Maps

The 2011 Dissolved Oxygen Indicator showing Percent of Goal Achieved using the three year analysis method.

The map shows the average Index of Biological Integrity Score for phytoplankton by monitoring station.

The Phytoplankton (Index of Biological Integrity) map shows the percent of the goal achieved by CBP Monitoring Segment.

This map shows the 2011 indicator status of the Benthic Index of Biological Integrity by station.

This map shows the percent of the Index of Biological Integrity indicator goal achieved by segment.

This 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.

The map shows the average Index of Biological Integrity Score for phytoplankton by monitoring station.

The Phytoplankton (Index of Biological Integrity) map shows the percent of the goal achieved by CBP Monitoring Segment.

This map shows the percent of the Index of Biological Integrity indicator goal achieved by segment.

Over the past 24 years, sediment concentration trends show mixed responses among the monitoring sites with the majority of results being not significant or downward. The trend results indicate that in some locations, management actions, such as erosion and runoff controls have reduced sediment 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/