Modeling Fecal Bacteria in Oregon Coastal Streams Using Spatially Explicit Watershed Characteristics

• Main Author: Pettus, Paul Bryce
• Format: Others
• Published: PDXScholar 2013
• Subjects: Enterobacteriaceae > Oregon > Oregon Coast Range; Escherichia coli > Oregon > Oregon Coast Range; Water quality > Oregon > Oregon Coast Range > Mathematical models; Bacterial pollution of water > Oregon > Oregon Coast Range > Mathematical models; Ecological regions > Oregon > Oregon Coast Range; Bacteria; Water Resource Management
• Online Access: https://pdxscholar.library.pdx.edu/open_access_etds/1493; https://pdxscholar.library.pdx.edu/cgi/viewcontent.cgi?article=2492&context=open_access_etds

Pathogens, such as Escherichia coli and fecal coliforms, are causing the majority of water quality impairments in U.S., making up ~87% of this grouping's violations. Predicting and characterizing source, transport processes, and microbial survival rates is extremely challenging, due to the dynamic nature of each of these components. This research built upon current analytical methods that are used as exploratory tools to predict pathogen indicator counts across regional scales. Using a series of non-parametric methodologies, with spatially explicit predictors, 6657 samples from non-estuarine lotic streams were analyzed to make generalized predictions of regional water quality. 532 frequently sampled sites in the Oregon Coast Range Ecoregion, were parsed down to 93 pathogen sampling sites in effect to control for spatial and temporal biases. This generalized model was able to provide credible results in assessing regional water quality, using spatial techniques, and applying them to infrequently or unmonitored catchments. This model's 56.5% explanation of variation, was comparable to other researchers' regional assessments. This research confirmed linkages to land uses related to anthropogenic activities such as animal operations and agriculture, and general riparian conditions.