Tag: Patricia McDowell

Using Remote Sensing Techniques to Assess Geomorphological Response to Engineered Log Jams Along the Middle Fork of the John Day River, Oregon

Presenter: Corey Guerrant

Mentor: Patricia McDowell

Oral Presentation

Major: Environmental Science

In the last 5-10 years, there have been intensive river restoration efforts along the Middle Fork of the John Day River—including the placement of engineered log jams—to increase sinuosity and help improve anadromous fish habitat. To understand how these log jams have affected river morphology, I have used aerial photography within a Geographic Information System to quantify river planform change over time in stream reaches with and without placed log jams. Specifically, I have looked at how the centerline of the river has changed between 2006 and 2011, before and after many of the log jams were installed. Preliminary results indicate that there have been areas of significant lateral movement, but it is still yet to be determined whether or not they are associated with the engineered log jams. To ground-truth my results, I traveled out to my study sites and looked for physical evidence of lateral movement in the specific areas indicated by my model. Upon the completion of my research, I will be able to propose important management implications on whether or not the engineered log jams have begun to create the desired geomorphological responses.

Estuary Coastline Change over a century in the Coos Bay, Oregon

Presenter(s): Kira Bartlett − Earth Science, Geography

Faculty Mentor(s): David Sutherland, Patricia McDowell

Oral Session 4CS

Research Area: Natural/Physical Science

Coos Bay Estuary is the largest bay between San Francisco and Puget Sound. The estuary serves an important role in the region’s economic prosperity through transportation and agriculture. The purpose was to study the Coos Bay Estuary coastline change through the years 1895 through 2011 and determine the human and natural influences causing the changes. Historic NOAA maps were georeferenced into ArcGIS and analyzed by altering shapefiles of the estuary shoreline the years using for each selected map. Comparison maps, area change charts, and shoreline distance verses time graph were used to demonstrate the major changes. The changes were compared to a historical events timeline for the region of Coos Bay to show the correlation. The major changes on the estuary shoreline are a result of the local airport construction, and other areas that were heavily influenced by human alteration and influence. Between the years 1953 and 1940 the estuary was the most heavily altered. Only a minimal amount of the shoreline changes shows evidence of natural causes, such as erosion. With this information, the City of Coos Bay can decide on what preservation or alterations they feel are necessary to maintain the economic benefits of the estuary.