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Base Flow in the Great Lakes Basin

By: B.P. Neff, S.M. Day, A.R. Piggott, and L.M. Fuller


U.S. Geological Survey Scientific Investigations Report 2005-5217

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Hydrograph separations were performed using the PART, HYSEP 1, 2, and 3, BFLOW and UKIH methods on 104,293 years of daily streamflow records from 3,936 streamflow-gaging stations in Ontario, Canada and the eight Great Lakes States of Illinois, Indiana, Michigan, Minnesota, New York, Ohio, Pennsylvania, and Wisconsin to estimate base-flow index (BFI) and base flow. BFI ranged an average of 0.24 BFI depending on which hydrograph-separation method was used. BFI data from 959 selected streamflow-gaging stations with a combined 28,784 years of daily streamflow data were used to relate BFI to surficial geology and the proportion of surface water within the gaged watersheds. This relation was then used to derive estimates of BFI throughout the Great Lakes, Ottawa River, and upper St. Lawrence River Basins at a scale of 8-digit hydrologic unit code (HUC) watersheds for the U.S. and tertiary watersheds in Canada. This process was repeated for each of the six hydrograph-separation methods used. When applied to gaged watersheds, model results predicted observed base flow within 0.2 BFI up to 94 percent of the time. Estimates of long-term (length of streamflow record) average annual streamflow in each HUC and tertiary watershed were calculated and used to determine average annual base flow from BFI estimates. Possibilities for future study based on results from this study include long-term trend analysis of base flow and improving the scale at which base-flow estimates can be made.


Neff, B.P., S.M. Day, A.R. Piggott and L.M. Fuller, 2005, Base Flow in the Great Lakes Basin, Date Posted: November 29, 2005: U.S. Geological Survey Scientific Investigations Report 2005-5217, 23 p. []




Purpose and Scope

Description of Study Area

Hydrogeologic Setting


Base-Flow Calculation

Selection of Gages Used for Model Development

Relation of Base-Flow Index to Landscape

G-Model Development

G-SW Model Development

Model Coefficents and Attenuation Function Parameters

Conversion from Base-Flow Index to Base Flow

Base flow in the Great Lakes Basin

Gaged Areas

Correlation of Base-Flow Index with Model Predictions

Ungaged Areas

Model Limitations

Suggestions for Possible Future Study

Summary and Conclusions


Literature Cited

Appendix A: Hydrologic Data [4 CD-ROMs]


Disk one [331 MB]

Disk two [535 MB]

Disk three [592 MB]

Disk four [449 MB]

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