Hasashen muhalli

Hasashen muhalli yana amfani da ilimin kimiyyar lissafi, muhalli da ilimin lissafi, don yin hasashen yadda yawan muhalli, al'ummomi, ko tsarin halittu zasu canza a nan gaba don mayar da martani ga abubuwan muhalli kamar Canjin yanayi. Manufar hanyar ita ce samar da manajojin albarkatun kasa da bayanai don tsammanin da amsawa ga yanayin yanayi na gajeren lokaci da na dogon lokaci.

Canjin yanayin yanayi ya gabatar da masu ilimin muhalli tare da ƙalubalen yin hasashen inda, lokacin da kuma irin girman canje-canje zasu iya faruwa don mu iya ragewa ko aƙalla shirya su. Hasashen muhalli yana amfani da ilimin da ke akwai game da hulɗar muhalli don yin hasashen yadda canje-canje a cikin abubuwan muhalli zasu iya haifar da canje-canje ga tsarin muhalli gaba ɗaya.

Ɗaya daga cikin cikakkun tushe a kan batun shine littafin Ecological Forecasting wanda Michael C. Dietze ya rubuta.

 Hanyoyi 
Masana ilimin muhalli sun sauya zuwa hanyoyin Bayesian tun daga shekarar 1990, lokacin da ci gaba a cikin ikon lissafi ya ba da damar amfani da ƙididdigar ƙididdiga masu mahimmanci kamar Hierarchical Bayes .  Irin wannan bincike yana amfani da Bayesian Network wanda ke ba da samfurin hoto na saiti na sigogi, kuma yana iya karɓar masu canji marasa ganuwa. Tsarin Bayesian shine tsarin yiwuwar da ke da sauƙi don bayanai masu girma, kuma yana bawa masu ilimin muhalli damar raba tushen rashin tabbas a cikin samfuran su.  

Hasashen na iya amfani da Bayes' Theorem kuma a sabunta shi akai-akai tare da sabbin abubuwan lura ta amfani da tsarin da ake kira Data Assimilation .  Bayanan Bayanai sun haɗu da abubuwan lura a kan ma'auni daban-daban na lokaci da na ƙasa tare da tsinkaya, dukansu sun haɗu don samar da ƙarin bayani fiye da kowane tushen bayanai ɗaya kadai. Wasu masu ilimin muhalli sun sami wannan tsarin yana da amfani ga samfuran muhalli kamar yadda sau da yawa suna dogaro da tushen bayanai masu yawa.

 Misalai 
Hasashen muhalli ya bambanta a cikin sararin samaniya da na lokaci, da kuma abin da ake hasashen (kasancewa, yalwa, bambancin, samarwa, da dai sauransu).

 Ana iya amfani da ƙirar yawan jama'a don samar da ɗimbin tsinkaya na ɗan gajeren lokaci ta amfani da ilimin ƙarfin yawan jama'a da yanayin muhalli na baya-bayan nan. Ana amfani da waɗannan samfuran musamman a cikin kamun kifi da hasashen cututtuka .
 Ana iya amfani da samfuran rarraba  nau'ikan annabta (kasuwa ko yawa) akan ma'aunin ma'auni na lokacin muhalli ta amfani da bayanai game da abubuwan da suka gabata da kuma hasashen yanayin muhalli a cikin shimfidar wuri.
 SDMs masu daidaitawa, wanda kuma aka sani da samfuran ambulaf ɗin yanayi, sun dogara da alaƙar ƙididdiga tsakanin rarraba nau'ikan nau'ikan da ke akwai (iyakoki) da masu canjin muhalli don fayyace kewayon (ambulaf) na yanayin muhalli a cikinsa wanda nau'in zai iya wanzuwa.   Sabbin iyakokin kewayon sa'an nan za a iya yin hasashen ta amfani da matakan abubuwan muhalli na gaba kamar zazzabi, ruwan sama, da salinity daga hasashen yanayin yanayi. Waɗannan hanyoyin suna da kyau don bincika manyan nau'ikan nau'ikan, amma wataƙila ba kyakkyawar hanyar da ke haifar da tasirin sakamako ba.
 Mechanistic SDMs suna amfani da bayanai game da juriya da ƙuntatawa na nau'in halitta, da kuma ƙirar yanayin zafin jiki na kwayoyin halitta da sauran kaddarorin halittu, don ayyana kewayon yanayin muhalli wanda nau'in zai iya wanzuwa a ciki. An tsara waɗannan haƙƙoƙin zuwa kan halin yanzu da kuma hasashen yanayin muhalli a cikin shimfidar wuri don fayyace jeri na yanzu da kuma kintace ga nau'in.   Ya bambanta da hanyoyin "ambulaf na yanayi" hanyoyin, SDMs na injiniyoyi suna tsara ainihin alkuki kai tsaye, sabili da haka sun fi daidai.  Koyaya, tsarin yana buƙatar ƙarin bayani kuma yawanci yana ɗaukar lokaci. 
 Ana iya amfani da wasu nau'ikan samfura don hasashen (ko watsar) bambancin halittu akan ma'aunin lokacin juyin halitta. Samfuran Palaeobiology yana amfani da burbushin halittu da shaidar halittar halittu a baya don aiwatar da yanayin bambancin halittu a nan gaba. Za a iya gina filaye masu sauƙi sannan a daidaita su bisa la'akari da bambancin ingancin rikodin burbushin halittu. 

 Manazarta