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Date Permissions Signed


Date of Award


Document Type

Masters Thesis

Degree Name

Master of Science (MS)


Environmental Sciences

First Advisor

Matthews, Robin A., 1952-

Second Advisor

Homann, Peter S., 1953-

Third Advisor

Bodensteiner, Leo R., 1957-


The purpose of my study was to find reliable patterns in the data that linked watershed characteristics to water quality. The project area was regional in scope, spanning two very different ecoregions, involving 50 lakes many of which have been sampled for 7 years. I found highly significant correlations (Kendall's tau > 0.500, pvalue < 0.001) between total phosphorus, chlorophyll α, total nitrogen, and turbidity. Total phosphorus, chlorophyll α, total nitrogen, and turbidity also strongly correlated with mean and maximum lake depths. I also found highly significant correlations between watershed area, fetch, road length, and population. Road length and population were the parameters that best described residential development in my study. By evaluating lake water quality with regard to total phosphorus, chlorophyll α, and using road length and population as indicators of development, I identified lakes that were at-risk due to development within the watersheds and the likelihood of nutrient resuspension. The most at-risk lake was Reed Lake. Currently Reed Lake is at the high end of the mesotrophic range, but it is at risk of becoming more permanently eutrophic due to the pressures of development on the water quality exacerbated by the likelihood of nutrient resuspension. Using clustering analysis based on principal components, the watersheds in my study formed three stable groups that were related to water quality and lake and watershed morphology. The extent to which soils affect water quality in these lakes was not fully revealed by the results of my work and is worthy of further investigation.





Western Washington University

OCLC Number


Subject – LCSH

Water quality--Washington (State), Western; Watersheds--Washington (State), Western; Landforms--Washington (State), Western; Land use--Washington (State), Western

Geographic Coverage

Washington (State), Western




masters theses




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