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Summary of trends and status analysis for flow, nutrients, and sediments at selected nontidal sites, Chesapeake Bay basin, 1985-99

Open-File Report 2001-73
By: , , , and 
https://doi.org/10.3133/ofr0173

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Abstract

Water-quality and flow data from 31 sites in nontidal portions of the Chesapeake Bay Basin were analyzed to document annual nutrient and sediment loads and trends for the period 1985 through 1999 as part of an annual reevaluation and reporting for the Chesapeake Bay Program. Annual loads were estimated by use of the U.S. Geological Survey ESTIMATOR model. Trends were estimated using linear regression. Trends were reported for monthly mean flow, monthly load, flow-adjusted concentration, and flow-weighted concentration. Median yields and concentrations were calculated to help facilitate comparisons between basins. The drought of 1999 had pronounced effects on trend results. The trend in flow increased at 4 of the 31 sites, 8 fewer sites than in 1998. Ten less significant trends were estimated for nutrient and sediment loads compared to 1985-98. Trends in flow-weighted and flow-adjusted concentrations varied little by nutrient species and geographic location. Trends were generally downward or not significant for both the nitrogen and phosphorus species throughout the Chesapeake Bay Basin. Trends in flow-adjusted concentration indicated downward trends at most sites for nutrients and about half the sites for sediments, an indication that management actions are reducing nutrient and sediment concentrations.

Suggested Citation

Langland, M.J., Edwards, R.E., Sprague, L.A., and Yochum, S.E., 2001, Summary of trends and status analysis for flow, nutrients, and sediments at selected nontidal sites, Chesapeake Bay basin, 1985-99: U.S. Geological Survey Open-File Report 2001–0073, 49 p., https://pubs.er.usgs.gov/publication/ofr0173.

ISSN: 2331-1258 (online)

Table of Contents

  • Abstract
  • Introduction
  • Methods
  • Trends
  • Status
  • Summary
  • References cited
  • Appendix 1. Trends in streamflow and load data for 9 River Input Monitoring Program sites and 22 Multi-Agency Nontidal Program sites in the Chesapeake Bay Watershed
  • Appendix 2. Trends in flow-weighted concentration data for 9 River Input Monitoring Program sites and 22 Multi-Agency Nontidal Program sites in the Chesapeake Bay Watershed
  • Appendix 3. Trends in flow-adjusted coencentration data for 9 River Input Monitoring Program sites and 22 Multi-Agency Nontidal Program sites in the Chesapeake Bay Watershed
Publication type Report
Publication Subtype USGS Numbered Series
Title Summary of trends and status analysis for flow, nutrients, and sediments at selected nontidal sites, Chesapeake Bay basin, 1985-99
Series title Open-File Report
Series number 2001-73
DOI 10.3133/ofr0173
Year Published 2001
Language English
Publisher U.S. Geological Survey
Publisher location Reston, VA
Contributing office(s) Pennsylvania Water Science Center
Description 49 p.
Online Only (Y/N) Y
Additional Online Files (Y/N) N
Google Analytic Metrics Metrics page
Additional publication details