Kaugseire kasutamise võimekusest klorofüll a kontsentratsioonide hindamisel erinevates Eesti järvedes
Laen...
Kuupäev
2016
Kättesaadavus
Autorid
Ajakirja pealkiri
Ajakirja ISSN
Köite pealkiri
Kirjastaja
Abstrakt
Kaugseirega on Eestis eelnevalt uuritud vaid Peipsit ja Võrtsjärve. Ülejäänud järvi ei ole
varem kaugseire abil uuritud, kuna siseveekogude seireks pole varasemate satelliitide
sensorite spektraalne ja ruumiline lahutus olnud piisav. 2013. aastal alustas missiooni
Landsat 8, mille pardal oleva sensori OLI lahutusvõime on 15 x 30 meetrit. Töö
eesmärgiks on tuvastada, kas kaugseire abil on võimalik Eesti erinevates järvedes
veekvaliteeti hinnata. 2014. ja 2015. aastal koguti pilvevabadel satelliidi ülelennu
päevadel veeproovid ning laboris mõõdeti klorofüll a, koguheljum ja värvunud
lahustunud orgaaniline aine. 2013. aasta Peipsi kontaktmõõtmiste tulemused saadi Tuuli
Soometsa käest. Töös kasutati Landsat 8 OLI sensori L2 andmeid, mis töödeldi
vabatarkvara programmis SeaDAS. Antud programmi abil leiti klorofüll a
kontsentratsioonid, mida võrreldi kontaktmõõtmiste käigus saadud andmetega. Lisaks
Peipsile ja Võrtsjärvele uuriti ka Kokora Mustjärve, Verevi järve, Harku järve ja Äntu
Sinijärve. Saadud OLI klorofüll a kontsentratsioonid sobisid in situ andmetega, olgugi, et
kahe aasta jooksul oli vaid üksikuid sobilikke mõõtmispäevi. Harku järve ja Äntu
Sinijärve kohta tulemused puuduvad, kuna satelliit neid ei tuvastanud.
Tulemused näitavad, et kaugseire andmed sobivad hästi tavamonitooringut täiendama,
andes võimaluse kontaktmõõtmiste käigus märkamata jäänud vetikaõitsenguid tuvastada.
Lake Võrtsjärv and Lake Peipus, the two biggest lakes in Estonia, are the only Estonian lakes that have been studied using remote sensing because the spectral and spatial resolution of previous satellite sensors has been insufficient for examining smaller lakes. In 2013 Landsat 8 started its mission with the Operational Land Imager (OLI) sensor on board, the spatial resolution of which is 15 x 30 meters. The goal of this thesis is to find out whether it is possible to determine the quality of water in different Estonian lakes using remote sensing. In 2014 and 2015 water samples were collected on cloudless satellite flyover days and Chlorophyll a, TSS and CDOM was measured in the laboratory. The in situ results for Lake Peipus in the year 2013 were obtained from Tuuli Soomets. In the research paper the raw data from the Landsat 8 sensor was processed into L2 data in SeaDAS freeware software. This software was used to determine the concentration of chlorophyll a which was then compared to the corresponding results obtained in situ. In addition to Lake Peipus and Lake Võrtsjärv Kokora Mustjärv, Lake Verevi, Lake Harku and Äntu Sinijärv were also tested. The obtained OLI concentration of chlorophyll a matched with the data obtained in situ, despite there having been only a few suitable test days during the 2 years. There is no data on Lake Harku and Äntu Sinijärv as they were not identified by the satellite. The results indicate that the data obtained by remote sensing can successfully be used to supplement conventional monitoring as it provides the opportunity to identify algal bloom that may have gone unnoticed during in situ tests.
Lake Võrtsjärv and Lake Peipus, the two biggest lakes in Estonia, are the only Estonian lakes that have been studied using remote sensing because the spectral and spatial resolution of previous satellite sensors has been insufficient for examining smaller lakes. In 2013 Landsat 8 started its mission with the Operational Land Imager (OLI) sensor on board, the spatial resolution of which is 15 x 30 meters. The goal of this thesis is to find out whether it is possible to determine the quality of water in different Estonian lakes using remote sensing. In 2014 and 2015 water samples were collected on cloudless satellite flyover days and Chlorophyll a, TSS and CDOM was measured in the laboratory. The in situ results for Lake Peipus in the year 2013 were obtained from Tuuli Soomets. In the research paper the raw data from the Landsat 8 sensor was processed into L2 data in SeaDAS freeware software. This software was used to determine the concentration of chlorophyll a which was then compared to the corresponding results obtained in situ. In addition to Lake Peipus and Lake Võrtsjärv Kokora Mustjärv, Lake Verevi, Lake Harku and Äntu Sinijärv were also tested. The obtained OLI concentration of chlorophyll a matched with the data obtained in situ, despite there having been only a few suitable test days during the 2 years. There is no data on Lake Harku and Äntu Sinijärv as they were not identified by the satellite. The results indicate that the data obtained by remote sensing can successfully be used to supplement conventional monitoring as it provides the opportunity to identify algal bloom that may have gone unnoticed during in situ tests.
Kirjeldus
Märksõnad
kaugseire, klorofüll, järved, Eesti, magistritööd