Description: <p style="margin:12pt 0in 0in; background-image:initial; background-position:initial; background-size:initial; background-repeat:initial; background-attachment:initial; background-origin:initial; background-clip:initial;"><span style="font-size:12pt; background-image:initial; background-position:initial; background-size:initial; background-repeat:initial; background-attachment:initial; background-origin:initial; background-clip:initial;">There
are several fields within this layer that have been calculated. Below is
an explanation detailing how the numbers are derived:</span></p><p style="margin:12pt 0in 0in 0.5in; text-indent:-0.25in; background-image:initial; background-position:initial; background-size:initial; background-repeat:initial; background-attachment:initial; background-origin:initial; background-clip:initial;"><span style="font-size:10pt; font-family:Symbol;">·<span style="font-variant-numeric:normal; font-variant-east-asian:normal; font-variant-alternates:normal; font-kerning:auto; font-feature-settings:normal; font-variant-position:normal; font-stretch:normal; font-size:7pt; font-family:&quot;Times New Roman&quot;;">
</span></span><b><span style="font-size:12pt;">Ocean to Headwater and Headwater to Ocean fields</span></b><span style="font-size:12pt;">:</span></p><p style="margin:12pt 0in 12pt 1in; text-indent:-0.25in; background-image:initial; background-position:initial; background-size:initial; background-repeat:initial; background-attachment:initial; background-origin:initial; background-clip:initial;"><span style="font-size:10pt; font-family:&quot;Courier New&quot;;">o<span style="font-variant-numeric:normal; font-variant-east-asian:normal; font-variant-alternates:normal; font-kerning:auto; font-feature-settings:normal; font-variant-position:normal; font-stretch:normal; font-size:7pt; font-family:&quot;Times New Roman&quot;;">
</span></span><span style="font-size:12pt;">This layer was created though engineering assessment of the HUC
4 layer provided within the National Water Boundary Dataset. The hydraulic path
from either downstream from the headwaters or upstream from ocean was counted
to show precedence and priority based on longest flow paths. Some
assumptions were made for this effort:</span></p><ul>
<ul>
<ul>
<li><span style="font-size:12.0pt;">Modeling
would not occur on basins existing wholly outside of the continental US.
For locations that contribute to flow into the US, an inflow assumption
would be make at the boundary of the first HUC that contains portions of
united states territory. Basins existing outside of the US would be
removed from our lists/estimations.</span></li>
<li><span style="font-size:12.0pt;">All
HUCs with territory within the United States would be modeled using
Riverine methods. The methodology for small Caribbean territories for
example, or small islands within the Great Lakes will likely have a
combination of inland and coastal flooding.</span></li>
<li><span style="font-size:12.0pt;">Larger
Bay features are considered the boundary for riverine features, and not
dependent on downstream riverine routing, if the bay extends through
multiple HUCs (Example: Chesapeake Bay)</span></li>
<li><span style="font-size:12.0pt;">The
lower Mississippi River HUCs, and other similar areas on the largest few
drainages will likely need to be re-delineated for FFRD modeling
purposes, as currently drainages are split in ways that will be
complicated to model due to backwater impacts extending through multiple
HUCs, and or Feedback loops from the largest of reservoirs. There would
also concerns on fragility with Levees acting as boundaries of the HUCs.
Therefore, these areas are subject to change as we move though the FFRD
process.</span></li>
<li><span style="font-size:12.0pt;">Continental
United States (CONUS) basins will be prioritized until adequate data
sources (i.e., terrain/gridded precipitation or precipitation
alternative) is available for a given OCONUS HUC or HUC that covers
territory within the United States as well as a neighboring country.</span></li>
</ul>
</ul>
</ul><p style="margin:12pt 0in 0in 0.5in; text-indent:-0.25in; background-image:initial; background-position:initial; background-size:initial; background-repeat:initial; background-attachment:initial; background-origin:initial; background-clip:initial;"><span style="font-size:10pt; font-family:Symbol;">·<span style="font-variant-numeric:normal; font-variant-east-asian:normal; font-variant-alternates:normal; font-kerning:auto; font-feature-settings:normal; font-variant-position:normal; font-stretch:normal; font-size:7pt; font-family:&quot;Times New Roman&quot;;">
</span></span><b><span style="font-size:12pt;">DSAC and LSAC Risk:</span></b></p><p style="margin:12pt 0in 12pt 1in; text-indent:-0.25in; background-image:initial; background-position:initial; background-size:initial; background-repeat:initial; background-attachment:initial; background-origin:initial; background-clip:initial;"><span style="font-size:12pt;">o These
values were pulled from the <a href="https://nid.sec.usace.army.mil/#/"><span style="color:blue;">National Inventory of Dams</span></a> and the <a href="https://levees.sec.usace.army.mil/#/"><span style="color:blue;">National
Levee Database</span></a>. The values were then normalized by weighting the DSAC level and summing the total within a HUC 4 basin and combined into a third field for a
combined risk.</span></p><p style="margin:12pt 0in 0in 0.5in; text-indent:-0.25in; background-image:initial; background-position:initial; background-size:initial; background-repeat:initial; background-attachment:initial; background-origin:initial; background-clip:initial;"><span style="font-size:10pt; font-family:Symbol;">·<span style="font-variant-numeric:normal; font-variant-east-asian:normal; font-variant-alternates:normal; font-kerning:auto; font-feature-settings:normal; font-variant-position:normal; font-stretch:normal; font-size:7pt; font-family:&quot;Times New Roman&quot;;">
</span></span><b><span style="font-size:12pt;">NRI Score, Social Vulnerability Score, &amp; Riverine Flooding
Score:</span></b></p><p style="margin:12pt 0in 12pt 1in; text-indent:-0.25in; background-image:initial; background-position:initial; background-size:initial; background-repeat:initial; background-attachment:initial; background-origin:initial; background-clip:initial;"><span style="font-size:12pt;">o These
values were exported from <a href="https://www.fema.gov/flood-maps/products-tools/national-risk-index" target="_blank"><span style="color:blue;">FEMA National Risk Index</span></a> and
then normalized by total square miles within a HUC 4 basin.</span></p><p style="margin:12pt 0in 0in 0.5in; text-indent:-0.25in; background-image:initial; background-position:initial; background-size:initial; background-repeat:initial; background-attachment:initial; background-origin:initial; background-clip:initial;"><span style="font-size:10pt; font-family:Symbol;">·<span style="font-variant-numeric:normal; font-variant-east-asian:normal; font-variant-alternates:normal; font-kerning:auto; font-feature-settings:normal; font-variant-position:normal; font-stretch:normal; font-size:7pt; font-family:&quot;Times New Roman&quot;;">
</span></span><b><span style="font-size:12pt;">HUC4</span></b></p><p style="margin:12pt 0in 12pt 0.75in; text-indent:-0.25in; background-image:initial; background-position:initial; background-size:initial; background-repeat:initial; background-attachment:initial; background-origin:initial; background-clip:initial;"><span style="font-size:12pt;">o <i>Downloaded
from:</i> <a href="https://prd-tnm.s3.amazonaws.com/index.html?prefix=StagedProducts/Hydrography/WBD/National/GDB/" target="_new"><span style="color:blue;">https://prd-tnm.s3.amazonaws.com/index.html?prefix=StagedProducts/Hydrography/WBD/National/GDB/</span></a></span></p><p style="margin:12pt 0in 12pt 0.75in; text-indent:-0.25in; background-image:initial; background-position:initial; background-size:initial; background-repeat:initial; background-attachment:initial; background-origin:initial; background-clip:initial;"><span style="font-size:12pt;">o <i>Source:</i> <a href="https://hydro.nationalmap.gov/arcgis/rest/services/wbd/MapServer/2" target="_new"><span style="color:blue;">https://hydro.nationalmap.gov/arcgis/rest/services/wbd/MapServer/2</span></a></span></p><p style="margin:12pt 0in 12pt 1in; text-indent:-0.25in; background-image:initial; background-position:initial; background-size:initial; background-repeat:initial; background-attachment:initial; background-origin:initial; background-clip:initial;"><span style="font-size:10pt; font-family:&quot;Courier New&quot;;">o<span style="font-variant-numeric:normal; font-variant-east-asian:normal; font-variant-alternates:normal; font-kerning:auto; font-feature-settings:normal; font-variant-position:normal; font-stretch:normal; font-size:7pt; font-family:&quot;Times New Roman&quot;;">
</span></span><i><span style="font-size:12pt;">Description:</span></i><span style="font-size:12pt;"> HUC 4 polygons were extracted from the NHD dataset with
the following description...</span></p><p style="margin:12pt 0in 12pt 1.5in; text-indent:-0.25in; background-image:initial; background-position:initial; background-size:initial; background-repeat:initial; background-attachment:initial; background-origin:initial; background-clip:initial;"><span style="font-size:10pt; font-family:Wingdings;">§<span style="font-variant-numeric:normal; font-variant-east-asian:normal; font-variant-alternates:normal; font-kerning:auto; font-feature-settings:normal; font-variant-position:normal; font-stretch:normal; font-size:7pt; font-family:&quot;Times New Roman&quot;;">
</span></span><span style="font-size:12pt;">This file contains Hydrologic Unit (HU) polygon boundaries for
the United States, Puerto Rico, and the U.S. Virgin Islands. The data is a
seamless National representation of HU boundaries from 2 to 14 digits compiled
from U.S. Geological Survey (USGS) National Hydrography Dataset (NHD) and U.S.
Department of Agriculture (USDA) National Resources Conservation Service (NRCS)
Watershed Boundary Dataset (WBD) sources. This data is intended primarily for
geographic display and analysis of regional and national data and can also be
used for illustration purposes at intermediate or small scales (1:250,000 to
1:2,000,000).</span></p><p style="margin:12pt 0in; background-image:initial; background-position:initial; background-size:initial; background-repeat:initial; background-attachment:initial; background-origin:initial; background-clip:initial;"><span style="font-size:12pt;"> </span></p><p style="margin:12pt 0in; background-image:initial; background-position:initial; background-size:initial; background-repeat:initial; background-attachment:initial; background-origin:initial; background-clip:initial;"><span style="font-size:12pt;">The data below
originates from the FEMA Hazards website (<a href="https://hazards.fema.gov/nri/data-resources#gdbDownload" target="_new"><span style="color:blue;">FEMA Hazards NRI Data</span></a>) and was downloaded with
information compiled at the Census Tract level. </span><span style="font-size:12.0pt; color:black;">Census tracts that cross
HUC4 boundaries were added to the HUC4 basin that the majority of the Census
Tract fell within.</span></p><p style="margin:12pt 0in; background-image:initial; background-position:initial; background-size:initial; background-repeat:initial; background-attachment:initial; background-origin:initial; background-clip:initial;"><b><span style="font-size:12pt;">NRI Data:</span></b></p><ul>
<li><b><span style="font-size:12.0pt;">By
Sq Miles:</span></b></li>
<ul>
<li><i><span style="font-size:12.0pt;">Name:</span></i><span style="font-size:12.0pt;"> Normalized_NRI_Score_Composite_by_Sq_Miles</span></li>
<ul>
<li><span style="font-size:12.0pt;">Multiply
(National Risk Index - Value - Composite) by (Area (sq mi)) and sum the
tracts by HUC4 basin. Normalize those values to be between 0 to 1 by
dividing each result by the largest value calculated.</span></li>
</ul>
</ul>
<li><b><span style="font-size:12.0pt;">Ranked:</span></b></li>
<ul>
<li><i><span style="font-size:12.0pt;">Name:</span></i><span style="font-size:12.0pt;"> Ranked_NRI_Score_Composite_by_Sq_Miles</span></li>
<ul>
<li><span style="font-size:12.0pt;">Sorting
the
Normalized_Riverine_Flooding_Hazard_Type_Risk_Index_Score_by_Sq_Miles
layer from largest to smallest and ranking the values from 1 to 232.&gt;</span></li>
</ul>
</ul>
</ul><ul>
<li><b><span style="font-size:12.0pt;">By
Population:</span></b></li>
<ul>
<li><i><span style="font-size:12.0pt;">Name:</span></i><span style="font-size:12.0pt;"> Normalized_National_Risk_Index_Score_Composite_by_Population</span></li>
<ul>
<li><span style="font-size:12.0pt;">Multiply
(National Risk Index - Value - Composite) by (Population (2020)) and sum
the tracts by HUC4 basin. Normalize those values to be between 0 to 1 by
dividing each result by the largest value calculated.</span></li>
</ul>
</ul>
<li><b><span style="font-size:12.0pt;">Ranked:</span></b></li>
<ul>
<li><i><span style="font-size:12.0pt;">Name:</span></i><span style="font-size:12.0pt;"> Ranked_National_Risk_Index_Score_Composite_by_Population</span></li>
<ul>
<li><span style="font-size:12.0pt;">Sorting
the Normalized_National_Risk_Index_Score_Composite_by_Population layer
from largest to smallest and ranking the values from 1 to 232.</span></li>
</ul>
</ul>
</ul><ul>
<li><b><span style="font-size:12.0pt;">By
Structure:</span></b></li>
<ul>
<li><i><span style="font-size:12.0pt;">Name:</span></i><span style="font-size:12.0pt;"> Normalized_National_Risk_Index_Score_Composite_by_Structure</span></li>
<ul>
<li><span style="font-size:12.0pt;">Sum
(National Risk Index - Value - Composite) by HUC4 Basin and sum the
National Structure Inventory (NSI) by HUC4 basin. Multiply the two
values together for each HUC4 basin. Normalize those values to be
between 0 to 1 by dividing each result by the largest value calculated.
The NSI can be found here: <a href="https://nsi.sec.usace.army.mil/downloads/" target="_new"><span style="color:blue;">NSI Download Link</span></a>.</span></li>
</ul>
</ul>
<li><b><span style="font-size:12.0pt;">Ranked:</span></b></li>
<ul>
<li><i><span style="font-size:12.0pt;">Name:</span></i><span style="font-size:12.0pt;"> Ranked_National_Risk_Index_Score_Composite_by_Structure</span></li>
<ul>
<li><span style="font-size:12.0pt;">Sorting
the Ranked_National_Risk_Index_Score_Composite_by_Structure layer from
largest to smallest and ranking the values from 1 to 232.</span></li>
</ul>
</ul>
</ul><p style="margin:12pt 0in; background-image:initial; background-position:initial; background-size:initial; background-repeat:initial; background-attachment:initial; background-origin:initial; background-clip:initial;"><b><span style="font-size:12pt;">Social Vulnerability
Data:</span></b></p><ul>
<li><b><span style="font-size:12.0pt;">By
Sq Miles:</span></b></li>
<ul>
<li><i><span style="font-size:12.0pt;">Name:</span></i><span style="font-size:12.0pt;"> Normalized_Social_Vulnerability_Score_by_Sq_Miles</span></li>
<ul>
<li><span style="font-size:12.0pt;">Multiply
(Social Vulnerability - Score) by (Area (sq mi)) and sum the tracts by
HUC4 basin. Normalize those values to be between 0 to 1 by dividing each
result by the largest value calculated.</span></li>
</ul>
</ul>
<li><b><span style="font-size:12.0pt;">Ranked:</span></b></li>
<ul>
<li><i><span style="font-size:12.0pt;">Name:</span></i><span style="font-size:12.0pt;"> Ranked_Social_Vulnerability_Score_by_Sq_Miles</span></li>
<ul>
<li><span style="font-size:12.0pt;">Sorting
the Ranked_Social_Vulnerability_Score_by_Sq_Miles layer from largest to
smallest and ranking the values from 1 to 232.</span></li>
</ul>
</ul>
</ul><ul>
<li><b><span style="font-size:12.0pt;">By
Population:</span></b></li>
<ul>
<li><i><span style="font-size:12.0pt;">Name:</span></i><span style="font-size:12.0pt;"> Normalized_Social_Vulnerability_Score_by_Population</span></li>
<ul>
<li><span style="font-size:12.0pt;">Multiply
(Social Vulnerability - Score) by (Population (2020)) and sum the tracts
by HUC4 basin. Normalize those values to be between 0 to 1 by dividing
each result by the largest value calculated.</span></li>
</ul>
</ul>
<li><b><span style="font-size:12.0pt;">Ranked:</span></b></li>
<ul>
<li><i><span style="font-size:12.0pt;">Name:</span></i><span style="font-size:12.0pt;"> Ranked_Social_Vulnerability_Score_by_Population</span></li>
<ul>
<li><span style="font-size:12.0pt;">Sorting
the Ranked_Social_Vulnerability_Score_by_Population layer from largest
to smallest and ranking the values from 1 to 232.</span></li>
</ul>
</ul>
</ul><ul>
<li><b><span style="font-size:12.0pt;">By
Structure:</span></b></li>
<ul>
<li><i><span style="font-size:12.0pt;">Name:</span></i><span style="font-size:12.0pt;"> Normalized_Social_Vulnerability_Score_by_Structure</span></li>
<ul>
<li><span style="font-size:12.0pt;">Sum
(Social Vulnerability - Score) by HUC4 Basin and sum the National
Structure Inventory (NSI) by HUC4 basin. Multiply the two values
together for each HUC4 basin. Normalize those values to be between 0 to
1 by dividing each result by the largest value calculated. The NSI can
be found here: <a href="https://nsi.sec.usace.army.mil/downloads/" target="_new"><span style="color:blue;">NSI Download Link</span></a>.</span></li>
</ul>
</ul>
<li><b><span style="font-size:12.0pt;">Ranked:</span></b></li>
<ul>
<li><i><span style="font-size:12.0pt;">Name:</span></i><span style="font-size:12.0pt;"> Ranked_Social_Vulnerability_Score_by_Structure</span></li>
<ul>
<li><span style="font-size:12.0pt;">Sorting
the Ranked_Social_Vulnerability_Score_by_Structure layer from largest to
smallest and ranking the values from 1 to 232.</span></li>
</ul>
</ul>
</ul><p style="margin:12pt 0in; background-image:initial; background-position:initial; background-size:initial; background-repeat:initial; background-attachment:initial; background-origin:initial; background-clip:initial;"><b><span style="font-size:12pt;">Riverine Flooding Data:</span></b></p><ul>
<li><b><span style="font-size:12.0pt;">By
Sq Miles:</span></b></li>
<ul>
<li><i><span style="font-size:12.0pt;">Name:</span></i><span style="font-size:12.0pt;"> Normalized_Riverine_Flooding_Hazard_Type_Risk_Index_Score_by_Sq_Miles</span></li>
<ul>
<li><span style="font-size:12.0pt;">Multiply
((Riverine Flooding - Hazard Type Risk Index Score) by (Area (sq mi))
and sum the tracts by HUC4 basin. Normalize those values to be between 0
to 1 by dividing each result by the largest value calculated.</span></li>
</ul>
</ul>
<li><b><span style="font-size:12.0pt;">Ranked:</span></b></li>
<ul>
<li><i><span style="font-size:12.0pt;">Name:</span></i><span style="font-size:12.0pt;"> Ranked_Riverine_Flooding_Hazard_Type_Risk_Index_Score_by_Sq_Miles</span></li>
<ul>
<li><span style="font-size:12.0pt;">Sorting
the
Normalized_Riverine_Flooding_Hazard_Type_Risk_Index_Score_by_Sq_Miles
layer from largest to smallest and ranking the values from 1 to 232.</span></li>
</ul>
</ul>
</ul><ul>
<li><b><span style="font-size:12.0pt;">By
Population:</span></b></li>
<ul>
<li><i><span style="font-size:12.0pt;">Name:</span></i><span style="font-size:12.0pt;"> Normalized_Riverine_Flooding_Hazard_Type_Risk_Index_Score_by_Population</span></li>
<ul>
<li><span style="font-size:12.0pt;">Multiply
((Riverine Flooding - Hazard Type Risk Index Score) by (Population
(2020)) and sum the tracts by HUC4 basin. Normalize those values to be
between 0 to 1 by dividing each result by the largest value calculated.</span></li>
</ul>
</ul>
<li><b><span style="font-size:12.0pt;">Ranked:</span></b></li>
<ul>
<li><i><span style="font-size:12.0pt;">Name:</span></i><span style="font-size:12.0pt;"> Ranked_Riverine_Flooding_Hazard_Type_Risk_Index_Score_by_Population</span></li>
<ul>
<li><span style="font-size:12.0pt;">Sorting
the
Normalized_Riverine_Flooding_Hazard_Type_Risk_Index_Score_by_Population
layer from largest to smallest and ranking the values from 1 to 232.</span></li>
</ul>
</ul>
</ul><p style="margin-bottom:0in;">
</p><ul>
<li><b><span style="font-size:12.0pt;">By
Structure:</span></b></li>
<ul>
<li><i><span style="font-size:12.0pt;">Name:</span></i><span style="font-size:12.0pt;"> Normalized_Riverine_Flooding_Hazard_Type_Risk_Index_Score_by_Structure</span></li>
<ul>
<li><span style="font-size:12.0pt;">Sum
((Riverine Flooding - Hazard Type Risk Index Score) by HUC4 Basin and
sum the National Structure Inventory (NSI) by HUC4 basin. Multiply the
two values together for each HUC4 basin. Normalize those values to be
between 0 to 1 by dividing each result by the largest value calculated.
The NSI can be found here: <a href="https://nsi.sec.usace.army.mil/downloads/" target="_new"><span style="color:blue;">NSI Download Link</span></a>.</span></li>
</ul>
</ul>
<li><b><span style="font-size:12.0pt;">Ranked:</span></b></li>
<ul>
<li><i><span style="font-size:12.0pt;">Name:</span></i><span style="font-size:12.0pt;"> Ranked_Riverine_Flooding_Hazard_Type_Risk_Index_Score_by_Structure</span></li>
<ul>
<li><span style="font-size:12.0pt;">Sorting
the
Normalized_Riverine_Flooding_Hazard_Type_Risk_Index_Score_by_Structure
layer from largest to smallest and ranking the values from 1 to 232.</span></li>
</ul>
</ul>
</ul><span style="font-family:Arial, sans-serif; font-size:10pt; text-indent:-0.25in;"></span>