Modeling drivers of phosphorus loads in Chesapeake Bay tributaries and inferences about long-term change

Science of the Total Environment
By: , and 

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Abstract

Causal attribution of changes in water quality often consists of correlation, qualitative reasoning, listing references to the work of others, or speculation. To better support statements of attribution for water-quality trends, structural equation modeling was used to model the causal factors of total phosphorus loads in the Chesapeake Bay watershed. By transforming, scaling, and standardizing variables, grouping similar sites, grouping some causal factors into latent variable models, and using methods that correct for assumption violations, we developed a structural equation model to show how causal factors interact to produce total phosphorus loads. Climate (in the form of annual total precipitation and the Palmer Hydrologic Drought Index) and anthropogenic inputs are the major drivers of total phosphorus load in the Chesapeake Bay watershed. Increasing runoff due to natural climate variability is offsetting purposeful management actions that are otherwise decreasing phosphorus loading; consequently, management actions may need to be reexamined to achieve target reductions in the face of climate variability.

Additional publication details

Publication type Article
Publication Subtype Journal Article
Title Modeling drivers of phosphorus loads in Chesapeake Bay tributaries and inferences about long-term change
Series title Science of the Total Environment
DOI 10.1016/j.scitotenv.2017.10.173
Volume 616–617
Year Published 2018
Language English
Publisher Elsevier
Contributing office(s) North Dakota Water Science Center
Description 8 p.
First page 1423
Last page 1430
Country United States
Other Geospatial Chesapeake Bay