| Summary: | Dissertation (Ph.D.) University of Alaska Fairbanks, 2014 In this dissertation, interdisciplinary research methods were used to examine how changes in hydrology associated with climate affect Alaskans. Partnerships were established with residents of Fairbanks and Tanana to develop scientific investigations relevant to rural Alaskans. In chapter 2, local knowledge was incorporated into scientific models to identify a socialecological threshold used to model potential driftwood harvest from the Yukon River. Anecdotal evidence and subsistence calendar records were combined with scientific data to model the harvest rates of driftwood. Modeling results estimate that between 1980 and 2010 hydrologic factors alone were responsible for a 29% decrease in the annual wood harvest, which approximately balanced a 23% reduction in wood demand due to a decline in number of households. The community's installation of wood-fired boilers in 2007 created a threshold increase (76%) in wood demand that is not met by driftwood harvest. Modeling of climatic scenarios illustrates that increased hydrologic variability decreases driftwood harvest and increases the financial or temporal costs for subsistence users. In chapter 3, increased groundwater flow related to permafrost degradation was hypothesized to be affect river ice thickness in sloughs of the Tanana River. A physically-based, numerical model was developed to examine the importance of permafrost degradation in explaining unfrozen river conditions in the winter. Results indicated that ice melt is amplified by increasing groundwater upwelling rates, groundwater temperatures, and snowfall. Modeling results also suggest that permafrost degradation could be a valid explanation of the phenomenon, but does not address the potential drivers (e.g. warming climate, forest fire, etc.) of the permafrost warming. In chapter 4, remote sensing techniques were hypothesized to be useful for mapping dangerous ice conditions on the Tanana River in interior Alaska. Unsupervised classification ...
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