Raws li California huab cua muaj kev kub ntxhov, cov cuab yeej uas tuaj yeem pab cov neeg ua liaj ua teb thiab cov neeg ua liaj ua teb ua kom cov dej ntau tshaj plaws uas lawv tau txais tau raug ua kom tiav.
Kev siv zog tshiab tshaj plaws los ntsuas qhov kev siv dej no tau tshaj tawm lub lim tiam dhau los los ntawm tsoomfwv-tswj koom ua ke uas muaj peb lub koomhaum tseemfwv qibsiab - National Aeronautics thiab Space Administration; US Department of Agriculture; thiab US Geological Survey - thiab ntau lub tsev kawm ntawv qib siab thiab cov chaw ntiav. OpenET, uas yog lub hom phiaj los taug qab kev siv dej thoob plaws 17 lub xeev sab hnub poob, tau mus nyob rau lub Kaum Hli 21 thiab muaj nyob ntawm www.openetdata.org
ET yog hais txog evapotranspiration, cov txheej txheem uas cov dej evaporates los ntawm thaj av thiab transpires los ntawm cov nroj tsuag.
Robyn Grimm, tus thawj coj ntawm kev nyab xeeb-resilient dej systems ntawm Environmental Defense Fund, piv txwv li kev tswj dej tsis muaj cov ntaub ntawv evapotranspiration los tswj cov peev nyiaj hauv tsev yam tsis paub tias yuav siv nyiaj ntau npaum li cas.
"Nws yog qhov thib ob loj tshaj plaws ntawm lub voj voog dej thiab tuaj yeem xav tias yog qhov tsis sib xws ntawm nag lossis daus," Grimm hais ntawm lub rooj sib tham xov xwm virtual tshaj tawm lub lim tiam dhau los. "Nws yog dej uas tawm hauv av thiab rov qab mus rau qhov chaw, thiab yog li ntawd, nws yog ib qho kev ntsuas ntawm cov dej uas tsis tuaj yeem siv rau hauv ib cheeb tsam ib zaug ib zaug nws tau siv rau toj roob hauv pes."
Qhov kev zov me nyuam pib nrog kev soj ntsuam satellite los ntawm Landsat, lub luag haujlwm sib koom ua ke ntawm NASA thiab Geological Survey. Qhov kev zov me nyuam muaj peb lub satellites nyob rau hauv orbit, qhov tshiab tshaj plaws uas tau tshaj tawm thaum lub Cuaj Hli. Cov ntaub ntawv los ntawm lwm lub NASA thiab European Space Agency satellites kuj tau siv.
Forrest Melton, tus kws tshawb fawb tshawb fawb ntawm NASA's Western Water Applications Office, tau hais hauv lub rooj sib tham xov xwm hais tias evapotranspiration siv lub zog thiab ua kom cov dej txias ntawm qhov chaw uas cov dej evaporating.
Melton tau hais tias "Qhov kev ua kom txias no pom tau rau Landsat lub thermal infrared sensor, uas kuaj pom tus nqi siab dua ntawm ET raws li qhov ntsuas kub ntawm thaj av txias dua," Melton tau hais. "Qhov txias txias, dhau los, txhais tau hais tias cov dej siv ntau dua lossis hloov pauv los ntawm cov nroj tsuag, thiab tseem evaporated los ntawm thaj av."
Cov nroj tsuag yuav cuam tshuam qhov sib txawv ntawm infrared thiab ze-infrared lub teeb nyob ntawm seb qhov kev noj qab haus huv ntawm cov nroj tsuag, Melton sau tseg.
"Qhov no tso cai rau peb suav ET rau ze li txhua qhov kev ua liaj ua teb nyob rau sab hnub poob, thiab tseem ntsuas qhov cuam tshuam ntawm kev kub ntxhov (thiab) hluav taws kub hnyiab thoob plaws toj roob hauv pes nrog cov ntsiab lus loj heev," Melton tau hais.
Kev sib txuas cov ntaub ntawv satellite nrog cov ntaub ntawv huab cua tso cai rau cov kws tshawb fawb los suav cov evapotranspiration tus nqi rau txhua pixel ntawm ib daim duab satellite, Melton tau hais tias, ntxiv tias txhua pixel ntsuas 30 los ntawm 30 meters, lossis txog ib feem peb ntawm ib daim av.
Tseem muaj kev siv dag zog hauv kev lag luam hauv cheeb tsam no thiab. Joel Kimmelshue tau tsim LandIQ hauv 2007 siv qee qhov kev siv thev naus laus zis los sawv cev ntawm nws cov neeg siv khoom.
Kimmelshue, uas tuaj ntawm Butte County tsev neeg ua liaj ua teb hais tias "Peb dai peb lub kaus mom kom muaj peev xwm sib txuas lus ncaj qha nrog tus neeg cog qoob loo thiab nkag siab tias tus neeg cog qoob loo xav li cas, vim tias kuv nyob ntawm ib puag ncig ntawd," Nws cov thev naus laus zis xyaum ua kom muaj kev daws teeb meem me dua li OpenET 10 meters los ntawm 10 meters, lossis 0.02 acre - thiab cov ntaub ntawv tsuas yog muaj rau cov neeg siv khoom. OpenET cov ntaub ntawv, los ntawm qhov sib txawv, yuav muaj rau pej xeem hauv kev txwv.
Ntxiv nrog rau kev cog qoob loo-mapping ua haujlwm rau Lub Xeev Lub Tsev Haujlwm Saib Xyuas Dej, LandIQ tab tom ua haujlwm evapotranspiration-cov ntaub ntawv sau rau ntau lub nroog cov dej thiab cov chaw ua haujlwm hauv av-txhawb nqa dej hauv qab kawg ntawm San Joaquin Valley.
"Lawv siv cov ntaub ntawv rau cov neeg cog qoob loo tam sim no ntawm cov dej uas lawv haus - dej ntau npaum li cas cov qoob loo hloov pauv piv rau cov qauv sau nqi ntau npaum li cas koj tau thov? Koj nqus dej ntau npaum li cas?" Kimmelshue hais.
"Tsis yog txhua txhua tee dej uas siv rau saum npoo av yog siv los ntawm cov qoob loo," nws hais ntxiv. "Koj xav kom nce mus txog 90% kev ua haujlwm lossis qhov ntawd yog tias koj tuaj yeem ua tau, tab sis cov dej seem rov qab mus rau hauv av."
Qhov kev ua tau zoo ntawm 90%, Kimmelshue piav qhia, txhais tau hais tias feem pua ntawm cov dej tau raug coj los ntawm cov nroj tsuag lossis tsob ntoo.
Nws hais tias "Qhov kev ua tau zoo tuaj yeem qis li 50%, nyob ntawm seb koj tswj dej li cas," nws hais. “Yog tias koj tsuas yog qhib koj lub twj tso kua mis thiab siv dej rau peb hnub ncaj, koj yuav siv dej ntau dua li cov qoob loo siv tau. Yog tias koj qhib koj lub twj tso kua mis thiab siv dej los teb rau qhov kev thov ntawm cov qoob loo, uas yog qhov peb cov ntaub ntawv muab, ces koj tuaj yeem tswj koj lub twj tso kua mis kom zoo dua. "
Kimmelshue tsis yog siv lub satellites lo lus rau nws - nws thiab nws cov neeg ua haujlwm siv sijhawm ntau ntawm txoj kev.
Kimmelshue tau hais tias "Peb lub lag luam me yog nyob rau hauv qhov hnyav qhov tseeb," Kimmelshue tau hais. "Peb muaj ib lub network txog li 80, mus txog 90 chaw nres tsheb tam sim no, huab cua ib puag ncig chaw nres tsheb hauv av uas ntsuas tej yam xws li cua ceev thiab kub thiab av noo thiab cov hluav taws xob hluav taws xob, thiab lwm yam, los xam qhov tseeb ET. Peb siv qhov ntawd los ua pawg calibration ntawm cov ntaub ntawv los qhia cov qauv. "
Nws txoj haujlwm cog qoob loo tuaj yeem ua ke zoo ib yam, nws tau sau tseg.
Kimmelshue tau hais tias "Peb muab cov phiaj xwm cog qoob loo rau hauv peb qhov kev tshuaj ntsuam," Kimmelshue tau hais. "Peb tuaj yeem saib ET ntawm almonds, ET ntawm walnuts, ET ntawm alfalfa."
Cov ntaub ntawv ntawd, nws hais tias, yuav tsum pab cov neeg ua liaj ua teb thiab cov neeg ua liaj ua teb cuam tshuam nrog kev nyob hauv lub tshuab tsom.
Kimmelshue tau hais tias "Muaj kev tshuaj xyuas ntau heev rau cov neeg cog qoob loo tam sim no txog kev ua tau zoo dua, ua tau zoo dua, ua tau zoo dua - twj tso kua mis tsawg, twj tso kua mis tsawg, twj tso kua mis tsawg," Kimmelshue tau hais. "Vim tias (Sustainable Groundwater Management Act), tej zaum yuav muaj cov av tseem ceeb nyob rau sab qab teb (San Joaquin) Valley thiab tej zaum lwm thaj chaw ntawm lub xeev. Cov neeg cog qoob loo yuav rub cov khoom siv dej kom deb li deb tau. Lawv tau txais kev txhawb siab tiag tiag kom tsis txhob siv ntau dhau ntawm lub sijhawm no. "
- Kevin Hecteman, California Farm Bureau Federation