USGS: WRTDS
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Title
| Weighted Regressions on Time, Discharge, and Season (WRTDS), with an Application to Chesapeake Bay River Inputs |
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Author
| Hirsch, R.M., Moyer, D.L., and Archfield, S.A |
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Abstract/Summary Statement
| A new approach to the analysis of long-term surface water-quality data is proposed and implemented. The goal of this approach is to increase the amount of information that is extracted from the types of rich water-quality datasets that now exist. The method is formulated to allow for maximum flexibility in representations of the long-term trend, seasonal components, and discharge-related components of the behavior of the water-quality variable of interest. It is designed to provide internally consistent estimates of the actual history of concentrations and fluxes as well as histories that eliminate the influence of year-to-year variations in streamflow. The method employs the use of weighted regressions of concentrations on time, discharge, and season. Finally, the method is designed to be useful as a diagnostic tool regarding the kinds of changes that are taking place in the watershed related to point sources, groundwater sources, and surface-water nonpoint sources. The method is applied to datasets for the nine large tributaries of Chesapeake Bay from 1978 to 2008. The results show a wide range of patterns of change in total phosphorus and in dissolved nitrate plus nitrite. These results should prove useful in further examination of the causes of changes, or lack of changes, and may help inform decisions about future actions to reduce nutrient enrichment in the Chesapeake Bay and its watershed. |
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Table of Contents
| Sections include: Abstract Introduction Seven Desired Attributes of a New Approach for the Analysis of Long-Term Water-Quality Data The Method: Weighted Regressions on Time, Discharge, and Season Model Results and Sensitivities Suggested Topics for Exploration and Future Improvements in WRTDS Conclusions Acknowledgments Literature Cited Supporting Information |
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Citation
| Hirsch, Robert M., Douglas L. Moyer, and Stacey A. Archfield, 2010. Weighted Regressions on Time, Discharge, and Season (WRTDS), With an Application to Chesapeake Bay River Inputs. Journal of the American Water Resources Association (JAWRA) 46(5):857-880. DOI: 10.1111/j.1752-1688.2010.00482.x |
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Method Source
| USGS |
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Source Organization Country
| USA |
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Publication Year
| 2010 |
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Special Notes
| This paper is intended to introduce a new approach to water-quality trend analysis. Link to article without appendixes, available at http://onlinelibrary.wiley.com/doi/10.1111/j.1752-1688.2010.00482.x/pdf |
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Item Type
| Journal Article |
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Publication Source Type
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Journal |
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Purpose
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Data analysis |
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Design or Data Analysis Objectives
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Flow statistics Flow-adjusted concentrations Interpolate concentrations Loads & fluxes Relationships & correlations Revisit Temporal trends |
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Complexity
| Medium |
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Media Emphasized
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Surface Water |
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Media Subcategory
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Special Topics
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