Description: <DIV STYLE="text-align:Left;"><DIV><DIV><P><SPAN>The layer supports Maryland State Highway </SPAN><SPAN><SPAN>Administration </SPAN></SPAN><SPAN>(SHA) leadership and planners as they endeavor to mitigate or prevent the impacts of sea level change resulting from land surface subsidence and rising sea levels. This HVI uses weighted roadway characteristics - evacuation route and functional class - to standardize the impending hazard - projected sea-level rise - along segments of Maryland State Highway </SPAN><SPAN><SPAN>Administration </SPAN></SPAN><SPAN>(SHA) centerlines for a particular scenario. </SPAN></P><P><SPAN>Methodology:</SPAN></P><P><SPAN><SPAN>US Army Corps of Engineers (USACE) provide the sea level change (SLC) estimate-1. SLC is localized using water elevations collected from a qualifying-2 National Oceanic and Atmospheric Administration (NOAA) tidal reference station - NOAA observations are transformed from tidal datum to North American Vertical Datum of 1988 (NAVD88). A final correction for glacial isostatic adjustment and land subsidence is applied to create an SLC value for the official project year, 2020.</SPAN></SPAN></P><P><SPAN>Year ;Tide: SLC Value; Tide: SLC Value</SPAN></P><P><SPAN><SPAN>2020; MSL: 0.00; MHHW: 0.67</SPAN></SPAN></P><P><SPAN><SPAN>2050; MSL: 1.28; MHHW: 1.95</SPAN></SPAN></P><P><SPAN>2100; MSL: 4.91; MHHW: 5.58</SPAN></P><P /><P><SPAN><SPAN>The best available LiDAR, at time of creation, contributes to a county-wide Digital Elevation Model (DEM). The LiDAR-derived DEM is the base from which the SLC value is applied.</SPAN></SPAN></P><P><SPAN>The SLC adjusted DEM serves as elevation data for a Level 1 Coastal Only HAZUS-MH (FEMA) Flood analysis. The shoreline of the county level study is limited to Deal Island Neck. Breakpoints segment the shorline to capture flooding sources, locations, and heights outlined in the FEMA Flood Insurance Study for Anne Arundel County, Maryland - #24003CV000B; Effective: February 18, 2015.</SPAN></P><P STYLE="margin:1 1 1 0;"><SPAN>Flooding Source; Location; Annual Chance Event: Eleveation (ft) NAVD88</SPAN></P><P><SPAN>Chesapeake Bay; Patapsco River; 10%: 4.05, 4%: *, 2%: 4.6, 1%: 4.9, 0.2%: 6.35</SPAN></P><P><SPAN>Chesapeake Bay; Severn Run; 10%: 3.7, 4%: *, 2%: 4.3, 1%: 4.5, 0.2%: 5.95</SPAN></P><P /><P><SPAN>Classified stillwater elevations:</SPAN></P><P><SPAN><SPAN>0 = less than or equal to one-tenth of a foot (<= 0.10')</SPAN></SPAN></P><P><SPAN><SPAN>1 = greater than one-tenth foot and less than or equal to a half foot (> 0.10' and <= 0.5')</SPAN></SPAN></P><P><SPAN><SPAN>2 = greater than a half foot and less than or equal to one foot (> 0.5' and <= 1')</SPAN></SPAN></P><P><SPAN><SPAN>3 = greater than one foot and less than or equal to two foot (> 1' and <= 2')</SPAN></SPAN></P><P><SPAN><SPAN>4 = greater than two foot (> 2')</SPAN></SPAN></P><P><SPAN /></P><P><SPAN>Hazard Vulnerability Index (HVI):</SPAN></P><P><SPAN>RISK = (Evacuation Route * 0.5 + 1.0) * ((classified stillwater elevation + .01) / 4.0) * (1.0 / Functional Class) * 0.70</SPAN></P><P><SPAN /></P><P><SPAN><SPAN>Hazard Vulnerability Index Classification (HVI Class):</SPAN></SPAN></P><P><SPAN>1 = RISK <= 0.003</SPAN></P><P><SPAN>2 = RISK > 0.003 and RISK <= 0.15</SPAN></P><P><SPAN>3 = RISK > 0.15 and RISK <= 0.264</SPAN></P><P><SPAN>4 = RISK > 0.264</SPAN></P><P><SPAN /></P><P><SPAN>-1 The SLC rate used in this study was calculated using the USACE High Curve. See </SPAN><A href="http://www.corpsclimate.us/ccaceslcurves.cfm"><SPAN><SPAN>http://www.corpsclimate.us/ccaceslcurves.cfm</SPAN></SPAN></A><SPAN><SPAN>for more detail.</SPAN></SPAN></P><P><SPAN><SPAN>-2 Closest station with historic records of 40 years or greater. An average or qualifying stations was chosen when the nearest station’s records were insufficient. </SPAN></SPAN></P><P><SPAN><SPAN>* - Four percent annual chance is interpolated value</SPAN></SPAN></P><P><SPAN /></P><P><SPAN>RE SHA CENTERLINES:</SPAN></P><P><SPAN>The 2021 Functional Class linear file was created with the process of dynamic segmentation, using SHA's Routes and HPMS linear event table that contain ROUTEID, beginning and ending mile point fields and the Functional Classification field, "FUNCTIONAL_CLASS".</SPAN></P><P><SPAN>Revised HPMS Functional Classification Codes:</SPAN></P><P STYLE="margin:0 0 0 0;"><SPAN>1 = Interstate</SPAN></P><P STYLE="margin:0 0 0 0;"><SPAN>2 = Other Freeways and Expressways </SPAN></P><P STYLE="margin:0 0 0 0;"><SPAN>3 = Other Principal Arterial </SPAN></P><P STYLE="margin:0 0 0 0;"><SPAN>4 = Minor Arterial </SPAN></P><P STYLE="margin:0 0 0 0;"><SPAN>5 = Major Collector </SPAN></P><P STYLE="margin:0 0 0 0;"><SPAN>6 = Minor Collector </SPAN></P><P STYLE="margin:0 0 0 0;"><SPAN>7 = Local </SPAN></P></DIV></DIV></DIV>
Copyright Text: Maryland State Highway Administration (MDSHA), Eastern Shore Regional GIS Cooperative (ESRGC), National Oceanic and Atmospheric Administration (NOAA), United States Army Corps of Engineers (USACE), United States Geoglogical Survey (USGS),FHWA, Maryland counties and Metropolitan Planning Organizations