Colby Fisher

Date of Award


Document Type



Environmental Resources Engineering

Thesis Advisor

Theodore A. Endreny


In recent years, excess phosphorus in lake water columns has triggered the nuisance growth of the filamentous green algae, Cladophora glomerata, in the near-shore areas of Lakes Erie, Michigan and Ontario. One approach to limiting nuisance Cladophora blooms is to build a systems model of the watershed hydrologic loading and aquatic biogeochemical cycling to help managers identify phosphorus control options. In this research we built the Contributing Area-Dispersal Area (CADA) weighted Export Coefficient (EC) watershed runoff model in ArcGIS to identify watershed areas delivering the greatest phosphorus loads. We tested the CADA EC model in the Lake Ontario basin using 30 arc-second digital elevation models, remotely sensed land cover classifications, and regional phosphorus export coefficients. The watershed model will be coupled with a proven aquatic biogeochemical cycling model to better assist management of nuisance algal growth along lakeshores. This simulation tool has the potential to improve nutrient tracking and eutrophication management, which may result in a much greater chance for preserving sensitive aquatic ecosystems.

Included in

Hydrology Commons