• Potential recharge estimates of Arctic lakes to aid water management on the North Slope of Alaska

      Cormack, Chad Michael (2011-08)
      Water is a valuable asset to the petroleum industry on the North Slope of Alaska. Current water-permitting processes do not take into account watershed principles in the allocation of water resources. This has primarily been due to lack of information related to tundra lake watersheds and associated water use. This thesis evaluated several study lakes located within the eastern portion of the National Petroleum Reserve Alaska (NPRA) to demonstrate how watershed and meteorological parameters could be incorporated into water-use management practices. Watershed areas were delineated for the study lakes digitally with geographic information systems (GIS) and Rivertools software. Estimates for rainfall, snow-water equivalent, and evapotranspiration were combined to calculate potential recharge estimates for each individual study lake. A potential recharge tool was developed to help calculate potential recharge values. This tool can be a good first step for industry to begin to apply watershed principles into the water-permitting processes. For the study lakes analyzed, it was concluded that water withdrawal would not adversely affect the sustainability of the water bodies. With the current level of available data, recharge estimates are accurate enough to be used in permitting processes. It is recommended that geographic lake parameters (i.e., watershed and lake areas) and meteorological parameters (e.g., rain, snow, evapotranspiration) are further studied and included in future lake permits.
    • Remote sensing and GIS analysis of the spatial and morphological changes of thermokarst lakes: Kolyma lowlands, northeast Siberia

      Tillapaugh, Meghan L. (2011-05)
      Thermokarst 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.