Integrated Trends Analysis Team
Upcoming Meetings
July 27, 2022
10:00 am - 12:00 pm
Integrated Trends Analysis Team Meeting, July 2022
Download calendar file (.ics)August 24, 2022
10:00 am - 12:00 pm
Integrated Trends Analysis Team Meeting, August 2022
Download calendar file (.ics)September 28, 2022
10:00 am - 12:00 pm
Integrated Trends Analysis Team Meeting, September 2022
Download calendar file (.ics)Scope and Purpose
The Integrated Trends Analysis Team aims to combine the efforts of the Chesapeake Bay Program analysts with those of investigators in governmental, academic, and non-profit organizations to identify potential research synergies and collaborations that will enhance our understanding of spatial and temporal patterns in water quality.
Specific Goals:
(1) Gather researchers and analysts from various governmental, academic, non-profit, and private organizations for biannual meetings to identify the broad scope of on-going work related to trends and patterns of water quality in the Chesapeake watershed and estuary.
(2) Discover previously un-identified linkages among the ongoing research activities of participating individuals and organizations.
(3) Develop a standard set of analysis tools that can be applied in any relevant ecosystem within the Chesapeake watershed and estuary.
(4) Foster increased collaboration and awareness of ongoing research.
(5) Provide a forum for bringing findings to the broader Chesapeake Bay management community.
Membership in the Integrated Trends Analysis Team is currently not formally defined. If you would like to receive invitations to upcoming meetings, contact Alexander Gunnerson (agunnerson@chesapeakebay.net) to request that your name and email address be added to the Team's distribution list.
Projects and Resources
Tributary Summaries
The Chesapeake Bay Program and its partners produce tributary basin summary reports for the Bay’s 12 major tributaries using tidal monitoring data from more than 130 monitoring stations throughout the mainstem and tidal portions of the Bay. These reports use water quality sample data to summarize 1) How tidal water quality (TN, TP, DO, Chlorophyll a, Secchi Depth) has changed over time, 2) How and which factors may influence water quality change over time, and 3) Recent research connecting observed changes in aquatic conditions to its drivers.
These documents can be found on the CAST webpage here.
Maps of 2020 Tidal Water Quality Change
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Tidal Water Quality Change - 2020 (2.67 MB)
1. Long-Term Change
Observed change in water quality by station from the beginning of the period to 2020.
- Surface Total Nitrogen, Annual 1985-2020 (462.47 KB)
- Surface Total Phosphorus, Annual 1985-2020 (470.11 KB)
- Surface Chlorophyll-a, Spring 1985-2020 (466.4 KB)
- Surface Chlorophyll-a, Summer 1985-2020 (488.69 KB)
- Secchi Depth, Annual 1985-2020 (449.67 KB)
- Surface Total Suspended Solids, Annual 1999-2020 (444.54 KB)
- Surface Water Temperature, Annual 1985-2020 (482.07 KB)
- Bottom Dissolved Oxygen, Summer 1985-2020 (467.25 KB)
2. Long-Term Flow-Adjusted Change
Change in water quality by station computed under the condition of average freshwater flow into the Chesapeake Bay over the long-term. This approach answers the question: “What would the change in water quality have been if flow had been average?”
- Surface Total Nitrogen, Flow-Adjusted, Annual 1985-2020 (464.53 KB)
- Surface Total Phosphorus, Flow-Adjusted, Annual 1985-2020 (463.86 KB)
- Surface Chlorophyll-a, Flow-Adjusted, Spring 1985-2020 (453.73 KB)
- Surface Chlorophyll-a, Flow-Adjusted, Summer 1985-2020 (464.17 KB)
- Secchi Depth, Flow-Adjusted, Annual 1985-2020 (452.02 KB)
- Surface Total Suspended Solids, Flow-Adjusted, Annual 1999-2020 (442.16 KB)
- Surface Water Temperature, Flow-Adjusted, Annual 1985-2020 (485.2 KB)
- Bottom Dissolved Oxygen, Flow-Adjusted, Summer 1985-2020 (476.98 KB)
3. Short-Term Change
Observed change in water quality by station over the last 10 years.
- Surface Total Nitrogen, Annual 2010-2020 (409.42 KB)
- Surface Total Phosphorus, Annual 2010-2020 (420.18 KB)
- Surface Chlorophyll-a, Spring 2010-2020 (419.55 KB)
- Surface Chlorophyll-a, Summer 2010-2020 (412.29 KB)
- Secchi Depth, Annual 2010-2020 (411.76 KB)
- Surface Total Suspended Solids, Annual 2010-2020 (435.74 KB)
- Surface Water Temperature, Annual 2010-2020 (441.64 KB)
- Bottom Dissolved Oxygen, Summer 2010-2020 (436.98 KB)
4. Short-Term Flow-Adjusted Change
Observed change in water quality computed under the condition of average freshwater flow into the Chesapeake Bay over the last 10 years.
- Surface Total Nitrogen, Flow-Adjusted, Annual 2010-2020 (443.46 KB)
- Surface Total Phosphorus, Flow-Adjusted, Annual 2010-2020 (416.5 KB)
- Surface Chlorophyll-a, Flow-Adjusted, Spring 2010-2020 (418.88 KB)
- Surface Chlorophyll-a, Flow-Adjusted, Summer 2010-2020 (419.39 KB)
- Secchi Depth, Flow-Adjusted, Annual 2010-2020 (416.76 KB)
- Surface Total Suspended Solids, Flow-Adjusted, Annual 2010-2020 (429.34 KB)
- Surface Water Temperature, Flow-Adjusted, Annual 2010-2020 (455.21 KB)
- Bottom Dissolved Oxygen, Flow-Adjusted, Summer 2010-2020 (456.19 KB)
Additional 2020 Results
Includes other depths and parameters not included in sections 1-4 above.
Bottom Layer (TN, TP, and Temperature)
Please reach out to Alex Gunnerson (agunnerson@chesapeakebay.net) or Rebecca Murphy (rmurphy@chesapeakebay.net) for the 2019 results.
GAM Documentation
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Draft-GAM Method for Chesapeake 5-10-18 (1.06 MB)
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Appendix 1A Baytrends Quick Start Instructions (2.2 MB)
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Appendix 2.1A example R Package Files (852.74 KB)
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Appendix 2.3A - QW Data Format (164 KB)
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Appendix 2.4A Ex GAM Models (690.32 KB)
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Appendix 2.5A Percent Change (519.04 KB)
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Appendix 2.6A Censored Data Approaches (618.3 KB)
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Appendix 2.6B Summary of Censoring (582.23 KB)
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Appendix 2.6C Censoring Scenarios (8.24 MB)
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Appendix 2.7A Lab Change Approach (693.63 KB)
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Appendix 2.8A Create Seasonally Detrended Flow and salinity Data sets (288 KB)
ITAT documents
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Synthesis of Watershed Trends and Results - Jimmy Webber, John Clune, Alex Soroka (USGS) (15.57 MB)
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Measuring and Explaining Trends in Water Quality - Jeni Keisman (240.31 KB)
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Water Quality Criteria Attainment Patterns - Mindy Ehrich (3 MB)
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GAM Development Briefing Oct 2015 - Rebecca Murphy (1.72 MB)
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Monitoring Data in Support of Mid-Point Assessment - Doug Moyer, Joel Blomquist, Jeni Keisman (7.27 MB)
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SK/GAM Comparison - Kyle Hinson (940.52 KB)
ITAT Web Publishing Policy
This document outlines the policies that the Integrated Trends Analysis Team will follow in publishing meeting presentation materials for a public audience.
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Web Publishing Policy (91.3 KB)
Publications
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December 21, 2021
Nutrient Improvements in Chesapeake Bay: Direct Effect of Load Reductions and Implications for Coastal Management. Rebecca R. Murphy, Jennifer Keisman, Jon Harcum, Renee R. Karrh, Mike Lane, Elgin S. Perry, and Qian Zhang
Link to the artice: https://pubs.acs.org/doi/10.1021/acs.est.1c05388
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March 28, 2019
Murphy, R.R., Perry, E., Harcum, J. and Keisman, J. 2019. A Generalized Additive Model approach to evaluating water quality: Chesapeake Bay case study. Environmental Modelling and Software 118: 1-13. https://doi.org/10.1016/j.envsoft.2019.03.027
Documentation of GAM approach used for tidal trends in Chesapeake Bay. Link to the final manuscript, or contact rmurphy@chesapeakebay.net for the final version.
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June 30, 2016
ITAT June 2016 Newsletter
The June 2016 newsletter contains important and informative updates regarding the synethesis efforts and recent publications by team members and interested parties. For more information and to submit work that you would...