| snippet:
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Chesapeake Bay Program Priority Agricultural Watershed Analysis Watershed-Wide HUC12 Rankings 2021 |
| summary:
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Chesapeake Bay Program Priority Agricultural Watershed Analysis Watershed-Wide HUC12 Rankings 2021 |
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["Data","Service","Map Service","ArcGIS Server"] |
| description:
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<p style='margin-bottom:0in;'><span style='font-size:16px;'>The Chesapeake Bay Program Priority Agriculture Watershed GIS Analysis (PAW 2021) created separate maps and tables of Delivered Agriculture Loading Rates (DLRag), of Nitrogen (N) and Phosphorous (P), as well as the fraction of streams carrying an agriculture-related pollutant per Chesapeake Bay (CB) twelve-digit coded Hydrological Unit (USGS and USDA-NRCS-National Cartographic and Geospatial Center's (NCGC): </span></p><p style='margin-bottom:0in;'><a href='https://www.nrcs.usda.gov/wps/portal/nrcs/main/national/water/' target='_blank'>https://www.nrcs.usda.gov/wps/portal/nrcs/main/national/water/</a><span style='font-size:16px;'>) (HUC). DLRag values were calculated using the SPARROW 2018 (https://doi.org/10.3133/sir20185051) release of modeled N and P pollutant movement between hydrologic catchments within the Chesapeake Bay watershed along with USGS National Land Cover data (NLCD 2011). Observed stream pollutant data was available through consolidated State 303(d) reports in the EPA ATTAINS database (</span><a href='https://www.epa.gov/waterdata/attains' target='_blank'>https://www.epa.gov/waterdata/attains</a><span style='font-size:16px;'>), for which each state defines its own set of criteria of sampled stream pollutants that are likely to be related to agricultural sources.</span></p><p style='margin-bottom:0in;'><span style='font-size:16px;'><br /></span></p><p style='margin-bottom:0in;'><span style='font-size:16px;'>Each SPARROW catchment is represented by one record in the SPARROW database table as well as spatially by its corresponding catchment GIS polygon. Each catchment polygon is nested within an HUC polygon which is also referenced in each catchment table record. Some SPARROW catchment records show a drainage area value that is larger than the HUC in which it nests. This is true of catchments that represent large rivers or streams. Such catchments were identified as “Non-Local” and were removed from the universe of catchments used to summarize stream lengths within each HUC. </span></p><p style='margin-bottom:0in;'><span style='font-size:16px;'><br /></span></p><p style='margin-bottom:0in;'><span style='font-size:16px;'>Of the remaining “Local Catchments”, moreover, some were further assigned a designation as “Agriculture Catchments” (AgCats) which are those with Nitrogen and Phosphorous loadings having mostly agricultural sources, computed from SPARROW tables as follows:</span></p><div><div><font size='2'>AgCat = Percent Catchment AG for a SPARROW NHD catchment = </font><span style='font-size:small;'>((Total N Ag load)/(Total N load) + (Total P Ag load)/(Total P load))/2 > 0.5</span></div><div><font size='2'>where:<span style=''> </span></font></div><div><font size='2'> Total N Ag load kg = ACCL_s4n + ACCL_s5n + ACCL_s6n </font></div><div><font size='2'> Total P Ag load kg = ACCL_s3p + ACCL_s4p </font></div><div><font size='2'> Total N load = ACCL = Sum(ACCL_s1, ACCL_s2, … ACCL_s7) = All N Loads</font></div><div><font size='2'> Total P load = ACCL = Sum(ACCL_s1, ACCL_s2, … ACCL_s5) = All P Loads</font></div><div><font size='2'>and where:<span style=''> </span></font></div><div><font size='2'> ACCL_s4n = Accumulated N load from farm fertilizer (kg) </font></div><div><font size='2'> ACCL_s5n = Accumulated N load from manure (kg)</font></div><div><font size='2'> ACCL_s6n = Accumulated N load from nitrogen fixing crops (kg)</font></div><div><font size='2'> ACCL_s3p = Accumulated P load from farm fertilizer (kg) </font></div><div><font size='2'> ACCL_s4p = Accumulated P load from manure (kg)</font></div></div><div><div>To determine the Delivered Agriculture Loading Rate for Nitrogen (DLRag_N) for a HUC the Total N Ag load for N, as defined in the formula below were summed and the result was divided by the number of NLCD 2011 Crop and Pasture hectares tabulated per HUC. The same calculation was performed separately for DLRag_P per HUC</div><div><font size='2'>Delivered Ag Loading Rate N = (DLRag_N) = Total Nag Load / Total NLCD HUC ag area</font></div><div><font size='2'>Delivered Ag Loading Rate P = (DLRag_P) = Total Pag Load / Total NLCD HUC ag area</font></div><div><font size='2'>Where:</font></div><div><font size='2'> Total Nag load* = dincl_s4n + dincl_s5n + dincl_s6n</font></div><div><font size='2'> Total Pag load* = dincl_s3p + dincl_s4p<span style=''> </span> </font></div><div><font size='2'>and where:<span style=''> </span></font></div><div><font size='2'> dincl_s4n* = Delivered N load from farm fertilizer </font></div><div><font size='2'> dincl_s5n* = Delivered N load from manure</font></div><div><font size='2'> dincl_s6n* = Delivered N load from nitrogen fixing crops </font></div><div><font size='2'> dincl_s3p* = Delivered P load from farm fertilizer </font></div><div><font size='2'> dincl_s4p* = Delivered P load from manure </font></div><div><font size='2'>* Kg summed to HUC12 values from all, local and non-local, SPARROW catchment records</font></div></div><div><br /></div><div><font size='3' style=''><div style=''>Percent Rank (PR) of these values, DLRag_N_PR and DLRag_P_PR, was calculated relative to all HUCs across the watershed. A set of Percent Rank values for each States’ DLRag values were also calculated.</div><div style=''><br /></div><div style=''>A second set of maps was created by applying the above defined AgCats to the stream data. ATTAINS assessed streams were identified that had at least one agriculture-related pollutant, as defined by each State. Of these Ag-Impaired streams, only those that were found within an AgCat were selected. This was because Ag-Related stream pollutants could be found which originated in city parks and other non-agricultural stream reaches. The combined length of such Ag-Impaired streams per HUC was divided by the sum of all local ATTAINS assessed catchment stream lengths found within the same HUC. This resulted in a map of the fraction of All-Assessed HUC local stream lengths that were ag-impaired and fell within an AgCat.</div><div style=''><br /></div><div style=''>The resultant data layers were created using ESRI ArcGIS Pro Version 2.7.2 software. It consists of two feature class File Geodatabase entries, one for the HUC12 Percent Rankings Watershed-Wide (WW) and one for the State-Specific (SS) State HUC12 rankings, named as PAW_WW_2021 and PAW_SS_2021, respectively. The Attribute Table Columns for these features are as follows:</div></font></div><div><br /><div><span style='text-indent:0.5in; font-weight:400; font-size:9pt; color:windowtext;'><span style='font-size:9.0pt; font-family:"Calibri",sans-serif;'><table border='0' cellpadding='0' cellspacing='0' style='width:491.3pt; border-collapse:collapse;' width='655'>
<tbody><tr style='height:14.0pt;'>
<td nowrap='' style='width:1.4in; border:solid black 1.0pt; padding:0in 5.4pt 0in 5.4pt; height:14.0pt;' width='134'>
<p style='margin-bottom:0in;'><b><u><span style='font-size:10.0pt; color:black;'>Field Name</span></u></b></p>
</td>
<td nowrap='' style='width:390.5pt; border:solid black 1.0pt; border-left:none; padding:0in 5.4pt 0in 5.4pt; height:14.0pt;' width='521'>
<p style='margin-bottom:0in;'><b><u><span style='font-size:10.0pt; color:black;'>Description</span></u></b></p>
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<tr style='height:14.0pt;'>
<td nowrap='' style='width:1.4in; border:solid black 1.0pt; border-top:none; background:#D9D9D9; padding:0in 5.4pt 0in 5.4pt; height:14.0pt;' width='134'>
<p style='margin-bottom:0in;'><span style='font-size:10.0pt; color:black;'>HUC12 or HUC12_ST</span></p>
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<td nowrap='' style='width:390.5pt; border-top:none; border-left:none; border-bottom:solid black 1.0pt; border-right:solid black 1.0pt; background:#D9D9D9; padding:0in 5.4pt 0in 5.4pt; height:14.0pt;' width='521'>
<p style='margin-bottom:0in;'><span style=''><font size='2'>Twelve-Digit
Hydrologic Unit Name or HUC Name with State Suffix</font></span><br /></p>
</td>
</tr>
<tr style='height:14.0pt;'>
<td nowrap='' style='width:1.4in; border:solid black 1.0pt; border-top:none; padding:0in 5.4pt 0in 5.4pt; height:14.0pt;' width='134'>
<p style='margin-bottom:0in;'><span style=''><font size='3'>WW_AgImp_Fract</font></span><br /></p>
</td>
<td nowrap='' style='width:390.5pt; border-top:none; border-left:none; border-bottom:solid black 1.0pt; border-right:solid black 1.0pt; padding:0in 5.4pt 0in 5.4pt; height:14.0pt;' width='521'>
<p style='margin-bottom:0in;'><span style='font-size:11pt;'>Watershed-Wide
Ag Impaired Stream Length Fraction</span><br /></p>
</td>
</tr>
<tr style='height:14.0pt;'>
<td nowrap='' style='width:1.4in; border:solid black 1.0pt; border-top:none; background:#D9D9D9; padding:0in 5.4pt 0in 5.4pt; height:14.0pt;' width='134'>
<p style='margin-bottom:0in;'><span style='font-size:11pt;'>WW_DLRag_N</span><br /></p>
</td>
<td nowrap='' style='width:390.5pt; border-top:none; border-left:none; border-bottom:solid black 1.0pt; border-right:solid black 1.0pt; background:#D9D9D9; padding:0in 5.4pt 0in 5.4pt; height:14.0pt;' width='521'>
<p style='margin-bottom:0in;'><span style='font-size:11pt;'>Watershed-Wide
Delivered Loading Rate for Nitrogen</span><br /></p>
</td>
</tr>
<tr style='height:14.0pt;'>
<td nowrap='' style='width:1.4in; border:solid black 1.0pt; border-top:none; padding:0in 5.4pt 0in 5.4pt; height:14.0pt;' width='134'>
<p style='margin-bottom:0in;'><span style='font-size:11pt;'>WW_DLRag_PR_N</span><br /></p>
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<td nowrap='' style='width:390.5pt; border-top:none; border-left:none; border-bottom:solid black 1.0pt; border-right:solid black 1.0pt; padding:0in 5.4pt 0in 5.4pt; height:14.0pt;' width='521'>
<p style='margin-bottom:0in;'><span style='font-size:11pt;'>Watershed-Wide
Delivered Loading Rate Percent Rank for Nitrogen</span><br /></p>
</td>
</tr>
<tr style='height:14.0pt;'>
<td nowrap='' style='width:1.4in; border:solid black 1.0pt; border-top:none; background:#D9D9D9; padding:0in 5.4pt 0in 5.4pt; height:14.0pt;' width='134'>
<p style='margin-bottom:0in;'><span style='font-size:11pt;'>WW_DLRag_P</span><br /></p>
</td>
<td nowrap='' style='width:390.5pt; border-top:none; border-left:none; border-bottom:solid black 1.0pt; border-right:solid black 1.0pt; background:#D9D9D9; padding:0in 5.4pt 0in 5.4pt; height:14.0pt;' width='521'>
<p style='margin-bottom:0in;'><span style='font-size:11pt;'>Watershed-Wide
Delivered Loading Rate for Phosphorous</span><br /></p>
</td>
</tr>
<tr style='height:14.0pt;'>
<td nowrap='' style='width:1.4in; border:solid black 1.0pt; border-top:none; padding:0in 5.4pt 0in 5.4pt; height:14.0pt;' width='134'>
<p style='margin-bottom:0in;'><span style='font-size:11pt;'>WW_DLRag_PR_P</span><br /></p>
</td>
<td nowrap='' style='width:390.5pt; border-top:none; border-left:none; border-bottom:solid black 1.0pt; border-right:solid black 1.0pt; padding:0in 5.4pt 0in 5.4pt; height:14.0pt;' width='521'>
<p style='margin-bottom:0in;'><span style='font-size:11pt;'>Watershed-Wide
Delivered Loading Rate Percent Rank for Phosphorous</span><br /></p>
</td>
</tr>
<tr style='height:14.0pt;'>
<td nowrap='' style='width:1.4in; border:solid black 1.0pt; border-top:none; background:#D9D9D9; padding:0in 5.4pt 0in 5.4pt; height:14.0pt;' width='134'>
<p style='margin-bottom:0in;'><span style='font-size:11pt;'>SS_DLRag_N</span><br /></p>
</td>
<td nowrap='' style='width:390.5pt; border-top:none; border-left:none; border-bottom:solid black 1.0pt; border-right:solid black 1.0pt; background:#D9D9D9; padding:0in 5.4pt 0in 5.4pt; height:14.0pt;' width='521'>
<p style='margin-bottom:0in;'><span style='font-size:11pt;'>State
Specific Delivered Loading Rate for Nitrogen</span><br /></p>
</td>
</tr>
<tr style='height:14.0pt;'>
<td nowrap='' style='width:1.4in; border:solid black 1.0pt; border-top:none; padding:0in 5.4pt 0in 5.4pt; height:14.0pt;' width='134'>
<p style='margin-bottom:0in;'><span style='font-size:11pt;'>SS_DLRag_PR_N</span><br /></p>
</td>
<td nowrap='' style='width:390.5pt; border-top:none; border-left:none; border-bottom:solid black 1.0pt; border-right:solid black 1.0pt; padding:0in 5.4pt 0in 5.4pt; height:14.0pt;' width='521'>
<p style='margin-bottom:0in;'><span style='font-size:11pt;'>State
Specific Delivered Loading Rate for Nitrogen Percent Rank</span><br /></p>
</td>
</tr>
<tr style='height:14.0pt;'>
<td nowrap='' style='width:1.4in; border:solid black 1.0pt; border-top:none; background:#D9D9D9; padding:0in 5.4pt 0in 5.4pt; height:14.0pt;' width='134'>
<p style='margin-bottom:0in;'><span style='font-size:11pt;'>SS_DLRag_P</span><br /></p>
</td>
<td nowrap='' style='width:390.5pt; border-top:none; border-left:none; border-bottom:solid black 1.0pt; border-right:solid black 1.0pt; background:#D9D9D9; padding:0in 5.4pt 0in 5.4pt; height:14.0pt;' width='521'>
<p style='margin-bottom:0in;'><span style='font-size:11pt;'>State
Specific Delivered Loading Rate for Phosphorous </span><br /></p>
</td>
</tr>
<tr style='height:14.0pt;'>
<td nowrap='' style='width:1.4in; border:solid black 1.0pt; border-top:none; padding:0in 5.4pt 0in 5.4pt; height:14.0pt;' width='134'>
<p style='margin-bottom:0in;'><span style='font-size:11pt;'>SS_DLRag_PR_P</span><br /></p></td><td nowrap='' style='width:390.5pt; border-top:none; border-left:none; border-bottom:solid black 1.0pt; border-right:solid black 1.0pt; padding:0in 5.4pt 0in 5.4pt; height:14.0pt;' width='521'><span style='font-size:11pt;'>State
Specific Delivered Loading Rate for Phosphorous Percent Rank</span></td></tr>
</tbody></table><br /></span></span></div></div> |
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| title:
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Chesapeake Bay Program Priority Agricultural Watershed Analysis Watershed-Wide HUC12 Rankings 2021 |
| type:
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Map Service |
| url:
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| tags:
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["Chesapeake Bay Watershed","SPARROW","NHD","HUC12","NLCD","ATTAINS","Land Cover","Land Use","Estuary","Sediment Load","Hydrology","Pollution Diet","Nutrients","Nitrate","Nitrogen","Phosphorus","Loads and Trends","Anthropogenic Disturbance","Surface Water","Water Quality","Stream Health","BMP","Agriculture","Pollution","Rivers & Streams","Sediment","Stormwater Runoff","Stewardship","Land Conservation","Modeling","Monitoring","Land Resources"] |
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en-US |
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PAW_WW_2021 |
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Albers_Equal_Area_Conic_USGS_CONUS_NAD83 |