Maps

This map shows a quartile ranking within Pennsylvania of the delivered yield (load per area) of Total Phosphorus 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 Phosphorus 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.

This map shows a quartile ranking within Pennsylvania 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.

This map shows a quartile ranking within Maryland of the delivered yield (load per area) of Total Phosphorus 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 Phosphorus 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.

This map shows a quartile ranking within the Chesapeake Bay Watershed of the delivered yield (load per area) of Total Phosphorus 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 Phosphorus 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.

This map shows a quartile ranking within the Chesapeake Bay Watershed 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.

Tidal waters that are impaired for part or all of the indicated Bay segment by toxic chemicals based on each state's implementation of the Clean Water Act.

The 92-segment scheme for the Chesapeake Bay and its tidal tributaries used for dissolved oxygen and water clarity assessments in the most recent 303d/305b listing efforts of the four Bay tidal jurisdictions is documented here. The 92-segment scheme was derived from 1) the 2003 published 78-segment scheme with the addition of jurisdictional boundary lines imposed to create 89-segments, then 2) additionally includes only split segments agreed upon for the tidal James and Potomac rivers.

This map shows the Phase 4.3 Watershed Model Segmentation. The current Model Segmentation (as of July 2011) is Phase 5.3.

This map shows the historic Phase 3.0 Watershed Model Segmentation. The current version (as of July 2011) is Phase 5.3.

This map shows the historic Phase 2.0 Watershed Model Segmentation. The current version (as of July 2011) is Phase 5.3.