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dc.contributor.authorTillapaugh, Meghan L.
dc.date.accessioned2020-10-22T16:51:00Z
dc.date.available2020-10-22T16:51:00Z
dc.date.issued2011-05
dc.identifier.urihttp://hdl.handle.net/11122/11376
dc.descriptionThesis (M.S.) University of Alaska Fairbanks, 2011en_US
dc.description.abstractThermokarst lakes develop when changes in the permafrost thermal regime cause degradation leading to surface subsidence and ponding. The degree of thermokarst development depends upon permafrost characteristics, topography, and geology. Changing thermokarst lake dynamics affect arctic ecosystems, hydrological patterns, albedo, and the carbon cycle through the mobilization of organic matter in the permafrost. This study used remote sensing and GIS techniques to relate lake dynamics in the Kolyma Lowlands, Siberia, to geology, elevation, geomorphological features, hydrology, and air temperature. Highest limnicity and largest lake sizes were found in regions with low elevation, limited alluvial processes, high ground-ice content, and lithologies with small particle sizes. New lake development and erosion occurred as well. One subregion studied showed lake area increases (Cherskii: +7.6%) while another showed a decrease (Duvanny Yar: -5.2%). Differences are attributed to variations in elevation and fluvial influences. A major cause of drainage was river tapping of lakes. Lake coalescence, flooding during river water level high stands, and lakeshore erosion were the main causes of lake expansion. The Kolyma Lowland soils have high ice and organic matter contents as well making the monitoring of thermokarst lake dynamics important as large amounts of freshwater and carbon could potentially be released.en_US
dc.description.tableofcontents1. Introducton -- 1.1. Permafrost and climate change -- 1.2. Thermokarst lakes -- 1.3. Changes during the Pleistocene-Holocene transition -- 1.4. Previous Siberian lake change studies -- 1.5. Goal of this research -- 2. Study region -- 3. Methods -- 3.1. Medium-resolution landsat images -- 3.2. High-resolution images -- 3.3. Non-image data sources -- 3.4. GIS analysis -- 3.4.1. Geo-referencing and image mosaics -- 3.4.2. Digitizing of the lakes -- 3.4.3. Remaining data processing -- 3.5. Regions of lake analysis -- 3.5.1. High-resolution study regions -- 3.5.2. Medium-resolution regional study -- 3.5.3. Lake erosion rates within Yedoma deposits -- 3.5.4. Calculating albedo change -- 4. Results -- 4.1. High-resolution local studies -- 4.1.1. Lake area in the Duvanny Yar region: lakes>0.5 ha -- 4.1.1.1. Lakes showing area loss greater than 20% -- 4.1.1.2. DEM and permafrost analysis -- 4.1.1.3. Small-lake dynamics -- 4.1.2. Lake area in the Cherskii region: lakes>0.5 ha -- Lakes showing area loss greater than 20% -- 4.1.2.2. DEM and permafrost analysis -- 4.1.2.3. Small-lake dynamics -- 4.2. Lakeshore erosion rates in Yedoma deposits -- 4.3. Albedo -- 4.4. Regional study with medium-resolution imagery -- 4.4.1. Lake distribution in 2007 -- 4.4.2. Accuracy of TM 2006/2007 lake file -- 4.4.3. Lakes showing substantial area loss -- 4.4.4. Geological analysis of lakes showing substantial lake area loss -- 4.4.5. Elevation analysis of lakes showing substantial lake area loss -- 4.4.6. Multi-temporal assessment of lake area loss -- 4.5. Climate analysis -- 5. Discussion -- 5.1. Effects of surface geology and geomorphology on lake distribution -- 5.2. Effects of surface geology and geomorphology on lake dynamics -- 5.3. Effects of permafrost on lake distribution and lake dynamics -- 5.4. Causes of lake area loss -- 5.5. Comparison with previous lake change studies -- 5.5.1. Comparison with previous studies on Siberian lakes -- 5.5.2. Comparison with previous studies completed within Alaska -- 5.5.2.1. Alaska permafrost conditions -- 5.5.2.2. Comparison with previous studies on Alaskan lakes -- 5.5.3. Comparison to other lake change studies -- 5.6. The larger scale problem and how these results contribute -- 5.7. Future trends -- 5.8. Usability of remote sensing and GIS to analyze thermokarst lakes -- 6. Conclusion -- 6.1. Overall changes to thermokarst lakes in the Kolyma lowlands -- 6.2. Outlook -- References.en_US
dc.language.isoen_USen_US
dc.subjectthermokarsten_US
dc.subjectresearchen_US
dc.subjectRussiaen_US
dc.subjectSiberiaen_US
dc.subjectpermafrosten_US
dc.subjectlakesen_US
dc.titleRemote sensing and GIS analysis of the spatial and morphological changes of thermokarst lakes: Kolyma lowlands, northeast Siberiaen_US
dc.typeThesisen_US
dc.type.degreemsen_US
dc.identifier.departmentDepartment of Geology and Geophysicsen_US
refterms.dateFOA2020-10-22T16:51:01Z


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