][22] Yovvoyi yong'inlarni issiq miltiq o'qlari bilan aloqa qilish orqali yoqish ham tegishli sharoitda mumkin.^[23] O'rmon yong'inlari boshdan kechirayotgan jamoalarda ham boshlanishi mumkin almashlab ekish, bu erda er tez tozalanadi va tuproq unumdorligini yo'qotguncha dehqonchilik qilinadi va qirqish va yoqish tozalash.^[24] Yog'ochni kesib tashlash bilan o'rmonzorlar yonuvchan o'tlarning ustunligini rag'batlantiradi va tashlab qo'yiladi yo'llarni kesish o'simlik tomonidan o'sib chiqqan o'tin yo'laklari vazifasini o'tashi mumkin. Janubda yillik o'tloq o'tlari Vetnam tomonidan o'rmonzorlarning yo'q qilinishidan qisman kelib chiqadi AQSh harbiylari paytida gerbitsidlar, portlovchi moddalar va erni tozalash va yoqish bo'yicha mexanik ishlar Vetnam urushi.^[25]

Tarqalishi

O'rmon yong'inlarining eng keng tarqalgan sababi butun dunyoda turlicha. Kanadada va Xitoyning shimoli-g'arbiy qismida chaqmoq yonishning asosiy manbai sifatida ishlaydi. Dunyoning boshqa qismlarida odamlarning ishtiroki katta hissa qo'shadi. Afrika, Markaziy Amerika, Fidji, Meksika, Yangi Zelandiya, Janubiy Amerika va Janubi-Sharqiy Osiyoda o'rmon yong'inlari qishloq xo'jaligi, chorvachilik va erni konversiyani yoqish. Xitoyda va O'rta er dengizi havzasi, odamlarning ehtiyotsizligi o'rmon yong'inlarining asosiy sababidir.^[26][27] Qo'shma Shtatlar va Avstraliyada o'rmon yong'inlari manbai chaqmoq urishida ham, odamlarning xatti-harakatlarida ham kuzatilishi mumkin (masalan, mashinalar uchqunlari, tashlangan sigaret qoldiqlari yoki o't qo'yish ).^[28][29] Ko'mir qatlamining yong'inlari dunyodagi minglab odamlarga yoqib yuboring, masalan Yonayotgan tog ', Yangi Janubiy Uels; Markaziy, Pensilvaniya; va bir nechta Xitoyda ko'mir yoqadigan yong'inlar. Ular, shuningdek, kutilmaganda alangalanishi va yaqin atrofdagi yonuvchan materialni yoqib yuborishi mumkin.^[30]

Britaniya Kolumbiyasidagi odamlarning qo'zg'atadigan yong'inlari 40% ni tashkil qiladi va bu ochiq yoqish, dvigatellardan yoki transport vositalaridan foydalanish, yonib turgan sigaretalar kabi moddalarni tashlab yuborish yoki uchqun yaratishi mumkin bo'lgan har qanday boshqa inson faoliyati bilan bog'liq. yoki yong'inni yoqish uchun etarli bo'lgan issiqlik manbai.^[31] 2019 yilda Britaniya Kolumbiyasida yuzlab yong'inlar yonmoqda va ularning to'rtdan bir qismi odamlar tomonidan sodir bo'ldi.^[32]

Tarqalish

Ning g'arbiy cho'lida yuzaki yong'in Yuta, Qo'shma Shtatlar

Olovda toj yong'inidan keyin charxlangan manzara Shimoliy kaskadlar, Qo'shma Shtatlar

Uzoqdan ko'rinadigan o'rmon yong'inlari Dajti milliy bog'i, Tirana, Albaniya

Yong'inlarning tarqalishi mavjud bo'lgan yonuvchan material, uning vertikal joylashishi va namligi va ob-havo sharoitlariga qarab o'zgaradi.^[33] Yoqilg'i tartibi va zichligi qisman boshqariladi topografiya, chunki er shakli o'simliklarning o'sishi uchun mavjud quyosh nuri va suv kabi omillarni belgilaydi. Umuman olganda, yong'in turlari odatda yonilg'i bilan quyidagicha tavsiflanishi mumkin:

• Zamin yong'inlar er osti ildizlari bilan oziqlanadi, duff va boshqa ko'milgan organik moddalar. Ushbu yoqilg'i turi, ayniqsa, dog 'tushishi sababli alangalanishga sezgir. Erdagi yong'inlar, odatda, tutun bilan yonadi va bir necha kundan bir necha oygacha asta-sekin yonib ketishi mumkin torf yong'inlari yilda Kalimantan va Sharqiy Sumatra, Indoneziya natijasida paydo bo'lgan boylik yaratish loyihasi hijobni bilmasdan quritgan va quritgan.^[34][35][36]
• Emaklab yurish yoki sirt yong'inlar pastdagi o'simliklar tomonidan quvvatlanadi o'rmon tagligi barg va yog'och axlatlari, qoldiqlar, o'tlar va pastak butalar.^[37] Bunday yong'in ko'pincha toj yong'inlariga qaraganda nisbatan past haroratda yonadi (400 ° C dan kam (752 ° F)) va sekin tarqalishi mumkin, ammo tik yamaqlar va shamol tarqalish tezligini tezlashtirishi mumkin.^[38]
• Narvon yong'inlar past darajadagi o'simliklar va daraxt soyabonlari orasidagi materialni iste'mol qiladi, masalan, kichik daraxtlar, pastga tushgan loglar va uzumzorlar. Kudzu, Qadimgi dunyo toqqa chiqadigan fern va boshqalar invaziv o'simliklar shkaladagi daraxtlar, shuningdek, narvon yong'inlarini rag'batlantirishi mumkin.^[39]
• Toj, soyabon, yoki havo yong'inlar baland daraxtlar, uzumzorlar va moxlar singari osilgan materiallarni soyabon darajasida yoqib yuboradi. Toj olovining ateşlenmesi, deb nomlangan toj kiyish, to'xtatilgan materialning zichligi, soyabon balandligi, soyabonning uzluksizligi, sirt va narvonlarning etarli darajada yong'inlari, o'simliklarning namligi va olov paytida ob-havo sharoitlariga bog'liq.^[40] Odamlar tomonidan yoqilgan stend o'rnini bosuvchi yong'inlar tarqalishi mumkin Amazon yomg'ir o'rmoni, zararli ekotizimlar, ayniqsa issiqlik yoki quruq sharoitga mos kelmaydi.^[41]

Avstraliyaning shimolidagi mussonli hududlarda sirtdan yong'inlar tarqalishi mumkin, shu jumladan mo'ljallangan o't o'chirish joylari bo'ylab, o'tin parchalarini yoqish yoki tutashtirish yoki o'rmon yong'inlari bilan yuvib tashlangan yirtqichni ushlashga odatlangan yirik uchuvchi qushlar tomonidan qasddan olib o't o'tlari. Ushbu turlar Black Kite (Milvus migranslari ), Hushtakboz uçurtma (Haliastur sphenurus ) va Brown Falcon (Falco berigora ). Mahalliy Mahalliy aholi bu xatti-harakatlar haqida uzoq vaqtdan beri bilishadi, shu jumladan ularning mifologiya.^[42]

Jismoniy xususiyatlar

Eksperimental yong'in Kanada

Kirli yo'l yong'in to'sig'i bo'lib xizmat qildi Janubiy Afrika. To'siqning ta'sirini yo'lning yonmagan (chapda) va kuygan (o'ng) tomonlarida aniq ko'rish mumkin.

O'rmon yong'inlari yong'in uchirish kuchining barcha kerakli elementlari sezgir joyda birlashganda paydo bo'ladi: tutashuv manbai, masalan, yonuvchan material bilan aloqa qilganda o'simlik, bu etarli darajada issiqlikka ta'sir qiladi va atrof-muhit havosidan etarli miqdorda kislorod bilan ta'minlanadi. Yuqori namlik odatda alangalanishni oldini oladi va tarqalishini sekinlashtiradi, chunki materialdagi har qanday suvni bug'langanda va materialni unga qizdirishda yuqori harorat kerak bo'ladi yong'in nuqtasi.^[12][43] Zich o'rmonlar odatda ko'proq soyalarni beradi, natijada atrof-muhit harorati pasayadi va kattaroq bo'ladi namlik, va shuning uchun o'rmon yong'inlariga kam ta'sir ko'rsatadi.^[44] Maysalar va barglar kabi kamroq zichroq materialni yoqish osonroq, chunki ular tarkibida shoxlar va magistrallar kabi zichroq materiallarga qaraganda kamroq suv bor.^[45] O'simliklar doimiy ravishda suv yo'qotadi evapotranspiratsiya, lekin suv yo'qotilishi odatda tuproqdan, namlikdan yoki yomg'irdan so'rilgan suv bilan muvozanatlanadi.^[46] Ushbu muvozanat saqlanmasa, o'simliklar quriydi va shuning uchun ular tezroq alangalanadi, ko'pincha bu qurg'oqchilikning natijasidir.^[47][48]

Yong'in old bu doimiy yonib turadigan yonishni ta'minlaydigan qism, bu erda yonmagan material faol alangaga to'g'ri keladi yoki tutun yonmagan va yoqilgan materiallar orasidagi o'tish.^[49] Oldinga yaqinlashganda, olov atrofdagi havoni ham, yog'ochli materialni ham isitadi konvektsiya va termal nurlanish. Birinchidan, yog'och 100 ° C (212 ° F) haroratda bug'langanda quritiladi. Keyingi, piroliz 230 ° C (450 ° F) darajadagi o'tin yonuvchan gazlarni chiqaradi. Va nihoyat, yog'och 380 ° C (720 ° F) da tutun chiqishi yoki etarlicha qizdirilganda 590 ° C (1000 ° F) da yonishi mumkin.^[50][51] O'rmon yong'inlari ma'lum bir joyga etib borishdan oldin ham, issiqlik uzatish yong'in oldidan havoni 800 ° C (1,470 ° F) ga qadar isitadi, bu esa yonuvchan materiallarni oldindan qizdiradi va quritadi, bu materiallarning tezroq yonishini keltirib chiqaradi va olov tez tarqalishiga imkon beradi.^[45][52] Yuqori harorat va uzoq davom etadigan sirtdagi yong'inlar rag'batlantirishi mumkin yorilish yoki mash'al qilish: quritish daraxt soyabonlari va ularni keyinchalik pastdan yoqish.^[53]

O'rmon yong'inlari tezda mavjud oldinga tarqalish darajasi (FROS) zich uzluksiz yoqilg'ida yoqilganda.^[54] Ular o'rmonlarda soatiga 10,8 kilometr (6,7 milya) va o'tloqlarda soatiga 22 kilometr (14 milya) tezlikda harakatlana olishadi.^[55] O'rmon yong'inlari a shakllanishi uchun asosiy jabhaga tegib o'tishi mumkin yonboshlash old tomonga yoki asosiy old tomonga qarama-qarshi yo'nalishda yoqib yuboring qo'llab-quvvatlash.^[56] Ular shuningdek tarqalishi mumkin sakrash yoki aniqlash shamol va vertikal sifatida konvektsiya ustunlar olib yurishadi o't o'chiruvchilar (issiq o'tin o'tlari) va boshqa yonuvchi materiallar havo orqali yo'llar, daryolar va aks holda harakat qilishi mumkin bo'lgan boshqa to'siqlar orqali o't o'chirish.^[57][58] Daraxt soyabonlaridagi mash'ala va yong'inlar aniqlanishni rag'batlantiradi va o'rmon yong'inlari atrofida quruq yoqilg'ilar yoqilg'ida yong'in chiqa olmaydi.^[59] Spotting yaratishi mumkin yong'inlar olov yoqilganda yoqilg'ini yoqib yuboradigan issiq olov va olovli brendlar. Yilda Avstraliya yong'inlari, aniq yong'inlar yong'in oldidan 20 kilometr (12 milya) uzoqlikda sodir bo'lishi ma'lum.^[60]

Katta, to'xtovsiz yong'inlarning paydo bo'lishi Shimoliy Amerika so'nggi yillarda ko'payib, ikkalasiga ham sezilarli ta'sir ko'rsatmoqda shahar va qishloq xo'jaligiga yo'naltirilgan joylar. Nazorat qilinmagan yong'inlar natijasida qolgan jismoniy zarar va sog'liq uchun bosim, ayniqsa, fermer xo'jaligini vayron qildi chorvachilik ta'sirlangan hududlardagi operatorlar, jamoatchilikni tashvishga solmoqda Sog'liqni saqlash ushbu ixtisoslashgan kasb aholisiga xizmat ko'rsatuvchi provayderlar va advokatlar.^[61]

Ayniqsa, katta o'rmon yong'inlari yaqin atrofdagi havo oqimlariga ta'sir qilishi mumkin stek effekti: havo qizdirilganda ko'tariladi va katta yong'inlar kuchli quvvatga ega yangilanishlar shunday bo'ladi chizish yaqin atrofdagi yangi, salqin havo termal ustunlar.^[62] Harorat va namlikdagi katta vertikal farqlar rag'batlantiradi pirokumulus bulutlari, kuchli shamol va olov girdoblari tornado kuchi bilan soatiga 80 kilometrdan ko'proq tezlikda (50 milya).^[63][64][65] Tez tarqalish tezligi, samarali toj kiyish yoki dog'lanish, yong'in girdoblari mavjudligi va kuchli konvektsiya ustunlari o'ta og'ir sharoitlarni anglatadi.^[66]

O'rmon yong'inidan kelib chiqadigan issiqlik harorati sezilarli darajada olib kelishi mumkin ob-havo toshlar va toshlar, issiqlik tezda toshni kengaytirishi va termal zarba sodir bo'lishi mumkin, bu ob'ektning tuzilishini buzishiga olib kelishi mumkin.

Iqlimning ta'siri

Yozning quruq mavsumida chaqmoq chaqnagan o'rmon yong'inlari tez-tez uchrab turadi Nevada.

Yong'in Venesuela qurg'oqchilik paytida

Issiqlik to'lqinlari, qurg'oqchilik, iqlim o'zgaruvchanligi kabi El-Nino va yuqori bosimli tizmalar kabi mintaqaviy ob-havo sharoiti xavfni oshirishi va o'rmon yong'inlari xatti-harakatlarini keskin o'zgartirishi mumkin.^[67][68][69] Yog'ingarchilik yillari, so'ngra iliq davrlar yong'inlarning keng tarqalishiga va uzoq muddatli olovlarni rag'batlantirishi mumkin.^[70] 1980-yillarning o'rtalaridan boshlab, qorlarning erishi va shu bilan bog'liq isish, shuningdek, o'rmon yong'inlari mavsumining davomiyligi va zo'ravonligining oshishi yoki yilning eng ko'p yong'in sodir bo'lishi bilan bog'liq edi,^[71] ichida G'arbiy Amerika Qo'shma Shtatlari.^[72] Global isish ko'plab hududlarda qurg'oqchilikning intensivligi va chastotasini ko'paytirishi, shiddatli va tez-tez yong'inlarni keltirib chiqarishi mumkin.^[7] 2019 yilgi tadqiqot shuni ko'rsatadiki, o'sish Kaliforniyada yong'in xavfi ga tegishli bo'lishi mumkin inson tomonidan kelib chiqadigan iqlim o'zgarishi.^[73] Tadqiqot allyuvial cho'kindi 8000 yildan oshiq vaqtga cho'zilgan konlar iliqroq iqlim davrida qattiq qurg'oqchilik va o'rnini bosuvchi yong'inlarni boshdan kechirganligi va iqlimning o'rmon yong'inlariga ta'siri shunchalik kuchli ediki, oldindan istiqbolli o'rmon tuzilishini tiklashga urinish iliqroq kelajakda mumkin emas.^[74]

Kunduzgi soatlarda intensivlik ham oshadi. Yonayotgan jurnallarning kuyish tezligi kun davomida namlikning pastligi, haroratning oshishi va shamol tezligining oshishi sababli besh baravar ko'p.^[75] Quyosh nurlari kun davomida erni isitadi, bu esa tepalikka qarab harakatlanadigan havo oqimlarini hosil qiladi. Kechasi quruqlik soviydi, pastga tushadigan havo oqimlari hosil bo'ladi. O'rmon yong'inlari bu shamollardan g'azablanmoqda va ko'pincha tepaliklar va vodiylar bo'ylab havo oqimlarini kuzatib boradi.^[76] Evropada yong'inlar soat 12:00 da tez-tez yuz beradi. va soat 14:00 da^[77] Qo'shma Shtatlarda o'rmon yong'inlarini o'chirish ishlari 24 soat atrofida davom etadi olov kuni kunduzgi issiqlik natijasida yuzaga keladigan intensivlikning taxmin qilinadigan o'sishi tufayli soat 10:00 da boshlanadi.^[78]

2019 yilda haddan tashqari issiqlik va quruqlik katta o'rmon yong'inlarini keltirib chiqardi Sibir, Alyaska, Kanareykalar orollari, Avstraliya va Amazon yomg'ir o'rmonlari. Ikkinchisidagi yong'inlar, asosan, daraxtlarni noqonuniy ravishda kesish natijasida sodir bo'lgan. Yong'inlarning tutuni ulkan hududlarda, shu jumladan yirik shaharlarda kengayib, havo sifatini keskin pasaytirdi.^[79]

2020 yil avgust holatiga ko'ra, o'rmon yong'inlari 2019 yilga nisbatan 13 foizga yomonroq bo'lgan. Iqlim o'zgarishi va O'rmonlarni yo'q qilish asosiy sababdir. CO2 chiqindilari atmosfera chiqindilariga teng edi Yevropa Ittifoqi. Yong'inlar mavjud bo'lishiga tahdid solmoqda Amazon yomg'ir o'rmonlari. WWF-UK-ning Fan va tabiatni muhofaza qilish bo'yicha ijrochi direktori Mayk Barretning so'zlariga ko'ra, agar ushbu tropik o'rmon yo'q qilinsa "biz iqlim o'zgarishiga qarshi kurashni yo'qotamiz. Orqaga qaytish bo'lmaydi".^[80]

Emissiya

O'rmon yong'inlari atmosferaga ko'p miqdordagi karbonat angidrid, qora uglerod, jigarrang uglerod va ozon prekursorlarini chiqaradi. Ushbu chiqindilar mintaqaviy va hatto global miqyosda radiatsiya, bulutlar va iqlimga ta'sir qiladi. O'rmon yong'inlari shuningdek ozon va organik zarrachalar hosil qiluvchi uchuvchan va yarim uchuvchan organik materiallar va azot oksidlarini chiqaradi. Zaharli ifloslantiruvchi moddalarning to'g'ridan-to'g'ri chiqindilari birinchi javob beruvchilarga va mahalliy aholiga ta'sir qilishi mumkin. Bundan tashqari, havo tashilayotganda boshqa ifloslantiruvchi moddalarning paydo bo'lishi o'rmon yong'inlaridan uzoqda joylashgan hududlarda aholi uchun zararli ta'sirga olib kelishi mumkin.^[81] O'rmon yong'inlari chiqindilari mahalliy va mintaqaviy havo sifatiga ham ta'sir qiladi.^[82]

Ekologiya

2008 yil davomida avgust (yuqori rasm) va fevral (pastki rasm) oylarida sodir bo'lgan global yong'inlar O'rtacha piksellar sonini ko'rish spektroradiometr (MODIS) NASA-da Terra sun'iy yo'ldoshi.

Quruqlik hayoti davomida o'rmon yong'inining paydo bo'lishi yong'in aksariyat ekotizimlar florasi va hayvonot dunyosiga evolyutsion ta'sir ko'rsatgan bo'lishi mumkin degan taxminni keltirib chiqaradi.^[6] Yovvoyi yong'inlar o'simliklarning o'sishiga imkon beradigan darajada nam bo'lgan, ammo quruq va issiq davrlarda davom etadigan iqlim sharoitida keng tarqalgan.^[15] Bunday joylarga Avstraliya va Janubi-sharqiy Osiyo, veld Afrikaning janubida, fynbos Janubiy Afrikaning G'arbiy Cape qismida, AQSh va Kanadaning o'rmonli hududlari va O'rta er dengizi havzasi.

Yuqori darajadagi yong'in kelib chiqadi murakkab erta seral o'rmoni ko'pincha yoqilmagan eski o'rmonga qaraganda turlarning boyligi va xilma-xilligi yuqori bo'lgan yashash muhiti ("o'rmon o'rmonlari yashash joyi" deb ham ataladi).^[8] Shimoliy Amerika o'rmonlarining aksariyat turlarida o'simlik va hayvonot turlari yong'in bilan rivojlangan va bu turlarning ko'pi ko'payish va o'sish uchun o'rmon yong'inlariga, xususan, yuqori darajadagi yong'inlarga bog'liq. Yong'in o'simlik moddasidan ozuqa moddalarini tuproqqa qaytarishga yordam beradi, olovdan olinadigan issiqlik ba'zi turdagi urug'larning unib chiqishi uchun zarurdir va yuqori zo'ravonlik yong'inlari natijasida hosil bo'lgan chayqalishlar (o'lik daraxtlar) va erta ketma-ket o'rmonlar foydali bo'lgan yashash sharoitlarini yaratadi. yovvoyi hayotga.^[8] Yuqori darajadagi yong'in natijasida hosil bo'lgan dastlabki ketma-ket o'rmonlar mo''tadil ignabargli o'rmonlarda mavjud bo'lgan mahalliy biologik xilma-xillikning eng yuqori darajasini qo'llab-quvvatlaydi.^[9][83] Yong'in chiqindilarini kesish ekologik foyda keltirmaydi va ko'plab salbiy ta'sirlarni keltirib chiqaradi; ko'pincha o'tdan keyin ekish uchun ham xuddi shunday.^[84]

Garchi ba'zi ekotizimlar o'sishni tartibga solish uchun tabiiy ravishda paydo bo'ladigan yong'inlarga ishonsa ham, ba'zi ekotizimlar juda ko'p olovdan aziyat chekmoqda, masalan chaparral yilda Kaliforniya janubi va Amerikaning janubi-g'arbiy qismida past balandlikdagi cho'llar. Odatda yong'inga bog'liq bo'lgan ushbu hududlarda yong'in chastotasining ko'payishi tabiiy tsikllarni buzdi, mahalliy o'simliklarga zarar etkazdi va mahalliy bo'lmagan begona o'tlarning ko'payishini rag'batlantirdi.^{[85][86][87][88]} Invaziv turlar, kabi Ligodium mikrofilum va Bromus tectorum, yong'in natijasida zarar ko'rgan joylarda tez o'sishi mumkin. Ular juda alangali bo'lgani uchun, kelajakda yong'in xavfini oshirishi mumkin, a ijobiy teskari aloqa davri bu yong'in chastotasini oshiradi va tabiiy o'simlik jamoalarini yanada o'zgartiradi.^[39][89]

In Amazon yomg'ir o'rmoni, qurg'oqchilik, daraxtlarni kesish, chorvachilik amaliyoti va yonib ketish qishloq xo'jaligi olovga chidamli o'rmonlarga zarar etkazadi va yonuvchan cho'tkaning o'sishiga yordam beradi, bu esa ko'proq yonishni rag'batlantiradigan tsikl yaratadi.^[90] Yomg'ir o'rmonidagi yong'inlar uning xilma-xil turlari kollektsiyasiga tahdid soladi va ko'p miqdorda CO hosil qiladi₂.^[91] Shuningdek, yomg'ir o'rmonidagi yong'inlar, qurg'oqchilik va odamlarning ishtiroki bilan 2030 yilga kelib Amazon o'rmonlarining yarmidan ko'piga zarar etkazishi yoki yo'q qilishi mumkin.^[92] O'rmon yong'inlari kul hosil qiladi, organik ozuqa moddalarining mavjudligini kamaytiradi va suv oqimi ko'payishiga olib keladi, boshqa oziq moddalarni yo'q qiladi va hosil qiladi toshqin toshqini shartlar.^[33][93] 2003 yildagi yong'in Shimoliy Yorkshirdagi Murlar ning 2,5 kvadrat kilometr (600 akr) maydonida yonib ketgan xezer va asosiy narsa torf qatlamlar. Keyinchalik, shamol eroziyasi kul va ochiq tuproqni tozalab, miloddan avvalgi 10000 yilgacha bo'lgan arxeologik qoldiqlarni aniqladi.^[94] O'rmon yong'inlari iqlim o'zgarishiga ham ta'sir qilishi, atmosferaga chiqadigan uglerod miqdorini ko'paytirishi va o'simliklarning o'sishini inhibe qilishi mumkin, bu o'simliklar tomonidan uglerodni umumiy qabul qilishiga ta'sir qiladi.^[95]

Yilda tundra o'simlik va tabiatiga qarab turlicha bo'lgan yoqilg'i va o'rmon yong'inlarining to'planishining tabiiy sxemasi mavjud. Alyaskadagi tadqiqotlar shuni ko'rsatdiki, yong'in hodisalarining qaytish oralig'i (FRI), odatda 150 dan 200 yilgacha o'zgarib turadi, qurigan pasttekislik joylari tog'li hududlarga qaraganda tez-tez yonib turadi.^[96]

O'simliklarni moslashtirish

Ekologik merosxo'rlik a yong'inidan keyin qarag'ay o'rmoni Hara Bog yonida, Lahemaa milliy bog'i, Estoniya. Suratlar olovdan bir va ikki yil o'tgach olingan.

Yong'in xavfi yuqori bo'lgan o'simliklar ekotizimlar ko'pincha mahalliylarga moslashish orqali omon qoladi yong'in rejimi. Bunday moslashuvlarga issiqdan jismoniy himoya qilish, yong'in sodir bo'lganidan keyin o'sishning ko'payishi va olovni rag'batlantiradigan va yo'q qilishi mumkin bo'lgan yonuvchan materiallar kiradi musobaqa. Masalan, turkumga mansub o'simliklar Evkalipt tarkibida olov va qattiqlikni rag'batlantiradigan yonuvchan yog'lar mavjud sklerofil issiqlikka va qurg'oqchilikka qarshi turadigan barglar, ularning kamroq olovga chidamli turlari ustidan ustunligini ta'minlaydi.^[97][98] Zich po'stlog'i, quyi shoxlarini to'kib tashlashi va tashqi tuzilmalardagi suv miqdori ko'pligi daraxtlarni haroratni ko'tarilishidan himoya qilishi mumkin.^[15] Olovga chidamli urug'lar va zaxira o'qqa tutmoqda yong'indan keyin unib chiqqan o'simliklar o'z ichiga olgan turlarning saqlanishini rag'batlantiradi kashshof turlar. Tutun, yoqilgan o'tin va issiqlik deb ataladigan jarayonda urug'larning unib chiqishini rag'batlantirishi mumkin serotin.^[99] Yonayotgan o'simliklarning tutuniga ta'sir qilish yordam beradi nihol apelsin ishlab chiqarishni qo'zg'atish orqali o'simliklarning boshqa turlarida butenolid.^[100]

G'arbda o'tloqlar Sabah, Malayziya qarag'ay o'rmonlar va Indoneziya Kasuarina O'rmonlar avvalgi yong'in davrlaridan kelib chiqqan deb hisoblashadi.^[101] Chamise o'lik daraxtlar axlati tarkibida suv kam va yonuvchan bo'lib, buta tezda olovdan keyin unib chiqadi.^[15] Cape nilufarlari alangalar qopqoqni yo'q qilguncha va keyin deyarli bir kechada gul ochguncha uxlamay yotishadi.^[102] Sequoia raqobatni kamaytirish uchun davriy yong'inlarga ishonish, ulardan urug'larni chiqarish konuslar, va yangi o'sish uchun tuproqni va soyabonni tozalang.^[103] Karib qarag'ay yilda Bagama tokzorlari tirik qolish va o'sish uchun past intensivlikdagi, sirtqi yong'inlarga moslashgan va unga tayangan. O'sish uchun optimal yong'in chastotasi har 3 yildan 10 yilgacha. Juda tez-tez yong'inlar yoqadi otsu o'simliklar Va kamdan-kam uchraydigan yong'inlar odatdagi turlarni yoqtiradi Bagama quruq o'rmonlari.^[104]

Atmosfera ta'siri

A Pirokumulus buluti yilda yong'in chiqardi Yellowstone milliy bog'i

Yer ob-havosi va havoning ifloslanishining katta qismi troposfera, atmosferaning sayyora yuzasidan taxminan 10 kilometr balandlikka (6 milya) cho'zilgan qismi. Qattiq momaqaldiroqning vertikal ko'tarilishi yoki pirokumulonimbus tutun, kuyikish va boshqalarni qo'zg'atishi mumkin bo'lgan katta yong'in hududida kuchaytirilishi mumkin zarrachalar pastki darajagacha baland stratosfera.^[105] Ilgari, stratosferadagi zarrachalarning aksariyati kelib chiqqan degan hukmron ilmiy nazariya mavjud edi vulqonlar, ammo quyi stratosferadan tutun va boshqa yong'in chiqindilari aniqlandi.^[106] Pirokumulus bulutlari o'rmon yong'inlari paytida 6100 metrga (20000 fut) yetishi mumkin.^[107] O'rmon yong'inlaridan kelib chiqqan tutun tutunlarini sun'iy yo'ldosh orqali kuzatish shuni ko'rsatdiki, 1600 kilometr (1000 mil) dan oshiq masofada shilimshiqlarni izsiz qoldirish mumkin.^[108] Kabi kompyuter yordamida ishlaydigan modellar KALPUFF yordamida o'rmon yong'inidan kelib chiqadigan tutun tutunlarining hajmi va yo'nalishini taxmin qilishga yordam beradi atmosfera dispersiyasini modellashtirish.^[109]

O'rmon yong'inlari mahalliy atmosfera ifloslanishiga ta'sir qilishi mumkin,^[110] va uglerodni karbonat angidrid shaklida chiqaring.^[111] O'rmon yong'inlari chiqindilari yurak-qon tomir va nafas olish muammolarini keltirib chiqaradigan mayda zarrachalarni o'z ichiga oladi.^[112] Troposferadagi yong'in mahsulotlarining ko'payishi ozon kontsentratsiyasini xavfsiz darajadan oshirishi mumkin.^[113] 1997 yilda Indoneziyadagi o'rmon yong'inlari 0,81 dan 2,57 gigacha bo'lgan deb taxmin qilingantonna (0,89 va 2,83 mlrd qisqa tonna ) CO₂ atmosferaga, ya'ni qazib olinadigan yoqilg'ini yoqish natijasida yillik karbonat angidrid chiqindilarining 13% dan 40% gacha.^[114][115]CAMS tahliliga ko'ra, 2019 yil iyun va iyul oylarida Arktikadagi yong'inlar 140 megatondan ortiq karbonat angidrid chiqardi. Buni istiqbolga qaratsak, bu yiliga 36 million avtomobil chiqaradigan uglerod miqdoriga teng. Yaqinda sodir bo'lgan o'rmon yong'inlari va ularning katta miqdordagi CO2 chiqindilari, parnik gazini kamaytirish maqsadlariga erishish bo'yicha chora-tadbirlarni amalga oshirishda ularni hisobga olish muhimligini anglatadi. Parij iqlim shartnomasi.^[116] Atmosferada yong'in tutunini tashish paytida yuzaga keladigan murakkab oksidlovchi kimyo tufayli,^[117] chiqindilarning toksikligi vaqt o'tishi bilan oshishi ko'rsatilgan edi.^[118][119]

Atmosfera modellari shuni ko'rsatadiki, bu zararli zarrachalarning kontsentratsiyasi kiruvchi moddalarning so'rilishini kuchaytirishi mumkin quyosh radiatsiyasi qish oylarida 15% gacha.^[120] Amazonda taxminan 90 milliard tonna uglerod borligi taxmin qilinmoqda. 2019 yilga kelib, er atmosferasi million uglerodga 415 qismdan iborat bo'lib, Amazonning yo'q qilinishi millionga 38 qismni qo'shadi.^[121]

Qo'shma Shtatlardagi er osti suvlari va tuproq namligining milliy xaritasi. Bu 2011 yong'in mavsumi bilan bog'liq tuproq namligining juda pastligini ko'rsatadi Texas.

Yon tomonga qarab turganingizda ko'ringan olovdan tutun izi Dargo dan Sviftlar Kriki, Viktoriya, Avstraliya, 2007 yil 11 yanvar

Tarix

Elk hammom, Elkning o'rmon yong'inidan saqlanishining fotosurati Montana

O'rmon yong'inlarining birinchi dalilidir riniofitoid sifatida saqlanib qolgan o'simlik qoldiqlari ko'mir ichida topilgan Uels chegaralari, bilan tanishish Siluriya davr (taxminan 420 million yil oldin). Yonayotgan er yuzidagi yong'inlar erta boshlanishidan biroz oldin sodir bo'la boshladi Devoniy davr 405 million yil oldin. O'rta va oxirgi Devon davrida kam atmosfera kislorodi ko'mir ko'pligining pasayishi bilan birga kechdi.^[122][123] Qo'shimcha ko'mir dalillari shuni ko'rsatadiki, yong'inlar davom etgan Karbonli davr. Keyinchalik, kech devonda atmosfera kislorodining umumiy o'sishi 13% dan 30-31% gacha Kechki Permian o'rmon yong'inlarining yanada keng tarqalishi bilan birga bo'lgan.^[124] Keyinchalik, o't o'chirishga bog'liq bo'lgan ko'mir konlarining kamayishi Permning oxiridan to oxirigacha Trias davrlar kislorod darajasining pasayishi bilan izohlanadi.^[125]

Paleozoy va mezozoy davridagi o'rmon yong'inlari hozirgi zamonda sodir bo'layotgan yong'inlarga o'xshab ketmoqda. Quruq fasllar ta'sirida yuzaki yong'inlar^{[tushuntirish kerak ]} devon va karbon davrlarida yaqqol namoyon bo'ladi progimnosperm o'rmonlar. Lepidodendron karbon davriga oid o'rmonlarda cho'qqilar ko'tarilib, toj yong'inlarining dalilidir. Yura davrida gimnosperm o'rmonlar, yuqori chastotali, engil sirtli yong'inlarning dalillari mavjud.^[125] Kechqurun yong'in faolligining oshishi Uchinchi darajali^[126] ehtimol ortishi bilan bog'liq C₄ -tip o'tlar. Sifatida bu o'tlar ko'proq o'tdi mezik yashash joylari, ularning yuqori yonuvchanligi yong'in chastotasini oshirdi va o'rmonzorlar ustida o'tloqlarni targ'ib qildi.^[127] Biroq, yong'inga moyil bo'lgan yashash joylari avlodlar singari daraxtlarning mashhur bo'lishiga hissa qo'shgan bo'lishi mumkin Evkalipt, Pinus va Sequoia yong'inlarga bardosh beradigan va ish bilan ta'minlaydigan qalin qobig'i bor piriskans.^[128][129]

Inson ishtiroki

Qasddan qilingan yong'inlarning havodan ko'rinishi Khun Tan tizmasi, Tailand. Ushbu yong'inlar ma'lum bir qo'ziqorinning o'sishiga yordam berish uchun har yili mahalliy fermerlar tomonidan yoqiladi

Odam tomonidan olovdan qishloq xo'jaligi va ov maqsadlarida foydalanish Paleolit va Mezolit yoshi avvalgi manzaralarni va yong'in rejimlarini o'zgartirdi. O'rmonzorlar asta-sekin sayohat, ov qilish, urug 'yig'ish va ekishni engillashtiradigan kichik o'simliklar bilan almashtirildi.^[130] Insoniyatning yozib olingan tarixida o'rmon yong'inlari haqida kichik ishora zikr etilgan Injil kabi mumtoz yozuvchilar tomonidan Gomer. Biroq, qadimgi ibroniy, yunon va rim yozuvchilari yong'in haqida bilishar ekan, ularni o'rmon yong'inlari sodir bo'lgan ishlov berilmagan erlar unchalik qiziqtirmagan.^[131][132] Yovvoyi yong'inlar insoniyat tarixidagi janglarda ishlatilgan dastlabki termal qurollar. Dan O'rta yosh, hisoblar yozilgan kasbni yoqish shuningdek, olovdan foydalanishni tartibga soluvchi urf-odatlar va qonunlar. Germaniyada muntazam yonish 1290 yilda hujjatlashtirilgan Odenvald va 1344 yilda Qora o'rmon.^[133] XIV asrda Sardiniya, yong'indan himoya qilish uchun o't o'chirish joylari ishlatilgan. Ispaniyada 1550-yillarda, qo'ychilik tomonidan ma'lum viloyatlarda tushkunlikka tushgan Filipp II ishlatilgan yong'inlarning zararli ta'siri tufayli transhumance.^[131][132] XVII asrdayoq tub amerikaliklar kuzatilgan olovdan foydalanish ko'p maqsadlar uchun, shu jumladan etishtirish, signal berish va urush. Shotlandiya botanigi Devid Duglas Odamlardan tamaki etishtirish uchun o'tdan foydalanishni, ovlarni ovlash uchun kichkina joylarga kiyiklarni jalb qilishni va asal va chigirtkalarni boqishni yaxshilashni ta'kidladilar. Markaziy Amerikaning Tinch okean qirg'og'idagi cho'kindi yotqiziqlaridan topilgan ko'mir shundan dalolat beradiki, undan 50 yil oldin Ispaniyaning Amerikani mustamlaka qilishi mustamlakadan keyin.^[134] Ikkinchi jahon urushidan keyingi davrda Boltiqbo'yi mintaqasi, ijtimoiy-iqtisodiy o'zgarishlar havo sifatining yanada qat'iy me'yorlarini keltirib chiqardi va yong'inlarni taqiqlash an'anaviy kuyish odatlarini yo'q qildi.^[133] 19-asr o'rtalarida kashfiyotchilar HMSBeagle kuzatilgan Avstraliya aborigenlari o'tni keyinchalik tozalash usulida tozalash, ovlash va o'simliklarning oziq-ovqat mahsulotlarini qayta tiklash uchun ishlatish o't o'chiradigan dehqonchilik.^[135] Olovdan bunday ehtiyotkorlik bilan foydalanish asrlar davomida muhofaza qilinadigan erlarda ishlatilgan Kakadu milliy bog'i bioxilma-xillikni rag'batlantirish.^[136]

O'rmon yong'inlari odatda harorat ko'tarilib, qurg'oqchilik paytida yuz berdi. Yong'in bilan bog'liq o'sish axlat oqimi yilda allyuvial muxlislar shimoli-sharqiy Yellowstone milliy bog'i milodiy 1050 yildan 1200 yilgacha bo'lgan davr bilan bog'lanib, bilan mos tushgan O'rta asrlarning iliq davri.^[137] Biroq, odamlarning ta'siri olov chastotasining oshishiga olib keldi. Dendroxronologik yong'in izlari va ko'mir qatlami ma'lumotlari Finlyandiya shuni ko'rsatadiki, ko'plab yong'inlar og'ir qurg'oqchilik sharoitida sodir bo'lgan bo'lsa-da, miloddan avvalgi 850 va milodiy 1660 yillarda yong'inlar sonining ko'payishi inson ta'siriga bog'liq bo'lishi mumkin.^[138] Amerikadan olingan ko'mir dalillari milodiy 1 dan 1750 yilgacha o'tgan yillarga nisbatan o'rmon yong'inlari umuman kamayganligini ko'rsatdi. Biroq, Shimoliy Amerika va Osiyodan olingan ko'mir ma'lumotlari bilan 1750-1870 yillarda yong'in chastotasining ko'payishi davri, bu odamlar sonining ko'payishi va erlarni tozalash amaliyoti kabi ta'sirlarga bog'liq edi. Ushbu davr 20-asrda qishloq xo'jaligining kengayishi, chorva mollari bilan boqishning ko'payishi va yong'inning oldini olish ishlari bilan bog'liq ravishda kuyishning umumiy pasayishi bilan davom etdi.^[139] Meta-tahlil shuni ko'rsatdiki, Kaliforniyada 1800 yilgacha har yili so'nggi o'n yilliklarga nisbatan 17 baravar ko'p er yoqilgan (yiliga 10200 ga ga nisbatan 1800000 gektar).^[140]

Da chop etilgan qog'ozga ko'ra Ilm-fan, tabiiy va inson tomonidan kelib chiqadigan yong'inlar soni 1998-2015 yillarda 24,3% ga kamaydi. Tadqiqotchilar buni o'tishdan tushuntirmoqdalar ko'chmanchilik yashash tarziga va kuchayishiga qishloq xo'jaligi bu erni tozalash uchun olovdan foydalanishning pasayishiga olib keladi.^[141][142]

Ba'zi mahalliy daraxt turlarining ko'payishi (ya'ni.) ignabargli daraxtlar ) boshqalarning foydasiga (ya'ni bargli daraxtlar), shuningdek, bu daraxtlar ekilgan bo'lsa, shuningdek, yong'in xavfini oshiradi monokulturalar^[143][144]

Biroz invaziv turlar, odamlar tomonidan ko'chirilgan (ya'ni, uchun sellyuloza va qog'oz sanoati ) ba'zi hollarda o'rmon yong'inlari intensivligini ham oshirgan. Kabi turlarni misol qilib keltirish mumkin Evkalipt Kaliforniyada^[145][146] va gamba maysasi Avstraliyada.

Oldini olish

Media-ni ijro etish

Shahar va tog 'yonbag'ridagi tabiiy yashash muhitini boshqarish va ularni yong'in xavfidan himoya qilish to'g'risida qisqacha video.

O'rmon yong'inlarining oldini olish yong'in xavfini kamaytirishga, shuningdek uning zo'ravonligi va tarqalishini kamaytirishga qaratilgan oldini olish usullarini nazarda tutadi.^[147] Oldini olish texnikasi havoning sifatini boshqarish, ekologik muvozanatni saqlash, resurslarni muhofaza qilish,^[89] va kelajakdagi yong'inlarga ta'sir qilish.^[148] Shimoliy Amerika yong'inga qarshi siyosati, tabiiy ravishda, yong'inlarning ekologik rolini saqlab qolish uchun yoqilishiga yo'l qo'yadi, chunki bu juda qimmatli hududlarga qochish xavfini kamaytiradi.^[149] Biroq, oldini olish siyosati odamlarning o'rmon yong'inlarida tutadigan rolini hisobga olishlari kerak, chunki, masalan, Evropadagi o'rmon yong'inlarining 95% inson ishtiroki bilan bog'liq.^[150] Odamlar tomonidan kelib chiqadigan yong'in manbalariga o't qo'yilishi, tasodifiy alangalanishi yoki Janubi-Sharqiy Osiyodagi qirg'ichli dehqonchilik kabi erni tozalash va qishloq xo'jaligida o'tning nazoratsiz ishlatilishi kiradi.^[151]

1985 Smokey Bear "O'rmon yong'inlarining oldini olish uchun faqat siz" degan nasihatining bir qismi yozilgan plakat.

1937 yilda AQSh prezidenti Franklin D. Ruzvelt o'rmon yong'inlarida odamlarning ehtiyotsizligi rolini ko'rsatib, mamlakat bo'ylab yong'inlarning oldini olish kampaniyasini boshladi. Keyinchalik dasturning plakatlari namoyish etildi Sem amaki, Disney filmidagi belgilar Bambi va rasmiy maskot AQSh o'rmon xizmati, Smokey Bear.^[152] Odamlar tomonidan kelib chiqadigan olovni kamaytirish istalmagan yong'inni kamaytirishning eng samarali vositasi bo'lishi mumkin. Yoqilg'i yoqilg'isini o'zgartirish odatda kelajakdagi yong'in xavfi va xatti-harakatiga ta'sir ko'rsatishda amalga oshiriladi.^[33] Butun dunyodagi o'rmon yong'inlarining oldini olish dasturlari kabi usullardan foydalanishi mumkin yovvoyi o'tlardan foydalanish va belgilangan yoki boshqariladigan kuyishlar.^[153][154] Wildland yong'inidan foydalanish har qanday tabiiy sabablarga ko'ra kuzatilib turilishi, ammo yonib ketishiga yo'l qo'yilishi mumkin. Boshqariladigan kuyishlar kam xavfli ob-havo sharoitida davlat idoralari tomonidan yoqiladigan yong'inlar.^[155]

A da belgilangan kuyish Pinus nigra turing Portugaliya

O'rmon yong'inlarining oldini olish, aniqlash, nazorat qilish va to'xtatish strategiyalari yillar davomida har xil bo'lib kelgan.^[156] Nazorat qilinmaydigan o'rmon yong'inlari xavfini kamaytirish uchun keng tarqalgan va arzon usullardan biri nazorat ostida yonish: mumkin bo'lgan o'rmon yong'inida mavjud bo'lgan yonuvchan material miqdorini minimallashtirish uchun ataylab kichikroq kuchli bo'lmagan yong'inlarni yoqish.^[157][158] O'simliklar vaqti-vaqti bilan yoqib yuborilishi mumkin bo'lgan o'simliklar va boshqa qoldiqlarning to'planishini cheklash va shu bilan birga turlarning xilma-xilligini saqlab qolish uchun yoqib yuborilishi mumkin.^[159][160] Yelloustoun dala stantsiyasining biologi Yan Van Vagtendonkning ta'kidlashicha, Wildfire o'zi "yong'in tarqalish tezligini, olov yoqilg'isi intensivligini, alanga uzunligini va maydon birligidagi issiqlikni kamaytirish uchun eng samarali davolash vositasidir".^[161] Boshqa odamlar, boshqariladigan kuyishlar va ba'zi bir yong'inlarning yoqilishiga yo'l qo'yish siyosati ko'plab o'rmonlar uchun eng arzon usul va ekologik jihatdan mos siyosat deb da'vo qilsalar-da, ular olov bilan iste'mol qilinadigan resurslarning iqtisodiy qiymatini, ayniqsa savdogarlarni hisobga olmaydilar. yog'och.^[84] Ba'zi tadkikotlar xulosasiga ko'ra, yoqilg'ilar ham o'tinni olib tashlash orqali olib tashlanishi mumkin, ammo bunday yupqalash muolajalari ekstremal ob-havo sharoitida yong'in zo'ravonligini kamaytirishda samarali bo'lmasligi mumkin.^[162]

Biroq, Amerika Qo'shma Shtatlari Qishloq xo'jaligi vazirligi, AQSh o'rmon xizmati Tinch okeanining shimoli-g'arbiy tadqiqot stantsiyasi va Montana universiteti o'rmon xo'jaligi maktabi va biznes va iqtisodiy tadqiqotlar byurosi tomonidan yong'in xavfini strategik baholash va turli xil xavf-xatarlarni kamaytirishning potentsial samaradorligi va xarajatlari, o'rmon yong'inlari xavfini kamaytirishning eng samarali qisqa va uzoq muddatli strategiyasi va uzoq vaqt davomida o'rmon yong'in xavfini kamaytirishning eng samarali usuli keng qamrovli yoqilg'i ekanligini aniq namoyish etadi. reduction strategy that involves mechanical removal of overstocked trees through commercial logging and non-commercial thinning with no restrictions on the size of trees that are removed, resulting in considerably better long-term results compared to a non-commercial "thin below" operation or a commercial logging operation with diameter restrictions. Starting with a forest with a "high risk" of fire and a pre-treatment crowning index of 21, the "thin from below" practice of removing only very small trees resulted in an immediate crowning index of 43, with 29% of the post-treatment area rated "low risk" immediately and only 20% of the treatment area remaining "low risk" after 30 years, at a cost (net economic loss) of $439 per acre treated. Again starting with a forest at "high risk" of fire and a crowning index of 21, the strategy involving non-commercial thinning and commercial logging with size-restrictions resulted in an crowning index of 43 immediately post-treatment with 67% of the area considered "low risk" and 56% of the area remaining low risk after 30 years, at a cost (net economic loss) of $368 per acre treated. On the other hand, starting with a forest at "high risk" of fire and the same crowning index of 21, a comprehensive fire hazard reduction treatment strategy, without restrictions on size of trees removed, resulted in an immediate crowning index of 61 post-treatment with 69% of the treated area rated "low risk" immediately and 52% of the treated area remaining "low risk" after 30 years, with positive revenue (a net economic gain gain) of $8 per acre.^[163][164]

Building codes in fire-prone areas typically require that structures be built of flame-resistant materials and a defensible space be maintained by clearing flammable materials within a prescribed distance from the structure.^[165][166] Communities in the Filippinlar also maintain fire lines 5 to 10 meters (16 to 33 ft) wide between the forest and their village, and patrol these lines during summer months or seasons of dry weather.^[167] Continued residential development in fire-prone areas and rebuilding structures destroyed by fires has been met with criticism.^[168] The ecological benefits of fire are often overridden by the economic and safety benefits of protecting structures and human life.^[169]

Aniqlash

Dry Mountain Fire Lookout in the Ochoco milliy o'rmoni, Oregon, taxminan 1930 yil

Fast and effective detection is a key factor in wildfire fighting.^[170] Early detection efforts were focused on early response, accurate results in both daytime and nighttime, and the ability to prioritize fire danger.^[171] Fire lookout towers were used in the United States in the early 20th century and fires were reported using telephones, tashuvchi kaptarlar va heliographs.^[172] Aerial and land photography using instant cameras were used in the 1950s until infrared scanning was developed for fire detection in the 1960s. However, information analysis and delivery was often delayed by limitations in communication technology. Early satellite-derived fire analyses were hand-drawn on maps at a remote site and sent via overnight mail to the fire manager. Davomida 1988 yilda Yelloustondagi yong'inlar, a data station was established in G'arbiy Yellouston, permitting the delivery of satellite-based fire information in approximately four hours.^[171]

Currently, public hotlines, fire lookouts in towers, and ground and aerial patrols can be used as a means of early detection of forest fires. However, accurate human observation may be limited by operator fatigue, time of day, time of year, and geographic location. Electronic systems have gained popularity in recent years as a possible resolution to human operator error. A government report on a recent trial of three automated camera fire detection systems in Australia did, however, conclude "...detection by the camera systems was slower and less reliable than by a trained human observer". These systems may be semi- or fully automated and employ systems based on the risk area and degree of human presence, as suggested by GIS data analyses. An integrated approach of multiple systems can be used to merge satellite data, aerial imagery, and personnel position via Global joylashishni aniqlash tizimi (GPS) into a collective whole for near-realtime use by wireless Incident Command Centers.^[173]

A small, high risk area that features thick vegetation, a strong human presence, or is close to a critical urban area can be monitored using a local sensorlar tarmog'i. Detection systems may include simsiz sensorli tarmoqlar that act as automated weather systems: detecting temperature, humidity, and smoke.^{[174][175][176][177]} These may be battery-powered, solar-powered, or tree-rechargeable: able to recharge their battery systems using the small electrical currents in plant material.^[178] Larger, medium-risk areas can be monitored by scanning towers that incorporate fixed cameras and sensors to detect smoke or additional factors such as the infrared signature of carbon dioxide produced by fires. Additional capabilities such as tungi ko'rish, brightness detection, and color change detection may also be incorporated into sensor arrays.^{[179][180][181]}

Wildfires across the Bolqon in late July 2007 (MODIS rasm)

Satellite and aerial monitoring through the use of planes, helicopter, or UAVs can provide a wider view and may be sufficient to monitor very large, low risk areas. These more sophisticated systems employ GPS and aircraft-mounted infrared or high-resolution visible cameras to identify and target wildfires.^[182][183] Satellite-mounted sensors such as Tasavvur qiling "s Parcha bo'ylab skanerlash bo'yicha radiometr va Evropaning masofadan turib yo'ldoshi 's Along-Track Scanning Radiometer can measure infrared radiation emitted by fires, identifying hot spots greater than 39 °C (102 °F).^[184][185] The Milliy Okean va atmosfera boshqarmasi "s Hazard Mapping System combines remote-sensing data from satellite sources such as Geostatsionar operatsion atrof-muhit sun'iy yo'ldoshi (GOES), O'rtacha aniqlikdagi tasvirni spektroradiometr (MODIS), and Advanced Very High Resolution Radiometer (AVHRR) for detection of fire and smoke plume locations.^[186][187] However, satellite detection is prone to offset errors, anywhere from 2 to 3 kilometers (1 to 2 mi) for MODIS and AVHRR data and up to 12 kilometers (7.5 mi) for GOES data.^[188] Satellites in geostationary orbits may become disabled, and satellites in polar orbits are often limited by their short window of observation time. Cloud cover and image resolution may also limit the effectiveness of satellite imagery.^[189]

In 2015 a new fire detection tool is in operation at the AQSh qishloq xo'jaligi vazirligi (USDA) O'rmon xizmati (USFS) which uses data from the Suomi National Polar-orbiting Partnership (NPP) satellite to detect smaller fires in more detail than previous space-based products. The high-resolution data is used with a computer model to predict how a fire will change direction based on weather and land conditions. The active fire detection product using data from Suomi NPP's Ko'rinadigan infraqizil tasvirlash radiometrlari to'plami (VIIRS) increases the resolution of fire observations to 1,230 feet (375 meters). Previous NASA satellite data products available since the early 2000s observed fires at 3,280 foot (1 kilometer) resolution. The data is one of the intelligence tools used by the USFS and Department of Interior agencies across the United States to guide resource allocation and strategic fire management decisions. The enhanced VIIRS fire product enables detection every 12 hours or less of much smaller fires and provides more detail and consistent tracking of fire lines during long-duration wildfires – capabilities critical for early warning systems and support of routine mapping of fire progression. Active fire locations are available to users within minutes from the satellite overpass through data processing facilities at the USFS Remote Sensing Applications Center, which uses technologies developed by the NASA Goddard Space Flight Center Direct Readout Laboratory in Greenbelt, Maryland. The model uses data on weather conditions and the land surrounding an active fire to predict 12–18 hours in advance whether a blaze will shift direction. The state of Colorado decided to incorporate the weather-fire model in its firefighting efforts beginning with the 2016 fire season.

In 2014, an international campaign was organized in South Africa's Kruger National Park to validate fire detection products including the new VIIRS active fire data. In advance of that campaign, the Meraka Institute of the Council for Scientific and Industrial Research in Pretoria, South Africa, an early adopter of the VIIRS 375m fire product, put it to use during several large wildfires in Kruger.

The demand for timely, high-quality fire information has increased in recent years. Wildfires in the United States burn an average of 7 million acres of land each year. For the last 10 years, the USFS and Department of Interior have spent a combined average of about $2–4 billion annually on wildfire suppression.

Bostirish

A Russian firefighter extinguishing a wildfire

Wildfire suppression depends on the technologies available in the area in which the wildfire occurs. In less developed nations the techniques used can be as simple as throwing sand or beating the fire with sticks or palm fronds.^[190] In more advanced nations, the suppression methods vary due to increased technological capacity. Kumush yodid can be used to encourage snow fall,^[191] esa fire retardants and water can be dropped onto fires by uchuvchisiz uchish vositalari, samolyotlar va vertolyotlar.^[192][193] Complete fire suppression is no longer an expectation, but the majority of wildfires are often extinguished before they grow out of control. While more than 99% of the 10,000 new wildfires each year are contained, escaped wildfires under extreme weather conditions are difficult to suppress without a change in the weather. Wildfires in Canada and the US burn an average of 54,500 square kilometers (13,000,000 acres) per year.^[194][195]

Above all, fighting wildfires can become deadly. A wildfire's burning front may also change direction unexpectedly and jump across fire breaks. Intense heat and smoke can lead to disorientation and loss of appreciation of the direction of the fire, which can make fires particularly dangerous. For example, during the 1949 Mann Gulch olovi yilda Montana, United States, thirteen tutun o'tish moslamalari died when they lost their communication links, became disoriented, and were overtaken by the fire.^[196] In the Australian 2009 yil fevral oyida Viktoriya shov-shuvlari, at least 173 people died and over 2,029 homes and 3,500 structures were lost when they became engulfed by wildfire.^[197]

Costs of wildfire suppression

In California, the U.S. Forest Service spends about $200 million per year to suppress 98% of wildfires and up to $1 billion to suppress the other 2% of fires that escape initial attack and become large.^[198] While costs vary wildly from year to year, depending on the severity of each fire season, in the United States, local, state, federal and tribal agencies collectively spend tens of billions of dollars annually to suppress wildfires.

Wildland firefighting safety

Wildfire fighters cutting down a tree using a chainsaw

Wildland firefighter working a brush fire in Xopkinton, Nyu-Xempshir

Wildland fire fighters face several life-threatening hazards including issiqlik stresi, charchoq, tutun va chang, as well as the risk of other injuries such as kuyish, kesishlar va qirg'ichlar, animal bites va hatto rabdomiyoliz.^[199][200] Between 2000–2016, more than 350 wildland firefighters died on-duty.^[201]

Especially in hot weather conditions, fires present the risk of heat stress, which can entail feeling heat, fatigue, weakness, vertigo, headache, or nausea. Heat stress can progress into heat strain, which entails physiological changes such as increased heart rate and core body temperature. This can lead to heat-related illnesses, such as heat rash, cramps, exhaustion or issiqlik urishi. Various factors can contribute to the risks posed by heat stress, including strenuous work, personal risk factors such as age and fitness, dehydration, sleep deprivation, and burdensome shaxsiy himoya vositalari. Rest, cool water, and occasional breaks are crucial to mitigating the effects of heat stress.^[199]

Smoke, ash, and debris can also pose serious respiratory hazards to wildland firefighters. The smoke and dust from wildfires can contain gases such as uglerod oksidi, oltingugurt dioksidi va formaldegid, shu qatorda; shu bilan birga zarrachalar kabi kul va kremniy. To reduce smoke exposure, wildfire fighting crews should, whenever possible, rotate firefighters through areas of heavy smoke, avoid downwind firefighting, use equipment rather than people in holding areas, and minimize mop-up. Camps and command posts should also be located upwind of wildfires. Protective clothing and equipment can also help minimize exposure to smoke and ash.^[199]

Firefighters are also at risk of cardiac events including strokes and heart attacks. Firefighters should maintain good physical fitness. Fitness programs, medical screening and examination programs which include stress tests can minimize the risks of firefighting cardiac problems.^[199] Other injury hazards wildland firefighters face include slips, trips, falls, burns, scrapes, and cuts from tools and equipment, being struck by trees, vehicles, or other objects, plant hazards such as thorns and poison ivy, snake and animal bites, vehicle crashes, electrocution from power lines or lightning storms, and unstable building structures.^[199]

Firefighter safety zone guidelines

The U.S. Forest Service publishes guidelines for the minimum distance a firefighter should be from a flame.^[202]

Fire retardants

Fire retardants are used to slow wildfires by inhibiting combustion. They are aqueous solutions of ammonium phosphates and ammonium sulfates, as well as thickening agents.^[203] The decision to apply retardant depends on the magnitude, location and intensity of the wildfire. In certain instances, fire retardant may also be applied as a precautionary fire defense measure.^[204]

Typical fire retardants contain the same agents as fertilizers. Fire retardants may also affect water quality through leaching, eutrophication, or misapplication. Fire retardant's effects on drinking water remain inconclusive.^[205] Dilution factors, including water body size, rainfall, and water flow rates lessen the concentration and potency of fire retardant.^[204] Wildfire debris (ash and sediment) clog rivers and reservoirs increasing the risk for floods and erosion that ultimately slow and/or damage water treatment systems.^[205][206] There is continued concern of fire retardant effects on land, water, wildlife habitats, and watershed quality, additional research is needed. However, on the positive side, fire retardant (specifically its nitrogen and phosphorus components) has been shown to have a fertilizing effect on nutrient-deprived soils and thus creates a temporary increase in vegetation.^[204]

The current USDA procedure maintains that the aerial application of fire retardant in the United States must clear waterways by a minimum of 300 feet in order to safeguard effects of retardant runoff. Aerial uses of fire retardants are required to avoid application near waterways and endangered species (plant and animal habitats). After any incident of fire retardant misapplication, the U.S. Forest Service requires reporting and assessment impacts be made in order to determine a mitigation, remediation, and/or restrictions on future retardant uses in that area.

Modellashtirish

Fire Propagation Model

Wildfire modeling is concerned with raqamli simulyatsiya of wildfires in order to comprehend and predict fire behavior.^[207][208] Wildfire modeling aims to aid wildfire suppression, increase the safety of firefighters and the public, and minimize damage. Foydalanish hisoblash fani, wildfire modeling involves the statistical analysis of past fire events to predict spotting risks and front behavior. Various wildfire propagation models have been proposed in the past, including simple ellipses and egg- and fan-shaped models. Early attempts to determine wildfire behavior assumed terrain and vegetation uniformity. However, the exact behavior of a wildfire's front is dependent on a variety of factors, including wind speed and slope steepness. Modern growth models utilize a combination of past ellipsoidal descriptions and Huygens' Principle to simulate fire growth as a continuously expanding polygon.^[209][210] Haddan tashqari qiymat nazariyasi may also be used to predict the size of large wildfires. However, large fires that exceed suppression capabilities are often regarded as statistical outliers in standard analyses, even though fire policies are more influenced by large wildfires than by small fires.^[211]

2003 Canberra firestorm

Human risk and exposure

2009 California Wildfires at NASA / JPL – Pasadena, California

Wildfire risk is the chance that a wildfire will start in or reach a particular area and the potential loss of human values if it does. Risk is dependent on variable factors such as human activities, weather patterns, availability of wildfire fuels, and the availability or lack of resources to suppress a fire.^[212] Wildfires have continually been a threat to human populations. However, human-induced geographical and climatic changes are exposing populations more frequently to wildfires and increasing wildfire risk. It is speculated that the increase in wildfires arises from a century of wildfire suppression coupled with the rapid expansion of human developments into fire-prone wildlands.^[213] Wildfires are naturally occurring events that aid in promoting forest health. Global warming and climate changes are causing an increase in temperatures and more droughts nationwide which contributes to an increase in wildfire risk.^[214][215]

Airborne hazards

The most noticeable adverse effect of wildfires is the destruction of property. However, the release of hazardous chemicals from the burning of wildland fuels also significantly impacts health in humans.^[216]

Wildfire smoke is composed primarily of carbon dioxide and water vapor. Other common smoke components present in lower concentrations are carbon monoxide, formaldehyde, acrolein, polyaromatic hydrocarbons, and benzene.^[217] Small particulates suspended in air which come in solid form or in liquid droplets are also present in smoke. 80 -90% of wildfire smoke, by mass, is within the fine particle size class of 2.5 micrometers in diameter or smaller.^[218]

Despite carbon dioxide's high concentration in smoke, it poses a low health risk due to its low toxicity. Rather, carbon monoxide and fine particulate matter, particularly 2.5 µm in diameter and smaller, have been identified as the major health threats.^[217] Other chemicals are considered to be significant hazards but are found in concentrations that are too low to cause detectable health effects.

The degree of wildfire smoke exposure to an individual is dependent on the length, severity, duration, and proximity of the fire. People are exposed directly to smoke via the respiratory tract through inhalation of air pollutants. Indirectly, communities are exposed to wildfire debris that can contaminate soil and water supplies.

The AQSh atrof-muhitni muhofaza qilish agentligi (EPA) developed the havo sifati ko'rsatkichi (AQI), a public resource that provides national air quality standard concentrations for common air pollutants. The public can use this index as a tool to determine their exposure to hazardous air pollutants based on visibility range.^[219]

Fire ecologist Leda Kobziar found that wildfire smoke distributes microbial life on a global level.^[220] She stated, "There are numerous allergens that we’ve found in the smoke. And so it may be that some people who are sensitive to smoke have that sensitivity, not only because of the particulate matter and the smoke but also because there are some biological organisms in it."^[221]

Post-fire risks

Charred shrubland in suburban Sidney (2019–20 avstraliyalik yong'inlar ).

After a wildfire, hazards remain. Residents returning to their homes may be at risk from falling fire-weakened trees. Humans and pets may also be harmed by falling into ash pits.

At-risk groups

Yong'in o'chiruvchilar

Firefighters are at the greatest risk for acute and chronic health effects resulting from wildfire smoke exposure. Due to firefighters' occupational duties, they are frequently exposed to xavfli kimyoviy moddalar at close proximity for longer periods of time. A case study on the exposure of wildfire smoke among wildland firefighters shows that firefighters are exposed to significant levels of carbon monoxide and respiratory irritants above OSHA -permissible exposure limits (PEL) and ACGIH threshold limit values (TLV). 5–10% are overexposed. The study obtained exposure concentrations for one wildland firefighter over a 10-hour shift spent holding down a fireline. The firefighter was exposed to a wide range of carbon monoxide and respiratory irritants (a combination of particulate matter 3.5 µm and smaller, acrolein, and formaldehyde) levels. Carbon monoxide levels reached up to 160ppm and the TLV irritant index value reached a high of 10. In contrast, the OSHA PEL for carbon monoxide is 30ppm and for the TLV respiratory irritant index, the calculated threshold limit value is 1; any value above 1 exceeds exposure limits.^[222]

Between 2001 and 2012, over 200 o'lim occurred among wildland firefighters. In addition to heat and chemical hazards, firefighters are also at risk for electrocution from power lines; injuries from equipment; slips, trips, and falls; injuries from vehicle rollovers; heat-related illness; insect bites and stings; stress; va rabdomiyoliz.^[223]

Aholi

Smoke from the 2020 yil Kaliforniyadagi o'rmon yong'inlari settles over San-Fransisko

Residents in communities surrounding wildfires are exposed to lower concentrations of chemicals, but they are at a greater risk for indirect exposure through water or soil contamination. Exposure to residents is greatly dependent on individual susceptibility. Vulnerable persons such as children (ages 0–4), the elderly (ages 65 and older), smokers, and pregnant women are at an increased risk due to their already compromised body systems, even when the exposures are present at low chemical concentrations and for relatively short exposure periods.^[217] They are also at risk for future wildfires and may move away to areas they consider less risky.^[224]

Wildfires affect large numbers of people in Western Canada and the United States. In California alone, more than 350,000 people live in towns and cities in "very high fire hazard severity zones".^[225]

Fetal exposure

Additionally, there is evidence of an increase in maternal stress, as documented by researchers M.H. O'Donnell and A.M. Behie, thus affecting birth outcomes. In Australia, studies show that male infants born with drastically higher average birth weights were born in mostly severely fire-affected areas. This is attributed to the fact that maternal signals directly affect fetal growth patterns.^[226][227]

Asthma is one of the most common chronic disease among children in the United States affecting estimated 6.2 million children.^[228] A recent area of research on asthma risk focuses specifically on the risk of air pollution during the gestational period. Several pathophysiology processes are involved are in this. In human's considerable airway development occurs during the 2nd and 3rd trimester and continue until 3 years of age.^[229] It is hypothesized that exposure to these toxins during this period could have consequential effects as the epithelium of the lungs during this time could have increased permeability to toxins. Exposure to air pollution during parental and pre-natal stage could induce epigenetic changes which are responsible for the development of asthma.^[230] Recent Meta-Analyses have found significant association between PM_2.5, YO'Q₂ and development of asthma during childhood despite heterogeneity among studies.^[231] Furthermore, maternal exposure to chronic stressor, which are most like to be present in distressed communities, which is also a relevant co relate of childhood asthma which may further help explain the early childhood exposure to air pollution, neighborhood poverty and childhood risk. Living in distressed neighborhood is not only linked to pollutant source location and exposure but can also be associated with degree of magnitude of chronic individual stress which can in turn alter the allostatic load of the maternal immune system leading to adverse outcomes in children, including increased susceptibility to air pollution and other hazards.^[232]

Sog'likka ta'siri

Yashil rangda ko'rsatilgan diafragma bilan diafragma nafas olish animatsiyasi

Wildfire smoke contains particulate matter that may have adverse effects upon the human respiratory system. Evidence of the health effects of wildfire smoke should be relayed to the public so that exposure may be limited. Evidence of health effects can also be used to influence policy to promote positive health outcomes.^[233]

Inhalation of smoke from a wildfire can be a health hazard.^[234] Wildfire smoke is composed of combustion products i.e. karbonat angidrid, uglerod oksidi, suv bug'lari, zarrachalar, organic chemicals, azot oksidlari and other compounds. The principal health concern is the inhalation of particulate matter and carbon monoxide.^[235]

Particulate matter (PM) is a type of air pollution made up of particles of dust and liquid droplets. They are characterized into three categories based on the diameter of the particle: coarse PM, fine PM, and ultrafine PM. Coarse particles are between 2.5 micrometers and 10 micrometers, fine particles measure 0.1 to 2.5 micrometers, and ultrafine particle are less than 0.1 micrometer. Each size can enter the body through inhalation, but the PM impact on the body varies by size. Coarse particles are filtered by the upper airways and these particles can accumulate and cause pulmonary inflammation. This can result in eye and sinus irritation as well as sore throat and coughing.^[236][237] Coarse PM is often composed of materials that are heavier and more toxic that lead to short-term effects with stronger impact.^[237]

Smaller particulate moves further into the respiratory system creating issues deep into the lungs and the bloodstream.^[236][237] In asthma patients, PM_2.5 causes inflammation but also increases oxidative stress in the epithelial cells. These particulates also cause apoptosis and autophagy in lung epithelial cells. Both processes cause the cells to be damaged and impacts the cell function. This damage impacts those with respiratory conditions such as asthma where the lung tissues and function are already compromised.^[237] The third PM type is ultra-fine PM (UFP). UFP can enter the bloodstream like PM_2.5 however studies show that it works into the blood much quicker. The inflammation and epithelial damage done by UFP has also shown to be much more severe.^[237] Bosh vazir_2.5 is of the largest concern in regards to wildfire.^[233] This is particularly hazardous to the very young, elderly and those with chronic conditions such as asthma, chronic obstructive pulmonary disease (COPD), cystic fibrosis and cardiovascular conditions. The illnesses most commonly with exposure to the fine particles from wildfire smoke are bronchitis, exacerbation of asthma or COPD, and pneumonia. Symptoms of these complications include wheezing and shortness of breath and cardiovascular symptoms include chest pain, rapid heart rate and fatigue.^[236]

Asthma exacerbation

Smoke from wildfires can cause health problems, especially for children and those who already have respiratory problems.^[238] Several epidemiological studies have demonstrated a close association between havoning ifloslanishi and respiratory allergic diseases such as bronchial Astma.^[233]

An observational study of smoke exposure related to the 2007 San Diego wildfires revealed an increase both in healthcare utilization and respiratory diagnoses, especially Astma among the group sampled.^[238] Projected climate scenarios of wildfire occurrences predict significant increases in respiratory conditions among young children.^[238] Particulate Matter (PM) triggers a series of biological processes including inflammatory immune response, oksidlovchi stress, which are associated with harmful changes in allergic respiratory diseases.^[239]

Although some studies demonstrated no significant acute changes in lung function among people with Astma related to PM from wildfires, a possible explanation for these counterintuitive findings is the increased use of quick-relief medications, such as inhalers, in response to elevated levels of smoke among those already diagnosed with Astma.^[240] In investigating the association of medication use for obstructive lung disease and wildfire exposure, researchers found increases both in the usage of inhalers and initiation of long-term control as in oral steroids.^[240] More specifically, some people with Astma reported higher use of quick-relief medications (inhalers).^[240] After two major wildfires in California, researchers found an increase in physician prescriptions for quick-relief medications in the years following the wildfires than compared to the year before each occurrence.^[240]

There is consistent evidence between wildfire smoke and the exacerbation of asthma.^[240]

Carbon monoxide danger

Carbon monoxide (CO) is a colorless, odorless gas that can be found at the highest concentration at close proximity to a smoldering fire. For this reason, carbon monoxide inhalation is a serious threat to the health of wildfire firefighters. CO in smoke can be inhaled into the lungs where it is absorbed into the bloodstream and reduces oxygen delivery to the body's vital organs. At high concentrations, it can cause headaches, weakness, dizziness, confusion, nausea, disorientation, visual impairment, coma, and even death. However, even at lower concentrations, such as those found at wildfires, individuals with cardiovascular disease may experience chest pain and cardiac arrhythmia.^[217] A recent study tracking the number and cause of wildfire firefighter deaths from 1990–2006 found that 21.9% of the deaths occurred from heart attacks.^[241]

Another important and somewhat less obvious health effect of wildfires is psychiatric diseases and disorders. Both adults and children from countries ranging from the United States and Canada to Greece and Australia who were directly and indirectly affected by wildfires were found by researchers to demonstrate several different mental conditions linked to their experience with the wildfires. Bunga quyidagilar kiradi travmadan keyingi stress buzilishi (TSSB), depressiya, anxiety, and fobiya.^{[242][243][244][245][246]}

In a new twist to wildfire health effects, former uranium mining sites were burned over in the summer of 2012 near North Fork, Idaho. This prompted concern from area residents and Idaho State Department of Environmental Quality officials over the potential spread of radiation in the resultant smoke, since those sites had never been completely cleaned up from radioactive remains.^[247]

Epidemiologiya

The western US has seen an increase in both the frequency and intensity of wildfires over the last several decades. This increase has been attributed to the arid climate of the western US and the effects of global warming. An estimated 46 million people were exposed to wildfire smoke from 2004 to 2009 in the Western United States. Evidence has demonstrated that wildfire smoke can increase levels of particulate matter in the atmosphere.^[233]

The EPA has defined acceptable concentrations of particulate matter in the air, through the National Ambient Air Quality Standards and monitoring of ambient air quality has been mandated.^[248] Due to these monitoring programs and the incidence of several large wildfires near populated areas, epidemiological studies have been conducted and demonstrate an association between human health effects and an increase in fine particulate matter due to wildfire smoke.

The EPA has defined acceptable concentrations of particulate matter in the air. The National Ambient Air Quality Standards are part of the Clean Air Act and provide mandated guidelines for pollutant levels and the monitoring of ambient air quality.^[248] In addition to these monitoring programs, the increased incidence of wildfires near populated areas has precipitated several epidemiological studies. Such studies have demonstrated an association between negative human health effects and an increase in fine particulate matter due to wildfire smoke. The size of the particulate matter is significant as smaller particulate matter (fine) is easily inhaled into the human respiratory tract. Often, small particulate matter can be inhaled into deep lung tissue causing respiratory distress, illness, or disease.^[233]

An increase in PM smoke emitted from the Hayman fire in Colorado in June 2002, was associated with an increase in respiratory symptoms in patients with COPD.^[249] Looking at the wildfires in Southern California in October 2003 in a similar manner, investigators have shown an increase in hospital admissions due to asthma symptoms while being exposed to peak concentrations of PM in smoke.^[250] Another epidemiological study found a 7.2% (95% confidence interval: 0.25%, 15%) increase in risk of respiratory related hospital admissions during smoke wave days with high wildfire-specific particulate matter 2.5 compared to matched non-smoke-wave days.^[233]

Children participating in the Children's Health Study were also found to have an increase in eye and respiratory symptoms, medication use and physician visits.^[251] Recently, it was demonstrated that mothers who were pregnant during the fires gave birth to babies with a slightly reduced average birth weight compared to those who were not exposed to wildfire during birth. Suggesting that pregnant women may also be at greater risk to adverse effects from wildfire.^[252] Worldwide it is estimated that 339,000 people die due to the effects of wildfire smoke each year.^[253]

While the size of particulate matter is an important consideration for health effects, the chemical composition of particulate matter (PM_2.5) from wildfire smoke should also be considered. Antecedent studies have demonstrated that the chemical composition of PM_2.5 from wildfire smoke can yield different estimates of human health outcomes as compared to other sources of smoke.^[233] health outcomes for people exposed to wildfire smoke may differ from those exposed to smoke from alternative sources such as solid fuels.

Madaniy jihatlar

Wildfires have a place in many cultures. "To spread like wildfire" is a common idiom in English, meaning something that "quickly affects or becomes known by more and more people".^[254] The Smokey Bear fire prevention campaign has yielded one of the most popular characters in the United States; for many years there was a living Smokey Bear mascot, and it has been commemorated on postage stamps.^[255]

Wildfire activity has been attributed as a major factor in the development of Qadimgi Yunoniston. In modern Greece, as in many other regions, it is the most common natural disaster and figures prominently in the social and economic lives of its people.^[256]

Ilmiy aloqa

Scientific communication is one of the main tools used to save lives and educate the public on wildfire safety and preparation. There are certain steps that institutions can take in order to communicate effectively with communities and organizations. Some of these include; fostering trust and credibility within communities by using community leaders as spokespeople for information, connecting with individuals by acknowledging concerns, needs, and challenges faced by communities, and utilizing information relevant to the specific targeted community. ^[257]

In regards to communicating information to the public regarding wildfire safety, some of the most effective ways to communicate with others about wildfires are community outreach conducted through presentations to homeowners and neighborhood associations, community events such as festivals and county fairs, and youth programs.^[257]

Another way to communicate effectively is to follow the "Four C's"^[257] which are Credentials, Connection, Context, and Catalyst. Credentials mean that one is using credible resources along with personal testimonials when presenting. Connection is the next step and means personal identification with the topic of wildfires as well as acknowledgement of what is already known regarding the specific situation. Context is relating information to how it fits into the lives of community members. And Catalyst is briefing community members on the steps they can follow to keep themselves and each other safe.^[257]

Shuningdek qarang

Adabiyotlar

Scholia bor mavzu uchun profil Yong'in.

Bibliografiya

Tashqi havolalar

• Diametri 1 mikrometrdan kam bo'lgan havodagi zarrachalarning, shu jumladan tutunni global xaritasi.

Ushbu maqola o'z ichiga oladijamoat mulki materiallari veb-saytlaridan yoki hujjatlaridan Milliy park xizmati.

Ushbu maqola o'z ichiga oladijamoat mulki materiallari veb-saytlaridan yoki hujjatlaridan Mehnatni muhofaza qilish milliy instituti.