Maps
Browse through maps depicting Bay health and restoration, including pollution trends, public access sites and more.
Long-Term Flow-Adjusted Trends for Total Nitrogen for 31 Sites in the Chesapeake Bay Watershed
Date created: June 28, 2012Long-Term Flow-Adjusted Trends for Total Nitrogen for 31 Sites in the Chesapeake Bay Watershed, 1985-2010
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Key to Monitoring Stations (Flow Adjusted Concentrations)
Date created: June 25, 2012This map is a key to monitoring stations used to depict flow-adjusted concentration data for nitrogen, phosphorus, and sediment.
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Long-Term Flow-Adjusted Trends for Total Nitrogen (32 Sites in the Chesapeake Bay Watershed)
Date created: June 25, 2012This map shows the long-term flow-adjusted trends for total nitrogen at 32 Sites in the Chesapeake Bay Watershed from 1985-2009.
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Nitrogen Yields and Short-Term Trends Measured in Watershed Streams and Rivers
Date created: June 13, 2012Over the past 10 years, nitrogen concentration trends are downward at about half (16 out of 33) monitoring sites within the Bay watershed. The trend results indicate that in many locations, management actions, such as improved wastewater treatment and nonpoint-source pollution controls (i.e. urban stormwater runoff and agricultural runoff controls), have reduced nitrogen concentrations in streams. In addition, in the last 5 years, higher yields indicate a tendency to be located in the northern half of the watershed, conversely. lower yields are more numerous in the lower half of the watershed. The short-term flow-adjusted trends and yields indicator is calculated, and results and maps are published annually by the U.S. Geological Survey as part of a larger effort to determine loads and trends in nutrient and sediment concentrations and streamflow in the Chesapeake Bay watershed.
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Urban Sources of Total Nitrogen - Quartile Ranking within Maryland
Date created: July 14, 2011This map shows a quartile ranking within Maryland of the delivered yield (load per area) of Total Nitrogen from urban sources. Delivered yield is the amount of nutrient that is generated locally for each stream reach and weighted by the amount of in-stream loss that would occur with transport from the reach to Chesapeake Bay. The cumulative loss of nutrients from generation to delivery to the Bay is dependent on the travel time and instream-loss rate of each individual reach. This map shows estimates of Total Nitrogen based on mean conditions for the late 1990's time period using the SPARROW model from USGS. SPARROW, or SPAtially Referenced Regressions On Watershed (SPARROW) attributes, uses a nonlinear regression approach to spatially relate nutrient sources and watershed characteristics to nutrient loads of streams throughout the Chesapeake Bay watershed.
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Long-Term Flow-Adjusted Trends Total Nitrogen (32 Sites in the Chesapeake Bay Watershed) 1985-2009
Date created: March 11, 2011Over the past 24 years, nitrogen concentration trends are downward at the majority of long-term monitoring sites within the Bay watershed. The trend results indicate that in many locations, management actions, such as improved wastewater treatment and nonpoint-source pollution controls (i.e. urban stormwater runoff and agricultural runoff controls), have reduced nitrogen concentrations in streams. The flow-adjusted trends indicator is calculated, and published annually by the U.S. Geological Survey as part of a larger effort to determine loads and trends in nutrient and sediment concentrations and streamflow in the Chesapeake Bay watershed. A complete description of data analysis methods can be found in Langland, M. J., and others, Changes in streamflow and water quality in selected nontidal basins in the Chesapeake Bay watershed, 1985-2004: U.S. Geological Survey Scientific Investigations Report 2006-5178, 75 p., available online at http://pubs.usgs.gov/sir/2006/5178/.
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Nitrogen Yields and Short-Term Trends Measured in Watershed Streams and Rivers
Date created: March 10, 2011Over the past 10 years, nitrogen concentration trends are downward at about half (16 out of 33) monitoring sites within the Bay watershed. The trend results indicate that in many locations, management actions, such as improved wastewater treatment and nonpoint-source pollution controls (i.e. urban stormwater runoff and agricultural runoff controls), have reduced nitrogen concentrations in streams. In addition, in the last 5 years, higher yields indicate a tendency to be located in the northern half of the watershed, conversely. lower yields are more numerous in the lower half of the watershed. The short-term flow-adjusted trends and yields indicator is calculated, and results and maps are published annually by the U.S. Geological Survey as part of a larger effort to determine loads and trends in nutrient and sediment concentrations and streamflow in the Chesapeake Bay watershed.
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Urban Sources of Total Nitrogen - Quartile Ranking within New York
Date created: March 5, 2009This map shows a quartile ranking within New York of the delivered yield (load per area) of Total Nitrogen from urban sources. Delivered yield is the amount of nutrient that is generated locally for each stream reach and weighted by the amount of in-stream loss that would occur with transport from the reach to Chesapeake Bay. The cumulative loss of nutrients from generation to delivery to the Bay is dependent on the travel time and instream-loss rate of each individual reach. This map shows estimates of Total Nitrogen based on mean conditions for the late 1990's time period using the SPARROW model from USGS. SPARROW, or SPAtially Referenced Regressions On Watershed (SPARROW) attributes, uses a nonlinear regression approach to spatially relate nutrient sources and watershed characteristics to nutrient loads of streams throughout the Chesapeake Bay watershed.
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Urban Sources of Total Nitrogen - Quartile Ranking within Delaware
Date created: March 5, 2009This map shows a quartile ranking within Delaware of the delivered yield (load per area) of Total Nitrogen from urban sources. Delivered yield is the amount of nutrient that is generated locally for each stream reach and weighted by the amount of in-stream loss that would occur with transport from the reach to Chesapeake Bay. The cumulative loss of nutrients from generation to delivery to the Bay is dependent on the travel time and instream-loss rate of each individual reach. This map shows estimates of Total Nitrogen based on mean conditions for the late 1990's time period using the SPARROW model from USGS. SPARROW, or SPAtially Referenced Regressions On Watershed (SPARROW) attributes, uses a nonlinear regression approach to spatially relate nutrient sources and watershed characteristics to nutrient loads of streams throughout the Chesapeake Bay watershed.
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Urban Sources of Total Nitrogen - Quartile Ranking within West Virginia
Date created: March 5, 2009This map shows a quartile ranking within West Virginia of the delivered yield (load per area) of Total Nitrogen from urban sources. Delivered yield is the amount of nutrient that is generated locally for each stream reach and weighted by the amount of in-stream loss that would occur with transport from the reach to Chesapeake Bay. The cumulative loss of nutrients from generation to delivery to the Bay is dependent on the travel time and instream-loss rate of each individual reach. This map shows estimates of Total Nitrogen based on mean conditions for the late 1990's time period using the SPARROW model from USGS. SPARROW, or SPAtially Referenced Regressions On Watershed (SPARROW) attributes, uses a nonlinear regression approach to spatially relate nutrient sources and watershed characteristics to nutrient loads of streams throughout the Chesapeake Bay watershed.
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