Document Type

Thesis

Date of Degree Completion

Summer 2018

Degree Name

Master of Science (MS)

Department

Resource Management

Committee Chair

Karl Lillquist

Second Committee Member

Lisa Ely

Third Committee Member

Patrick Lubinski

Abstract

Along the Columbia River, hundreds of miles of transportation infrastructure and over sixty hydroelectric dams have been constructed. This altered a rich cultural landscape with evidence of 10,000 years of continuous occupation. Researchers have attempted to understand the impacts of anthropogenic factors on the Columbia River, focusing on the riverine environment. However, the effect of transportation and hydroelectricity developments to eolian landforms on the floodplains and adjoining slopes have not been studied. Focusing on 2,800 acres near Celilo Falls, this study 1) establishes a baseline condition of eolian landforms from 1805 to 1900; 2) conducts an air photo increment analysis from 1930 to 2015; and 3) compares the role of hydroelectricity and transportation with that of agriculture, built environment, temperature, and precipitation in the observed landform responses. Baseline data suggests from 1805 to 1900 large pointbars were sediment sources for barchan dunes, lee dunes, linear dunes, and sandsheets. Airphoto increment analysis indicates from 1930 to 1956, an overall increase in total eolian landform area occurred and reversed after the construction of The Dalles Dam in 1957. The dam eliminated the primary sediment source for dunes, suggesting hydroelectricity was the primary factor in overall eolian landform decline. Transportation development, although an influential factor in the observed distribution of eolian landform area, was not the primary factor. Other factors showed important information related to eolian processes. The built environment was linked to growth of linear dunes with a ρ of 0.8424, which suggests easterly winds are important to their formation. Precipitation was linked to eolian deposition as lee dunes with a ρ of 0.8061, suggesting it activated sediments for eolian transport. An alternating trend between a fluvial- and eolian-dominant environment may exist between anchor dunes, sandsheets, and lee dunes. Further research is suggested to quantify the role of hydroelectricity and transportation in shaping eolian landforms and transportation.

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