On 13 October at 15.00 Iuliia Burdun will defend her doctoral thesis "Improving groundwater table monitoring for Northern Hemisphere peatlands using optical and thermal satellite data“ for obtaining the degree of Doctor of Philosophy (Physical Geography).
Research Fellow Valentina Sagris (UT Institute of Ecology and Earth Sciences);
Professor Ülo Mander (UT Institute of Ecology and Earth Sciences).
Professor Margaret Kalacska (McGill University, Canada).
Peatlands are a type of wetlands, which have accumulated huge quantities of carbon as a plant matter. The accumulation of this carbon occurred in water-logged conditions and took thousands of years. Global climate change can lead to the drying of peatlands and, thus, the release of accumulated carbon in the form of greenhouse gas – carbon dioxide (CO2). Releasing CO2 into the atmosphere will amplify global climate change. Therefore, knowledge of water table depth in peatlands is essential for predicting future Earth climate. In this thesis, we present results of our four articles integrated together and they share one general aim – to improve the estimation of water table depth in Northern Hemisphere peatlands using remotely sensed information in thermal and optical spectra. We evaluated the usefulness of this information to detect the temporal and spatial changes in water table depth based on in-situ data collected in peatlands. Particularly, we used signals sensitive to moisture and green vegetation, and utilized them in several indices that indicate soil moisture conditions. In this thesis, we have determined, for the first time, that used in our study moisture index based on optical data has a strong temporal relationship with in-situ measured water table depth in peatlands. Moreover, we discussed the impact of vegetation cover on that relationship and suggested a method for selecting the most informative pixels of moisture index. In conclusion, we suggest the future perspectives of using optical-based moisture index together with challenges it might have.